description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
|---|---|---|
FEDERALLY SPONSORED RESEARCH
Not Applicable
SEQUENCE LISTING OR PROGRAM
Not Applicable
BACKGROUND
1. Field of Invention
This invention relates to a braking and steering device, specifically to provide braking and more particularly improved control capabilities for a personal watercraft such as a Waverunner®, Jet Ski®, SeaDoo®, or other such vessel.
2. Description of Prior Art
Currently more than one million personal watercraft, (PWC), are in use by individuals for recreation and boating enjoyment, resort and marina rental facilities, lifeguard and rescue organizations, and racing and entertainment entities. PWC employ a pump that receives water from an intake, pressurizes the water with rapidly spinning impeller blades, and expels the pressurized water through a nozzle or “jet”. PWC are generally manufactured without braking or auxiliary control mechanisms, rely on propulsion for control (steering), and reduction of propulsion for slowing.
Inventors created several devices designed to improve control or braking characteristics of personal watercraft in such a way as to have minimal effect on slowing the vessel or significantly improving control. U.S. Pat. No. 5,092,260 to Mardikian (1992) discloses movable and fixed plate and drive shaft braking mechanisms; however movable/fixed plate devices may interfere with vessel trim, and operation of the hand lever may be exceedingly difficult. Drive shaft braking mechanisms are inherently ineffective due to the fact that once throttle is reduced, the pump intake water flow is significantly reduced, rendering drive shaft spin negligible for braking purposes. U.S. Pat. No. 5,193,478 also to Mardikian (1993) describes a trimming, steering and braking assembly that uses plates or flaps to independently or dependently slow or turn the watercraft. This particular design lacks effective angular position of the flaps relative to water-flow impedance, as well as not offering the advantageous mechanical advantage mechanism of present invention necessary to facilitate deployment of flaps. Another invention designed improve performance of PWC, U.S. Pat. No. 4,961,396 to Sasagawa (1990), proposes a trim plate adjusting device to optimize performance of the PWC under varying rider weight conditions. The trim plate application is unsuitable for improved control such as steering or slowing the forward momentum of a PWC.
Another invention designed for jet propelled watercraft, U.S. Pat. No. 5,934,954 to Schott et al. (1999), proposes a gate device that requires a volume of water to be flowing through the jet nozzle, potentially propelling the watercraft in forward motion, before the gate device will be effective.
A similar invention using a nozzle gate device to stop the watercraft, U.S. Pat. No. 5,755,601 to Jones (1998) utilizes an electronic controller and servo mechanism to actuate the cable mechanism and operate the gate. This invention again fails meet the need of applying a stopping or steering force to a watercraft minus the positive water flow through the jet nozzle.
Another invention based on the bucket or nozzle gate, U.S. Pat. No. 5,607,332 to Kobayashi et al. (1997), adds a foot pedal operation of the existing art nozzle gate concept Although the foot pedal design provides for a novel method of actuating a reverse bucket mechanism, it fails to address the problems inherent to the gate or bucket mechanisms, namely they require a volume of water to be propelled through the nozzle to have any effect.
Yet another invention designed for improved watercraft control, U.S. Patent Application 20010018300 to Spade (2001) relies on propulsion or jet flow, for control or braking, This device, while functional does not allow for any improved control or braking without positive water flow through the propulsion mechanism. This device also contains a multitude of claims and components, likely increasing the cost of installation and ownership over more straight-forward designs. What this invention also fails to address are the riders who require control and braking without the application of throttle, or increasing power output through the jet nozzle.
These devices, as all braking devices heretofore, do not provide significant braking capabilities or noticeably improved control or turning without applied throttle, and suffer from a number of disadvantages:
(a) Movable/fixed plate devices are expensive to manufacture, require replacement of original manufacture equipment, have limited effect on slowing or stopping, and can potentially interfere with, or counteract the existing nozzle trim mechanisms available subsequent to 1992;
(b) Rigid assemblies are fixed and therefore difficult to adjust to varying conditions;
(c) Rigid, plate devices suffer from lack of independent side (left/right) control by the rider, preventing effective adjustment and control under normal and extreme riding conditions;
(d) Because of the nature of existing art in water intake and output in PWC, braking devices designed for drive shaft application do not noticeably improve braking capabilities, specifically when braking or steering is required without the application of throttle;
(e) Trim plate-type devices, although providing a level of improved hydrodynamics relating to angle of plane, are designed to facilitate water flow under the ride plate. Braking requires impedance of water flow to reduce speed, therefore reducing the effectiveness of these devices, and creating an increased level of difficulty pulling or operating the hand lever, while the plate device attempts to work against the flow of water.
(f) Control mechanisms which rely on any volume of water flowing from the jet nozzle for actuation of braking or steering, do not account for riders in the coasting (no water volume through jet) attitude, or riders who instinctively let off the throttle to dock or otherwise stop forward motion.
OBJECTS AND ADVANTAGES OF THE INVENITON
Primarily, present invention provides substantial improvement in rider and bystander safety by impeding the flow of water under the PWC ride plate thereby effectively slowing and braking of the PWC. Additionally, present invention provides steering capabilities to PWC with or without propulsion. It is thus the object of the present invention to provide a PWC rider/operator ability to significantly decrease stopping distance between another boat, person, object, other PWC, dock or other obstruction as well as to provide steering capability to avoid such objects and improve PWC performance.
It is another object of the present invention to allow steering, maneuvering and increased vessel control without jet propulsion or throttle engaged.
It is another object of the present invention to provide augmented steering control beyond existing art of jet nozzle control by actuating water-impeding paddles individually.
It is another object of the present invention to provide steering and braking capabilities when no throttle is applied to provide decreased risk of injury or death to rider or bystander;
Such a device provides a mechanism that is easy to use and actuate by means of hand levers and integrated steering control.
Advantageously, the present invention provides a device with increased reliability and resistance to elements.
As embodied and broadly described herein, the invention provides a device that can be actuated by riders/operators of all (legal) ages, by a variety of means including hand levers and steering.
It is another object of the present invention to allow for individual deployment of each braking control surface, facilitating steering with the throttle off.
It is another object of this invention to utilize many existing materials and assemblies familiar to those with knowledge of the art, thereby reducing the cost to manufacture, install, or purchase this invention over inventions of prior art.
Advantageously, each said braking control paddle surface can be deployed with the throttle engaged, thereby effectively enhancing maneuverability and steering performance characteristics of the watercraft while under power.
Additionally, each said braking device incorporates a series of angled ribs on the backside of each paddle, wherein said ribs increase the effectiveness of deployment by water flow force.
Further objects and advantages are to provide a device which can be used for braking, steering and control of a PWC whether or not it is under power, which is simple and instinctive to use, which significantly reduces stopping distance beyond current inventions, which is easy to maintain and operate, which is retractable in the “neutral” position, which contains rounded and safe surfaces, which requires no replacement of original manufactured equipment, and which obviates need for jumping off PWC in the event of potential collision. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
SUMMARY
In accordance with the present invention a braking device that comprises a combination manually actuated lever mechanism connected to a mechanical leveraging device, which engages a dual drop-down paddle braking mechanism, each brake surface mechanism containing means for increased water flow impingement and deployment facilitation, either (left or right) paddle capable of independent deployment, providing steering advantage and capability for a PWC.
It is another object of the present invention to provide control of speed and steering capabilities beyond the existing art when applied by the rider of PWC with no propulsion applied. Additionally, it is the object of present invention to increase performance and control of PWC by impeding water flow from the ride plate aft, under propulsion, thereby enhancing and augmenting steering and control capabilities of the PWC. Another object of present invention is to incorporate a mechanical advantage mechanism facilitating the lever operation and providing for maximum leverage in deployment of said brake surfaces.
Yet another object of present invention is to incorporate a series of angled ribs on the backside of each paddle surface, increasing the effectiveness of deployment by water flow force and leverage advantage during deployment of said braking surfaces.
It is further the object of the present invention to employ many mechanisms that are commonly available and familiar to those versed in the art, thereby reducing the cost to manufacture, install, or purchase the invention thereby providing wider access to the present invention than prior art.
DRAWINGS
Drawing Figures
FIG. 1 shows invention in un-deployed position mounted on personal watercraft ride plate.
FIG. 2 shows invention in deployed position mounted on personal watercraft ride plate.
FIG. 3 shows deployed hand-actuated mechanism providing mechanical advantage and necessary cable travel.
FIG. 4 shows hand-actuated mechanism designed for rider ergonomics at rest in un-deployed position.
FIG. 5 shows braking mechanism surfaces deployed as mounted on personal watercraft ride plate.
FIG. 6 shows braking mechanism surfaces in neutral as mounted on personal watercraft ride plate.
FIG. 7 shows cutaway of cable splitter design, where single front cable exits rear PWC transom by way of bulkhead fitting and is integrated into a splitting device, converting the single cable into two cable housings, enabling the actuation of both braking mechanism.
FIG. 8 shows cutaway of cable splitter design, where single front cable exits rear PWC transom by way of bulkhead through-hull fitting and is integrated into a splitting device, converting the single cable into two cable housings, with braking mechanisms deployed.
FIG. 9 shows close view of deployed braking mechanisms, return springs extended, cable splitter, and inside bulkhead mount bushing showing water flow direction.
FIG. 10 shows retracted braking mechanisms, return springs retracted, resting cable splitter, and inner hull mount bushing showing water flow direction.
FIG. 11 shows means to engage synchronized control surface deployment by means of steering the PWC handlebars for turning left.
FIG. 12 shows the hull mount cable and lever system, which enhances the mechanical advantage of transfer of force from the actuator levers to control surfaces in such a way as to allow easy deployment of braking and steering paddle control surfaces with maximum force.
FIG. 13 shows means to engage synchronous control surface deployment by means of steering the PWC handlebars for right turning.
FIG. 14 shows brake deployment in fully engaged position.
FIG. 15 shows brake and steering control surfaces fully retracted in the neural position.
REFERENCE NUMBERS IN DRAWINGS
22 Hand control mechanism
24 Hand control pivot clamp and cable mount
26 Single forward actuator cable
28 Brake surface deployed
30 Brake surfaces retracted
32 Bulkhead cable through-hull fitting
34 Cable splitter block
36 Cable splitter mount
38 Rear dual actuator cables
40 Brake device paddle pivot housings
42 Rear paddle return springs
44 Ride plate surface
46 Cable splitter mounting bolts
48 Pivot housing cable connector bushings
50 Cable rotation pulley
52 Existing PWC handlebar assembly
54 Steering control actuator lever
56 Cable ball ends
58 Enhanced steering control mechanism
60 Mechanical advantage main housing plate hull mount
62 Throttle lever—prior art
64 Standard clevis connector
66 Mechanical advantage main housing plate
68 Dual cable mechanical advantage pivot arm
70 Cable housing attachment point
72 Cable splitter
74 Cable splitter main frame
76 Double acting cable captured pin slots
78 Augmented steering engagement activator
80 Clamp collar compression zone plate
82 Standard marine grade flexible cable
84 Existing PWC main steering post
86 Captivated floating cables
88 Lever activated engagement clamp collar
90 Clamp collar pivot point
92 Brake surface showing angled ribs
DETAILED DESCRIPTION
Description-FIGS. 1 , 2 , 3 , 4 , 5 , 6 , 7 , 9 , 10 , 12 -Prefered Embodiment
A preferred embodiment of the braking device of the present invention is illustrated in FIG. 1 (un-deployed view) and FIG. 2 (deployed view) wherein the rider activates the braking mechanism by pulling a hand lever 22 . The control device consists of a hand-operated actuating mechanism 22 , 24 and 26 , which activates a single forward actuator cable 26 running to a mechanical advantage main housing plate hull mount 62 and mechanism 60 and to rear control surface paddles 28 and 30 . In the preferred embodiment, the hand mechanism and the control surface paddles are comprised of machined aluminum, but can consist of any rigid material that can be shaped to conform to the required configuration, and withstand exposure to elements, including fresh water, salt water, sand, mud, sunlight, hot and cold temperatures, and applied pressure. Other materials include stainless steel, carbon fiber, nylon, hardened rubber, graphite composite, various plasticized products, or other metal products.
The hand actuator mechanism 22 provides a twenty degree movement at the point of actuation to the cable assembly illustrated FIG. 3 thereby increasing the effective travel on the rear control paddles 28 , 30 as shown in FIG. 5 . At rest, or in the un-deployed position, shown in FIG. 4 and FIG. 6, the hand lever and control paddles return to a retracted position by means of retracting springs 42 . The hand actuator is mounted on the left handlebar of the PWC by means of a hand control pivot clamp and cable mount 24 . The hand actuator is connected to the rear assembly by means of a housed cable 26 .
In FIG. 12, invention contains said mechanical advantage main housing 60 , which enhances the mechanical advantage of transfer of force from the actuator levers to control surfaces in such a way as to allow easy deployment of levers with maximum force exerted on the brake control surfaces by means of cable mechanical advantage pivot arms 68 .
The rear cable assembly of the invention as shown in FIG. 7 connects to the forward actuating mechanism by means of a housed control cable 82 , whereby the single cable 26 runs through the inside of PWC body to the mechanical advantage main housing plate hull mount 60 , and exits the rear transom of the PWC by means of a standard bulkhead through-fitting 32 . The through-fitting provides for a means of passing the cable through the PWC hull, without binding or obstructing the movement of the cable, and providing for a watertight seal. The single cable is fixed to a cable splitter mechanism 34 in the rear of the PWC comprised of machined aluminum and affixed to a secondary set of rear-mounted cables 38 , which are of stainless steel and friction-reducing material construction.
A cable splitter mount 36 comprised of machined aluminum or other suitable material secures the cable splitter mechanism 34 to the hull of the PWC by means of mounting screws 46 comprised of stainless steel or other corrosion-resistant material. The cable splitter mount further allows the rear dual actuator cables to terminate and connect to the single forward actuator cable by means of the cable splitter mechanism. In other embodiments, the rear dual actuator cables may pass through the cable splitter mount without mating with the cable splitter mechanism, utilizing two bulkhead through-hull fittings and two independently operated control mechanisms allowing each of the brake surfaces to deploy independent of one another.
Rear actuator control cables for augmented steering control 38 , commonly comprised of flexible stainless steel outer housings, which insert into the pivot housing cable bushings 48 , allowing the control cable 38 to pass into and be mounted to the brake device cable rotating pulley 50 by means of cable ball ends 56 . In the un-deployed position FIG. 7, FIG. 3, forward 26 and rear cables 38 are at rest with the brake surfaces 30 retracted by means of rear paddle return springs 42 . Said return springs are comprised of stainless steel or other common corrosion-resistant material, and are fixed to the top edge of the brake surface and top of the pivot housings 40 by means of standard mounting screws.
Brake surfaces 28 , 30 are comprised of machined aluminum or other common corrosion-resistant material and fixed to brake device pivot housings 40 in such a way as to allow the brake devices to pivot by means of cable tension or return spring tension. Brake device pivot housings are mounted to the PWC common ride plate 44 by means of common corrosion-resistant bolts. The brake surfaces are of a size that will provide a reduction of PWC water flow and forward momentum when deployed FIG. 9, and while in the retracted position FIG. 10 do not interfere with the normal forward water low and momentum of the PWC. The rear surface area of each braking paddle incorporates a series of angled ribs 92 increasing the effectiveness of deployment by water flow force and leverage advantage during deployment of said braking surfaces.
FIG. 11 -Additional Embodiments
Additional embodiments are shown in FIG. 11, where each of the brake surfaces may be deployed independently by means of hand controls. This embodiment requires the addition of an enhanced steering control mechanism 58 and additional bulkhead through-hull fitting 32 . Also required for this embodiment is the elimination of the cable splitter mechanism 34 . This embodiment allows the rider to steer the PWC when coasting, when no power is applied, and no water flowing through the jet nozzle.
FIG. 12 -Alternative Embodiments
There are various possibilities with regard to the composition of materials, placement of clamps and actuating devices, cable type, lever type, mounting hardware, paddle size and means of actuating the brake surfaces so as to slow, stop or facilitate steering for the rider of the PWC.
One variation of the embodiment shown in FIG. 12 is integrated steering, wherein the steering devices are controlled through the steering movement of the existing handlebars, and the brake function is hand controlled. This simplifies the operation for the rider, eliminates additional hand controls, and includes an enhanced steering control mechanism 58 , a mechanical advantage main housing mechanism 60 , augmented steering engagement activator plate 78 , as well as most components in aforementioned preferred embodiment.
Advantages
From the description above, a number of advantages of my braking and control device for PWC become evident over prior art:
a) The vertical alignment of the brake surfaces provide effective impedance to the ride plate water flow, generating an approximate seventy percent increase in braking power over the simple reduction or elimination of throttle.
b) Ridges on the brake surfaces create a cupping action increasing the amount of water flow impingement and providing leverage to facilitate deployment of said braking surfaces.
c) The retractable nature of the brake surfaces remove water flow impedance when in the retracted position, allowing the full performance characteristics of any PWC to be employed, and reducing the risk of injury to the rider.
d) Additional advantages of the retracting brake surfaces include reduced risk of damage to the units when trailering or beaching the watercraft.
e) The nature if the invention allows for either original factory installation of the invention or as an after-market addition to PWC already in use.
f) Configuration of braking control surfaces as described herein provides for enhanced control of PWC, without compromising the performance of the watercraft. The nature of the braking control surfaces allows deployment of a single surface for turning, or both surfaces simultaneously for braking, without causing the PWC to unduly dive or otherwise loose originally designed performance integrity.
g) The hull mount cable lever system as described herein enhances the mechanical advantage of transfer of force from the actuator levers to control surfaces in such a way as to allow easy deployment of paddles with maximum force exerted on the brake control surfaces.
h) Integrated steering control, as described herein, facilitates ease of operation combined with enhanced performance characteristics of the PWC.
i) The employment of many common mechanisms in this invention familiar to those versed in the art facilitates operation, installation, and reduction of cost to manufacture. Operation—FIGS. 3, 4 , 7 , 8 , 11 , 14 ,
The manner of operating the braking and control device to slow or stop a PWC is almost identical to the operation of brake devices in present use on bicycles and motorcycles. Namely, the rider, in a seated or upright position, pulls on the hand actuating lever FIG. 3 to achieve deployment of the brake control surfaces FIG. 5, while releasing the prior art throttle lever 62 . By pulling on the hand-actuating lever 22 , the rider creates tension on the forward cable assembly 26 . Said cable assembly exerts force on the hull mount cable lever mechanism FIG. 14, creating a mechanical advantage delivered to, and deploying, said braking control surfaces FIG. 8 . To release the brakes, the rider releases the hand-actuating lever FIG. 4, thereby releasing tension of said forward cable and hull mount cable mechanism respectively, returning the brake control surfaces to the retracted or un-deployed position FIG. 7 by means of rear paddle return springs 42 .
Alternatively, as shown in FIG. 11, the rider may deploy said brake control surfaces by said means of a single hand lever, and independently deploy the integrated steering mechanism by means of a separate lever 54 . In this embodiment, the rider can choose to deploy both said brake control surface simultaneously by means of said hand actuating lever, or deploy said integrated steering mechanism by means of a smaller lever mounted on the same handlebar FIG. 11 allowing the handlebar steering to actuate each brake, or steering, control surface independently.
In order to fully understand and appreciate the benefits of one embodiment of present invention wherein deploying the integrated steering mechanism FIG. 13, the operator, with or without throttle applied, pulls the steering control actuator lever 54 , which in turn pulls the single forward actuator cable 26 engaging the enhanced steering control mechanism 58 and the steering paddle engagement plate 52 therein. The enhanced steering control mechanism incorporates several advantageous means to transfer steering control from the existing PWC handlebar assembly 52 , and existing PWC main steering post 84 to the said brake surfaces 28 , 30 . As the said steering actuator lever is pulled, said actuator cable engages the lever activated engagement clamp collar 88 containing means for clamping to said main steering post with clamp collar pivot pin 90 and clamp collar compression zone 80 . Engaged, said integrated steering mechanism provides means for individual deployment of said brake surfaces by turning the augmented steering engagement actuator plate 78 containing double acting cable captured pin slots 76 , thereby engaging one of two captivated floating cables 86 by means of said captured pin slots and allowing the other of two said captivated floating cables to float or rest in the un-deployed position.
When said captivated floating cables 86 contained within standard marine grade flexible cable 82 are engaged, the energy or pull is transferred to said mechanical advantage main housing 66 by means of a cable splitter main frame 74 assembly and a cable splitter 72 , whereby said single forward actuator cable 26 is separated into two cables by means of said cable splitter. Both cables attach to the hull mount cable lever system 60 containing means for applying mechanical advantage through the cable housing attachment point 70 and terminate via standard clevis connectors 64 on the dual cable mechanical advantage pivot arm 68 attached to said mechanical advantage main housing plate 66 .
When engaged, said pivot arms 68 pivot and engage rear standard marine grade flexible cables by means of standard clevis connectors. Rear cables attach to said mechanical advantage main housing plate by means of said cable housing attachment points and exit the inner PWC hull by means of bulkhead cable through-hull fittings 32 whereby said rear cables connect to brake device paddle pivot housings 40 by means of pivot housing cable connector bushings 48 . Said brake device paddle pivot housings connect to the PWC existing ride plate surface 44 by means of standard bolts and contain the cable rotation pulley 50 , rear paddle. return springs 42 , cable ball ends 56 , and said brake surfaces 28 , 30 , providing means for independent deployment and retraction of said brake surfaces. Ribs incorporated into said rear brake surfaces 92 create a cupping action increasing the effectiveness of deployment by water flow force and leverage advantage during deployment of said braking surfaces. Conclusion, Ramifications, and Scope
Accordingly, the reader will see that the braking and control device of this invention can be used to brake PWC with or without propulsion, can be used to steer PWC with or without propulsion, enhance the steering and performance characteristics of PWC, and provide control and safety improvements previously unavailable for PWC.
In addition, this invention can be factory installed by the manufacturer, or by an authorized technician as a safety or control accessory.
Furthermore, the invention has the additional advantages in that:
It is instinctive and easy to operate;
It is made of superior, corrosion-resistant materials that improve reliability,
It can be easily installed and maintained, by manufacturer or rider;
It can be deployed effectively under varying propulsion and coasting environments;
It is unobtrusive, in that it is retractable;
It will not interfere with the newer generation PWC that contain a jet nozzle that serves to propel, steer and trim the watercraft;
It will supplement and augment the capabilities of newer generation PWC that contain a jet nozzle that serves to propel, steer and trim the watercraft;
The hull mount cable lever mechanism provides mechanical advantage for ease of operation, and effective use of energy in deployment of braking and steering surfaces;
It allows the operator to slow the vessel, as required, under a variety of conditions;
In several embodiments, it allows for several different configurations and capabilities, including hand actuated steering and braking and integrated handlebar steering;
The incorporated ridges on the braking surfaces facilitate deployment, increase water flow impingement, and increase steering and braking performance characteristics;
Integrated handlebar steering provides a highly-simplified means of enhancing a PWC's performance characteristics;
It offers the potential to increase the safety factor of PWC in general.
Employing common levers, cables and fittings reduce the cost of manufacture, ownership, and increases user familiarity for those versed in the art.
The above description contains many specifics, which should not be construed as limiting the scope of the invention but as merely providing illustrations of some presently preferred embodiments of this invention. For example, the hand levers can take other shapes or forms, the actuating mechanism can be modified, shortened or lengthened, and the paddles may take other shapes and sizes including multiple surfaces.
Thus the scope of this invention should be determined by the claims herein and their legal equivalents, rather than by the examples given herein. | A braking and control mechanism for personal watercraft as described herein comprising a means for activation, by single lever FIG. 2 , integrated into existing art steering assembly FIG. 12 , a means for applying mechanical advantage from the cable assembly mechanism to the brake surface mechanisms, and a plurality of said brake surface mechanisms incorporating means for increasing deployment leverage and water flow impingement, said brake mechanisms providing a means to steer and slow the watercraft when deployed by individually or connectedly pivotally rotating from the watercraft ride plate into the water, thereby causing drag and rearward force on the watercraft. | 1 |
TECHNICAL FIELD
The present invention relates generally to wire dispensers, and more particularly to dispensers for spooled electrical wire.
BACKGROUND OF THE INVENTION
The electrical wire normally used in commercial and industrial construction is of various types, differing in gauge, number of conductors, color and composition of insulation. Such wire is most commonly supplied in coiled form and quite often on spools. The present invention relates to a device for facilitating the transport of spooled electrical wire from one location to another, and for dispensing the wire at the locations.
Various types of spooled wire dispensers have been commercialized. Some have wheels, to render them more transportable and suitable for larger or more spools; some do not. For present purposes, a wheeled wire dispenser will hereinafter be called a "cart," whereas an unwheeled wire dispenser will hereinafter be called a "caddy." The present invention relates primarily, though not exclusively, to a wire "cart."
Spooled wire dispensers, whether they be carts or caddies, typically include a skeletal frame connected to which are "spool bars" which actually carry the spools. The spool bars are generally horizontal on most spooled wire dispensers. The skeletal frames of typical spooled wire dispensers either include a pair of vertical "uprights" with spool bars spanning horizontally therebetween (the "split upright" type); or a single vertical "central upright" with horizontal spool bars extending outwardly therefrom.
There are several problems with prior spooled wire dispensers. One problem with many cart-type dispensers relates to their handles. A typical spool cart includes a handle attached to its skeletal frame, the handle extending outwardly and/or upwardly from the frame to provide greater leverage for ease in maneuvering the cart. The handle is typically rigidly attached to the skeletal frame, which makes for a strong frame/handle assembly but which also makes the cart more unwieldy when trying to pack or unpack it in or from a vehicle for transport to a new job site. Some prior dispenser handles could be disconnected from the cart frame, but when the handle was so disconnected it could of course be misplaced or damaged.
Another common problem with prior spooled wire dispensers of the central upright type (as distinguished from the split upright type) is retaining the spools on the spool bars. The central upright type of frame is thought to be advantageous, at least for spools in the small to medium size range, in that the spools can be mounted to or dismounted from the spool bars of a "central upright" type dispenser without having to disconnect the spool bars from the upright. The spools can simply be slipped over the free ends of the spool bars. But there must be some way to prevent the spools from falling off the "free ends" of the centrally-supported spool bars. Attempted solutions to this problem include tipping the spool bars slightly such that they angle upwardly, thus employing gravity to retain the spools. The problem with this technique is that it makes the dispenser more expensive (because of the additional cost associated with separately connecting each spool bar at an angle), and also there is the problem of the additional friction between the inner surfaces of the spools and the central frame caused by rubbing between the inner surface of the spool and the central frame. By tilting the spool bars the spools tend to ride in on and rub against the central frame, thus making it more difficult to rotate the spools to dispense wire.
Another common way to retain the spools on centrally-supported spool bars is to use something in the nature of a cotter pin or spring clip. The spring clip technique is clearly less expensive than the inclined spool bar approach discussed immediately above, and inherently there is less friction between the spools and the frame. The problem with prior spring clip designs, however, is that the clips had to be completely disconnected from the free ends of the spool bars in order to slide the spools on or off. The spring clips, once removed, could very easily be misplaced.
Additional problems with prior spooled wire dispensers include the fact that some of them could only dispense wire in one orientation, with the frame horizontal or vertical, but not both; many were bulky and hard to handle and many prior spooled wire dispensers could not hold an adequate number of spools given the wide variety of wire that may be needed at any one job site.
The present invention is directed toward a spooled wire dispenser which addresses the problems discussed above. More particularly, the spooled wire dispenser of the present invention is a "central upright" type dispenser preferably including (i) an improved handle, which can facilitate movement of the dispenser but can also be folded out of the way when it isn't needed; (ii) improved clips at the "free ends" of the spool bars, wherein the clips needn't be completely removed from the spool bars in order to slide spools thereover; (iii) a design which allows dispensing of wire with the frame in either a horizontal or a vertical position; and (iv) an arrangement of spool bars on the central frame of the dispenser which accommodates a wide variety of spool sizes.
SUMMARY OF THE INVENTION
One embodiment of the invention is a spooled wire dispenser including a central frame; a plurality of spool bars supported by and extending outwardly from the central frame; and spool retainer means mounted on the free end of each spool bar, each spool retainer means having a "blocking mode" and an "unblocking mode." When the spool retainer means is in its "blocking mode," wire spools cannot freely slide over the free end of the spool bar, and when the spool retainer means is in its "unblocking mode," a wire spool can freely slide over the free end of the spool bar. In both modes (i.e., blocking and unblocking), the spool retainer means remains operatively connected to the free end of the spool bar.
In a preferred embodiment, when a spool retainer means is in its blocking mode it extends substantially beyond the outer periphery of the free end of the spool bar.
Preferably, the spool retainer means includes an elongate element which is substantially parallel to the spool bar when the spool retainer means is in its unblocking mode, and substantially perpendicular to the spool bar when the spool retainer means is in its blocking mode.
Preferably, the free end of each spool bar forms a notch for receiving the elongate element; and the free end of the spool bar also includes a pin extending across the notch, wherein the spool retainer elongate element is received by the notch and in turn receives the pin.
In a preferred embodiment, one or more resilient elements are used to center the elongate element in the notch discussed above.
Another aspect of the present invention is an elongate handle for a spooled wire dispenser cart, wherein the handle is pivotable and has an extended position whereby significant leverage can be applied to the frame during transport, and a folded position whereby the handle folds compactly against the frame of the cart.
In a preferred embodiment, the spooled wire dispenser cart has two wire dispensing modes, vertical and horizontal, wherein in the horizontal dispensing mode the free end of the handle engages the floor and operatively supports one end of the frame of the cart. The other end of the cart is supported by one or more wheels.
Still another aspect of the present invention is the construction of the central frame of the cart using first and second spaced, substantially parallel, elongate members; and a plurality of spaced spool bars supported by and extending outwardly from the parallel elongate members of the central frame, wherein the spool bars are in a staggered pattern whereby a large number and variety of spools can be accommodated.
Additional aspects, features and advantages of the present invention will be apparent in view of the detailed description of the invention, below, which refers to the appended Drawing, the various figures of which are briefly described below.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of a preferred spooled wire dispenser cart according to the present invention, the cart being in its "vertical dispensing mode";
FIG. 2 is an enlarged, partial view of the wire dispenser cart of FIG. 1, showing extended and folded positions of a preferred handle assembly;
FIG. 3 is a side elevational view of the wire cart of FIG. 1, showing the cart in its "horizontal dispensing model";
FIG. 4 is a perspective view of the wire cart of FIG. 1, again showing the cart in its "vertical dispensing mode" and showing the cart loaded with spools;
FIG. 5 is a side elevational view of a preferred spool retainer assembly for the wire dispenser cart of FIG. 1;
FIG. 6 is an end elevational view of the spool retainer assembly of the cart shown in FIG. 1;
FIG. 7 is a side elevational view of the spool retainer assembly of FIG. 6;
FIG. 8 is a top plan view of the spool retainer assembly of FIG. 6, with an "elongate element" thereof in its blocking position;
FIG. 9 is a side elevational view of the spool retainer assembly of FIG. 6, with the "elongate element" parallel to the spool bar and in its fully extended position relative to same; and
FIG. 10 is a side view of the spool retainer assembly of FIG. 6 in its normal "unblocking mode," with the elongate element inserted into the end of the spool bar.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the Drawing, wherein like reference numerals designate like parts and assemblies throughout the several views, FIG. 1 shows a perspective view of a preferred electrical wire dispensing cart 20 according to the invention. Cart 20 includes a substantially rectangular central frame 22 made up of a pair of spaced, parallel, relatively long members 24; and a pair of spaced, parallel, relatively short members 26, wherein the long members 24 are substantially perpendicular to the short members 26. When cart 20 is in its vertical dispensing mode, as shown in FIG. 1, long members 24 are substantially vertical; and when cart 20 is in its horizontal dispensing mode, as shown in FIG. 3, long members 24 are substantially horizontal. Long members 24 and short members 26 combine to form the rectangular central frame 22, the frame 22 having four corners which have been designated 28, 30, 32 and 34 in the Drawing. Frame 22 is preferably made from one inch square steel tubing which is cut to the appropriate lengths and welded.
With reference to FIG. 1, connected to the lower rear corner 30 of frame 22 is a centrally-supported transverse wheel strut 36, the opposite ends of which carry free rolling wheels 38 to facilitate transport of the cart 20. The preferred length of the wheel strut 36 is about 18 inches. Strut 36 is also preferably made of one inch square steel tubing. The preferred diameter of wheels 38 is about 8 inches.
Still with reference to FIG. 1, connected to the lower front corner 28 of frame 22 is a T-shaped front stabilizer 40 which supports the front end of the frame 22 when the frame 22 is in its vertical dispensing mode (as shown in FIGS. 1 and 4). It should be noted that T-shaped front stabilizer 40 extends vertically downwardly from the lower short member 26 of the frame 22 a distance roughly equal to the radius of wheels 38, so that the frame 22 will sit with the long members 24 in a substantially vertical orientation when the cart 20 is in its "vertical dispensing mode." The vertical part of the "T" is preferably simply a downward extension of front frame member 24. Connected to the lower end of the vertical part of the "T" is a horizontal member 42. Each end of the horizontal member 42 of front stabilizer 40, which is preferably made of 1/2 inch heavy-wall pipe, carries a rubber cap 44 to further enhance stability.
Pivotably attached to the upper rear corner 34 of frame 22 is a handle 46. With particular reference to FIG. 2, handle 46 extends upwardly and rearwardly from frame 22 such that it forms roughly a 45° angle relative to the short frame member 26. A secured end 48 of handle 46 is pivotably attached to the upper rear corner 34 of frame 22. Handle 46 includes an elongate element 50 preferably comprised of one inch square steel tubing. At the secured end 48 of handle 46 element 50 carries a pair of horizontally-spaced vertically-oriented steel "tines" 52 which extend substantially perpendicular to element 50. Holes are drilled in tines 52 so that they can accept a bolt or pin 54. The upper rear corner 34 of frame 22 is similarly drilled. Tines 52 sandwich the upper rear frame corner 34 and bolt 54 extends through the tines 52 and through the upper rear corner 34 of frame 22 and as a result the handle 46 can be readily pivoted relative to frame 22.
It should be noted that the handle 46 has two positions, an extended position as shown in FIG. 2 in phantom; and a folded position as shown in FIG. 2 in solid lines. The secured end 48 of handle 46 is cut at a 45° angle so that it rests flush against the upper short member 26 when the handle 46 is in its extended position as shown in FIG. 2 in phantom. Extending from the lower tip of element 50 is a short flat flange 56 which rests flush against upper short member 26 when handle 46 is in its extended position. A simple latch 58 is pivotally connected to the top surface of short member 26, and latch 58 can be pivoted so that a portion of it extends over flange 56 to lock handle 46 in its extended position. Latch 58 can also be pivoted such that it does not extend over flange 56, in which case handle 46 can be pivoted and folded to rest against the back surface of rearwardmost long member 24 (as shown in FIG. 2 in solid line).
The free end of handle elongate element 50 can include a rubber hand grip 60 for ease of use.
Referring again to FIG. 1, extending outwardly from central frame 22 is a plurality of spool bars 62. Each spool bar 62 is generally horizontal, and includes a secured end 64 attached to central frame 22 and a free end 66 opposite thereto. In a preferred embodiment, spool bars 62 are made of one-half inch stainless steel pipe (having an outside diameter of approximately 0.675 inch), and a given piece of stainless steel pipe 68 actually forms a pair of spool bars 62, one on each side of central frame 22. That is, in a preferred embodiment long members 24 of frame 22 are drilled through to receive the stainless steel pipe 68 so that two spool bars 62 can in effect be created from a single piece of stainless steel pipe 68. The pipe 68 which forms spool bars 62 is secured to central frame 22 using a set screw or bolt 70 which is received by a female threaded hole in the central frame 22. The through holes in the central frame 22, for the stainless steel pipe 68 which comprises spool bars 62, are preferably 0.687 inch. The one-half inch stainless steel pipe 68 accommodates virtually all known wire spools. Each spool bar 62 extends outwardly from frame 22 about 10.5 inches.
The spool bars 62 are preferably staggered as shown in FIGS. 1 and 4 so as to accommodate a wide variety of spools. A preferred centerline distance from spool bar 62 to spool bar 62 along a given frame long member 24 is 7 inches. Referring to FIG. 1, the rear or lower long member 24 (depending on whether cart 20 is in its vertical dispensing mode or horizontal dispensing mode, respectively) has its first spool bar 62 spaced at a distance of about 4 inches from the outer periphery of wheel 38 and there are two additional spool bars 62 spaced above the lower spool bar 62 (when cart 20 is in its vertical mode, as shown in FIG. 1). By contrast "front" long member 24 (with reference to FIG. 1) carries eight spool bars 62, four on each side of "front" long member 24, with the "lowermost" spool bars 62 roughly at a distance of 7.5 inches from the centerline of the horizontal member 42 of front stabilizer 40. Three additional sets of spool bars 62 are spaced above these lower spool bars 62 on "front" long member 24. Thus, in the preferred embodiment there are fourteen spool bars in all, eight on the "front" long member 24, and six on the "rear" long member 24. As noted above, the spool bars 62 are preferably staggered such that a given set of spool bars 62 on the "front" long member 24 is roughly mid-way between a pair of "vertically-adjacent" spool bars 62 on the "rear" long member 24. This staggered arrangement accommodates the largest possible number of spools, and the largest diameter spools, as well. Alternate spool bars may be unbolted and removed to accommodate larger diameter spools.
At the free end 66 of each spool bar 62 is a "spool retainer means" 74. The purpose of the "spool retainer means" is to selectively block the free end 66 of the corresponding spool bar 62 so as to selectively allow a spool to slide thereover. Thus, when all of the wire spools are in place, the "spool retainer means" 74 can be put in their "blocking modes" so that the spools cannot freely slide over the free ends 66 of the spool bars 62 and therefore the spools are retained thereon. When it is necessary to mount a spool on a spool bar 62, or dismount a spool from same, it is simply necessary to manipulate the "spool retainer means" 74 to put it into its "unblocking mode."
With reference to FIGS. 5-10, each "spool retainer means" 74 preferably includes an elongate B-shaped element 76 which fits into a notch 78 formed in the spool bar free end 66. With particular reference to FIG. 5 each B-shaped elongate element 76 is formed from a single piece of steel wire, rod or the like which is bent or formed roughly into the shape of a capital B. The upper "lobe" 80 of the B-shaped elongate element 76 is shorter than the lower "lobe" 82 of the elongate element 76. Each "lobe" 80 or 82 has a hollow interior formed by the steel wire or rod being looped around to form a substantially rectangular shape as shown in FIG. 5. The thickness of the steel wire, rod, etc., must be narrower than the spool bars they are intended to be used on.
Extending across each notch 78 in the spool bar free ends 66 is a pin 84. Pin 84, preferably a roll pin, also extends through the interior of the lower lobe 82 of elongate element 76. In a preferred embodiment, there is also an extension spring 86 wound around pin 84 on each side of elongate element 76 as shown in FIG. 6, an end elevational view of a "spool bar retainer means" 74 in its "blocking mode." More particularly, on each side of elongate element 76, and in engagement therewith, is a flat washer 88 and bearing against each flat washer 88 is an extension spring 86 which also bears against the inner surface of the notch or tubular material of the pipe, for example, which forms the spool bar. In a given retainer means assembly, the extension springs 86 in effect center elongate element 76 in the notch 78 so as to prevent the elongate element 76 from "flopping around" in notch 78, given the fact that the width of notch 78 is greater than the diameter of the wire or rod which forms elongate element 76, to prevent binding. Extension springs 86 are not necessary, but they help maintain a slight tension on elongate element 76 and in so doing create a smoother operation of the mechanism. It should be noted that extension springs 86 could be replaced by rubber inserts or any other type of resilient elements.
FIGS. 6 and 7 show the spool retainer assembly or means 74 in its blocking mode. As can be seen, in this mode elongate element 76 is aligned such that it is substantially perpendicular to the pipe 68. When the elongate element 76 is positioned perpendicular to spool bar pipe 68 it is held firmly between the back edge of notch 78 and the roll pin 84. In order to put the retainer means 74 in its "unblocking mode" it is simply necessary to draw the elongate element 76 upwardly until the bottom of the elongate element lobe 82 touches roll pin 84, at which time elongate element 76 can be pivoted about roll pin 84 until elongate element 76 aligns with spool bar pipe 68, and then pushed partially back into the hollow end of spool bar pipe 68.
With reference to FIGS. 6 and 7, it can be seen that when the "retainer means" is in its "blocking mode," elongate element 76 is preferably extending above the outer periphery of the spool bar roughly the same distance elongate element 76 is extending below the outer periphery of the spool bar. This is possible because the lower lobe 82 of the elongate element "B" is considerably longer than the upper lobe 80 of the "B". This asymmetrical shape of the "B" also helps to keep the elongate element 76 in its blocking position, as shown in FIGS. 6 and 7, even when the cart 22 is being transported or otherwise jostled about. This is because the lower lobe 82 of the "B" is obviously heavier than the upper lobe 80 of the "B" and the greater weight of the lower lobe 82 helps prevent the elongate element 76 from inadvertently jumping out of its blocking position. That is, elongate element 76 is held down such that the upper inner surface of the bottom lobe 82 of the "B" continues to rest on the roll pin 84. It should also be noted that the friction of the spring/washer assembly helps to keep the elongate element from jumping or falling out of the elongate element's intended position.
A preferred embodiment of the invention is described above. Those skilled in the art will recognize that many embodiments are possible within the scope of the invention. Variations and modifications of the various parts and assemblies can certainly be made and still fall within the scope of the invention. For example, standard spring clips could be used in lieu of the preferred "spool retainer means" 74 described above. Thus, the invention is limited only to the apparatus and method recited in the following claims, and equivalents thereof. | A spooled wire dispenser cart (20) including a central frame (22) and a plurality of spaced spool bars (62). At the free end (66) of each spool bar (62) is a "spool retainer" (74). Each spool retainer (74) includes an elongate element (76) which has an "unblocking position" relative to the spool bar (62) wherein wire spools can be freely slid over the free end of the spool bar (62); and a "blocking position" relative to the spool bar (62) such that wire spools are prevented from sliding over the free end of the spool bar. A preferred wire cart (20) also includes a folding handle (46) which has an extended position useful for maneuvering the cart (20), and a folded position wherein handle (46) is compactly folded against the central frame (22) of cart (20). | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention concerns novel tetrazole, acylhydroxylamine, hydroxymethylketone and amide derivatives of unsaturated fatty acids and, where applicable, their pharmaceutically acceptable salts, their use in the prevention and treatment of inflammatory processes, pain and allergic reactions, and pharmaceutical compositions containing these compounds and methods of their preparation.
Arachidonic acid is the biological precursor of such pro-inflammatory agents as prostaglandins and leucotrienes, or the platelet aggregation inducers thromboxanes. Compounds of this invention show selective inhibitory activity on the enzymes involved in the metabolic synthetic pathways of prostaglandins, leucotrienes or thromboxanes. These compounds will be beneficial in the prevention or treatment of inflammatory and painful disorders, such as rheumatoid arthritis, or in the prevention or treatment of disorders of allergic origin, such as bronchospasm in asthma.
2. Related Disclosures
Those compounds closest in structure to those of the present invention are 2-descarboxy-2-(tetrazol-5-yl) prostaglandins disclosed in Dutch Pat. No. NL-7,211,860Q; N-(hydroxyalkyl) aliphatic amides disclosed in Belgium Pat. BE No. 785,292Q; Vitamin F compounds disclosed in French Pat. No. 2,264,522; long-chain fatty acid amides disclosed in French Pat. No. 2,140,369Q; unsaturated fatty acid amides disclosed in British Pat. No. 1,074,693 and 16-24 carbon unsaturated fatty acid amides disclosed in Dutch Pat. Neth. No. 6,604,058; quarternary ammonium hydroxamates are described in U.S. Pat. No. 3,427,316, and N-substituted fatty acid amides as cholesterol lowering agents are described in U.S. Pat. No. 3,995,059.
J.Med.Chem., 12:1184(1975) describes analogs of lysophosphatidylethanolamine which inhibit renin activity. Eicosatetrayn-5,8,11,14-oic acid and its salts and esters are described in Belgium Pat. No. 711,448.
SUMMARY OF THE INVENTION
One aspect of this invention relates to compounds represented by the formulas (1), (2) and (3). ##STR1## and their pharmaceutically acceptable salts wherein
A is C═C or C.tbd.C;
B is C═C or C.tbd.C;
D is C--C, C═C, or C.tbd.C;
E is C--C, C═C, or C.tbd.C;
F is C--C, C═C, or C.tbd.C;
Z is --CH 3 , --CH 2 CH 3 , --CH 2 CH 2 CH 3 , --CH 2 CH 2 CH 2 CH 3 ; and
X is 1-H-tetrazol-5-yl, C(O)NHOH, CONH 2 or C(O)CH 2 OH.
Another aspect of this invention is a method of treating inflammation and allergic reactions in mammals by administering a therapeutically effective amount of a compound of formula (1), (2) or (3), or their pharmaceutically acceptable, non-toxic salts.
Still another aspect of this invention is a pharmaceutical composition containing a suitable pharmaceutical excipient and a compound of formula (1), (2) or (3), or its pharmaceutically acceptable, non-toxic salts.
Lastly, another aspect of this invention is a process for preparing compounds of formulas (1), (2) and (3), and their corresponding pharmaceutically acceptable, non-toxic salts, as discussed below.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
As used herein "1-H-tetrazol-5-yl" means the compound N 4 CH-- wherein the H atom is attached to the tetrazole ring at position number 1 and the 1H-tetrazole ring is attached to the unsaturated aliphatic chain at the 5-position. The numbering of the heterocyclic ring follows the IUPAC numbering system. ##STR2##
As used herein "acylhydroxylamine" represents the radical --C(O)NHOH. Acylhydroxylamines are also referred to as hydroxamic acids.
As used herein "hydroxymethylketone" represents the radical --C(O)CH 2 OH.
As used hereinafter "unsaturated fatty acids" are fatty acids with 3 to 5 double or triple bonds in their carbon chain such as for example arachidonic acid, linolenic acid, eicosatrienoic acid, eicosatriynoic acid and such.
Carbons in fatty acids are numbered according to the IUPAC numbering system as illustrated below. ##STR3##
(Z) is used in its conventional fashion to denote the cis stereochemistry of double bonds and follows the number of the carbon atom from which the double bond emanates.
Classical nomenclature is used to name a compound having a triple bond as -ynyl and double bond as -enyl.
"Pharmaceutically acceptable, non-toxic salts" refers to salts derived from pharmaceutically acceptable, non-toxic inorganic and organic bases.
Exemplary names are given in the "Preferred Embodiment" section of this application.
PREFERRED EMBODIMENTS OF THE INVENTION
One group of preferred compounds of this invention is the compounds of formula (1): ##STR4## wherein X is 1-H-tetrazol-5-yl, C(O)NHOH, C(O)CH 2 OH or CONH 2 , and Z is CH 2 CH 2 CH 3 or CH 2 CH 2 CH 2 CH 3 . Representative compounds of this group are 5-(eicosa-7(Z),13(Z)-diene-4,10-diynyl)-1-H-tetrazole; heneicosa-8(Z),14(Z)-diene-5,11-diynoylhydroxylamine; 1-hydroxydocosa-9(Z),15(Z)-diene-6,12-diyn-2-one; heneicosa-8(Z),14(Z)-diene-5,11-diynamide; docosa-8(Z),14(Z)-diene-5,11-diynamide; 5-(heneicosa-7(Z),13(Z)-diene-4,10-diynyl)-1-H-tetrazole; docosa-8(Z),14(Z)-diene-5,11-diynoylhydroxylamine; 1-hydroxytricosa-9(Z),15(Z)-diene-6,12-diyn-2-one.
Another group of preferred compounds of this invention are compounds of formula (1): ##STR5## wherein X is 1-H-tetrazol-5-yl, C(O)NHOH, C(O)CH 2 OH or CONH 2 and Z is CH 2 CH 2 CH 3 or CH 2 CH 2 CH 2 CH 3 . Representative compounds of this group are 5-(eicosa-7(Z),10(Z),13(Z)-trien-4-ynyl)-1-H-tetrazole; heneicosa-8(Z),11(Z),14(Z)-trien-5-ynoylhydroxylamine; 1-hydroxydocosa-9(Z),12(Z),15(Z)-trien-6-yn-2-one; 5-(heneicosa-7(Z),10(Z),13(Z)-trien-4-ynyl)-1-H-tetrazole; docosa-8(Z),11(Z),14(Z)-trien-5-ynoylhydroxylamine; heneicosa-8(Z),11(Z),14(Z)-trien-5-ynamide; docosa-8(Z),11(Z),14(Z)-trien-5-ynamide; and 1-hydroxytricosa-9(Z),12(Z),15(Z)-trien-6-yn-2-one.
Other preferred compounds are those represented by formula (1) ##STR6## wherein X is 1-H-tetrazol-5-yl, C(O)NHOH, C(O)CH 2 OH or CONH 2 . Compounds representative of this group are 5-(nonadeca-4(Z),7(Z),10(Z),13(Z)-tetraenyl)-1-H-tetrazole; eicosa-5(Z),8(Z),11(Z),14(Z)-tetraenoylhydroxylamine; 1-hydroxyheneicosa-6(Z),9(Z),12(Z),15(Z)-tetraen-2-one and eicosa-5(Z),8(Z),11(Z),14(Z)-tetraenamide.
More preferred compounds of this invention are the compounds of formula (1) ##STR7## wherein X is 1-H-tetrazol-5-yl, C(O)NHOH, C(O)CH 2 OH or CONH 2 . Representative compounds of this group are 5-(nonadeca-4,7,10,13-tetraynyl)-1-H-tetrazole; eicosa-5,8,11,14-tetraynoyl hydroxylamine; 1-hydroxyheneicosa-6,9,12,15-tetrayn-2-one; and eicosa-5,8,11,14-tetraynamide.
Most preferred compounds of this invention are compounds of formula (1) ##STR8## wherein X is 1-H-tetrazol-5-yl, C(O)NHOH, C(O)CH 2 OH or CONH 2 . Compounds representative of this group are 5-(eicosa-4,7,10,13-tetraynyl)-1-H-tetrazole; heneicosa-5,8,11,14-tetraynoylhydroxylamine; 1-hydroxydocosa-6,9,12,15-tetrayn-2-one; and heneicosa-5,8,11,14-tetraynamide.
PREPARATION PROCEDURES
Preparation of fatty acid precursors with various combinations of double and triple bonds is known.
Isolation of twenty carbon eicosa-5(Z),8(Z),11(Z),14(Z)-tetraenoic acid (arachidonic acid) from organic materials is described in J. Biol. Chem., 80, 455, (1928) and is hereby incorporated by reference.
Syntheses of nineteen carbon nonadeca-5(Z),8(Z),11(Z)14(Z)-tetraenoic acid and twenty-one carbon heneicosa-5(Z),8(Z),11(Z),14(Z)-tetraenoic acid are described in Recueil, 87, 461, (1968) and the references herein and are hereby incorporated by reference.
Preparations of octadeca-8(Z),11(Z),14(Z)-trienoic acid, nonadeca-8(Z),11(Z),14(Z)-trienoic acid, heneicosa-8(Z),11(Z),14(Z)-trienoic acid, and docosa-8(Z),11(Z),14(Z)-trienoic acid are described in Recueil, 87, 461, (1968) and the references therein and are hereby incorporated by reference.
Synthesis of octadeca-9,12,15-trienoic acid (linolenic acid) is described in J. Chem. Soc., 4049 (1956) and the references therein and is hereby incorporated by reference.
Eicosa-5,8,11,14-tetraynoic acid preparation is described in J. Chem. Soc., 2771 (1969) and is hereby incorporated by reference.
14,15-Dehydroarachidonic acid (eicosa-5(Z),8(Z),11(Z)-trien-14-ynoic acid) in which the 14,15 double bond is replaced by a triple bond, and its preparation is described in J. Am. Chem. Soc., 104, 1750 (1982) and the references therein, and is hereby incorporated by reference.
5,6-,8,9-,11,12-Dehydroarachidonic acids and their syntheses are described in J. Am. Chem. Soc., 104, 1952 (1982) and in Tetrahedron Letters, 23, 1651, (1982) and the references therein and is hereby incorporated by reference.
Eicosa-4(Z),8(Z),11(Z),14(Z)-tetraenoic acid; eicosa 5(Z),8(Z),11(Z),14(Z)-tetraenoic acid; eicosa-8(Z),11(Z),14(Z),18(Z)-tetraenoic acid; octadeca-5(Z),8(Z),11(Z),14(Z)-tetraenoic acid; docosa-5(Z),8(Z),11(Z),14(Z)-tetraenoic acid; nonadeca-4(Z),7(Z),10(Z),13(Z)-tetraenoic acid; eicosa-4,8,11,14-tetraynoic acid; octadeca-5,8,11,14-tetraynoic acid and their preparations are described in Recueil, 90, 943 (1971) and the references therein, and are hereby incorporated by reference.
Eicosa-8(Z),11(Z),14(Z)-trienoic acid, octadeca-6(Z),9(Z),12(Z)trienoic acid, nonadeca-8(Z),11(Z),14(Z)-trien-5-ynoic acid and their preparations are described in Recueil 94, 262 (1975) and the references therein and are hereby incorporated by reference.
Nonadecatrienoic acid, octadecatrienoic acid, and other substituted trienoic acids are described in Recueil, 94, 269 (1975) and Recueil, 87, 461 (1968) and the references therein, and are hereby incorporated by reference.
Synthesis of arachidonic acid and related higher unsaturated compounds are described in Recueil, 82, 1015 (1963) and the references therein and is hereby incorporated by reference.
The syntheses of naturally-occuring polyunsaturated fatty acids are described in Progress in the Chemistry of Fats and Other Lipids, 9(2), 119-157 (1966) Pergamon Press, Oxford, Publ., and in the references therein and are hereby incorporated by reference.
The syntheses of unsaturated fatty acids which are not specifically described in the references above may be accomplished by using the above described procedures but starting with appropriate different precursors of fatty acids.
Compounds of formula (1), (2) and (3) wherein B and F are C.tbd.C; A and D are C═C, E is C--C, and X is COOH, which are intermediates in the synthesis of compounds of formula (1), (2), and (3), wherein B and F are C.tbd.C, A and D are C═C, E is C--C, and X is 1-H-tetrazol-5-yl, C(O)NHOH; C(O)CH 2 OH, and CONH 2 are made by reacting together a bis(halomagnesium) salt, preferably the bis(bromomagnesium) salt, of hex-5-ynoic acid, hept-6-ynoic acid, or pent-4-ynoic acid, with a 1-halo, preferably a 1-bromoalka-2,8-dien-5-yne. The reaction is conducted in an ethereal solvent, preferably tetrahydrofuran, at a temperature of from 0° C. to 65° C., preferably at 65° C., for from 1 to 72 hours, preferably about 24 hours. From 1 to 3, preferably 2 moles, of the acetylenic acid are used for each mole of the 1-haloalka-2,8-dien-5-yne. The reaction is conducted in the presence of a catalytic amount of a cuprous halide or cyanide, preferably cuprous chloride. The 1-haloalka-2,8-dien-5-ynes which are employed in the reaction are made from the corresponding 1-hydroxyalka-2,8-dien-5-ynes, by reaction with halogenating reagents such as triphenylphosphine/carbon tetrahalide, phosphorus trihalides, or triphenylphosphine/cyanogen bromide, preferably the latter. The reaction is conducted at from 0° C. to 50° C., preferably about 25° C., for from 1 to 24 hours, preferably about 4 hours, in an inert organic solvent, preferably methylene chloride. The halogenating reagent and the alcohol are present in equimolar amounts. The 1-hydroxyalka-2,8-dien-5-ynes are prepared from the corresponding 1-(tetrahydropyranyloxy)-alka-2,8-dien-5-ynes by treatment with an acid such as acetic acid, sulphuric acid, or p-toluenesulphonic acid, preferably the latter, in a water-miscible organic solvent, such as tetrahydrofuran, ethanol or methanol, preferably the latter, optionally in the presence of from 1% to 40%, preferably 5%, by volume, of water. The reaction is conducted at from 0° C. to 50° C., preferably about 25° C., for from 1/2 to 12 hours, preferably 2 hours. The 1-(tetrahydropyranyloxy)alka-2,8-dien-5-ynes are prepared by the Wittig reaction between the ylid generated from 1-(triphenylphosphonio)-alk-6-en-3-yne halides, for example 1-(triphenylphosphonio)-dodec-6-en-3-yne bromide, the preparation of which is described in J. Am. Chem. Soc., 104, 1752 (1982), and 2-(tetrahydropyranyloxy)acetaldehyde, the preparation of which is described in Chem. Pharm. Bull., 11, 188 (1963). The ylid is generated by reaction between the phosphonium halide and an equimolar amount of a strong base, for example, sodium hydride, phenyllithium or butyllithium, preferably butyllithium, in a solvent such as dimethylsulphoxide or tetrahydrofuran, preferably the latter, containing from 0% to 25%, preferably 10% by volume, of hexamethylphosphoric triamide at a temperature of from -100° C. to 25° C., preferably -78° C., for from half to 6 hours, preferably 1 hour. The 2-(tetrahydropyranyloxy)acetaldehyde and the phosphonium salt are used in equimolar amounts.
The 1-(tetrahydrofuranyloxy)-alka-2,8-dien-5-ynes are also prepared by the coupling reaction between a 1-haloalk-2-ene, for example, 1-bromooct-2-ene, the preparation of which is described in J. Chem. Soc., 3868 (1957) and 1-(tetrahydropyranyloxy)hex-2-en-5-yne. The coupling reaction is conducted in an aqueous or aqueous alcoholic solution, at a temperature of from 0° C. to about 100° C., optionally in the presence of a cuprous salt, for example, cuprous chloride, for from 1 to 24 hours. 1-(Tetrahydropyranyloxy)hex-2-en-5-yne is obtained by the acid-catalyzed reaction between dihydropyran and hex-2-en-5-yn-1-ol, the preparation of which is described in Bull. Soc. Chem. France, 2105 (1963). The reaction is conducted either without solvent or in the presence of an organic solvent such as ether or methylene chloride, in the presence of an acid catalyst such as sulphuric acid, hydrochloric acid or phosphorus oxychloride.
Compounds wherein X is 1-H-tetrazol-5-yl and CONH 2 are prepared according to the Reaction Scheme 1.
REACTION SCHEME 1 ##STR9##
R-COOH is an unsaturated fatty acid of the formula (1), (2) or (3) wherein
A is C═C or C.tbd.C;
B is C═C or C.tbd.C;
D is C--C, C═C, or C.tbd.C;
E is C--C, C═C, or C.tbd.C;
F is C--C, C═C, or C.tbd.C; and
X is COOH.
In the following description the Roman numerals in parentheses show the steps in the Reaction Scheme.
Preparation of tetrazole derivatives of various unsaturated fatty acids of 18-22 carbon chain begins with the reaction of an appropriate unsaturated fatty acid of formula (1), (2) or (3), X is COOH, for example arachidonic acid, with carbonyldiimidazole in the molar ratio of 1:1 in an aprotic organic solvent, preferably dichloromethane, for a period of 1-7 hours, preferably 4 hours. Then the product of the reaction is reacted with a large excess of ammonium hydroxide for 24-64 hours, preferably for 48 hours. Eicosa-5(Z),8(Z),11(Z),14(Z)-tetraenamide (II) or any other unsaturated fatty acid amide (depending on the initially used unsaturated fatty acid) is obtained using separation procedures known in the art.
To a solution of compound (II) in a basic organic solvent, preferably pyridine, is added an organic sulphonyl halide, preferably p-toluenesulphonyl chloride in a molar ratio 1:1. The mixture is reacted for 12-48 hours, preferably 24 hours, and the solution is poured into water. Eicosa 5(Z),8(Z),11(Z),14(Z) tetraenenitrile (III) or any other fatty acid nitrile, is extracted from the aqueous phase with an organic solvent, preferably ethyl ether, and the extract is purified by procedures known in the art.
Compound (III) is then reacted with an excess, preferably 3 moles, of an alkali metal azide, preferably sodium azide, and an excess, preferably 3 moles, of an ammonium halide, preferably ammonium chloride, in an aprotic polar solvent, preferably dimethylformamide, at a temperature of 80° C. to 120° C., preferably 100° C., for 16 to 48 hours, preferably 24 hours optionally in the presence of a Lewis acid such as, for example, boron trifluoride.
The product, 5-(nonadeca-4(Z),7(Z),10(Z),13(Z) tetraenyl)-1-H-tetrazole (IV) is then isolated by procedures known in the art.
Tetrazole derivatives of other unsaturated fatty acids are obtained by the same procedure wherein one of those unsaturated fatty acids described in formulas (1), (2), and (3), wherein X is COOH is used as the starting material.
Preparation of amide derivatives of unsaturated fatty acids can be alternately effected by first converting the acid into an activated derivative such as, for example, an acyl halide, an anhydride, a mixed anhydride, an alkyl ester, a substituted or unsubstituted phenyl ester, a thioalkyl ester, a thiophenyl ester, an acyl imidazole, and the like. The activated derivative is then reacted with ammonia or aqueous ammonia with or without a suitable water-miscible or immiscible organic solvent, for example, methanol, ethanol, dichloromethane, and the like, so as to produce the amide. The reaction is conducted at from -30° C. to the boiling point of the solvent or solvent mixture used, for from 1 to 96 hours. Alternatively, the amide can be made by heating together the unsaturated fatty acid and ammonia, or by heating the ammonium salt of the unsaturated fatty acid. The reaction is conducted either in the absence of a solvent, or in the presence of a solvent such as, for example, toluene, at a temperature of from 100° C. to 300° C., for from 1 to 12 hours. Alternatively, the amide can be obtained by hydrolysis of the nitrile of an unsaturated fatty acid, using either inorganic or organic acids or bases, such as, for example, hydrochloric acid, sulphuric acid, p-toluenesulphonic acid, sodium hydroxide, potassium carbonate, or tetrabutylammonium hydroxide and the like. The reaction is conducted in water optionally containing from 1% to 95% of a cosolvent such as, for example, methanol, acetic acid or diglyme, at a temperature of from 0° C. to the boiling point of the solvent used, for from 1 to 96 hours. Such procedures are well known to those skilled in the art and are described, for example, in Synthetic Organic Chemistry, John Wiley and Sons, Publ., New York, 565-590 (1953) and Compendium of Organic Synthetic Methods, Vol. 1, Wiley-Interscience, New York, 203-230 (1971).
Tetrazole derivatives of unsaturated fatty acids can alternately be prepared by the reaction between an iminoether, RC(═NH)Oalkyl, (where alkyl is C1-C6) derivative of an unsaturated fatty acid, and hydrazoic acid as described in German Pat. No. 521870. The iminoether derivative is obtained by treatment of a nitrile derivative of an unsaturated fatty acid with an alkanol (C1-C6) and a strong acid such as, for example, hydrochloric acid or p-toluenesulphonic acid. The reaction between the iminoether and hydrazoic acid is conducted in the presence of a solvent such as, for example, chloroform or dimethylformamide, at from 0° C. to 120° C., for from 1 to 72 hours. Tetrazole derivatives can also be obtained by the reaction between an amidine derivative of an unsaturated fatty acid, prepared, for example, from the nitrile derivative of an unsaturated fatty acid, as described in Synthetic Organic Chemistry, John Wiley and Sons, Publ., New York, 635 (1953) and nitrous acid, as described in Annalen, 263, 96 (1981), and 208, 91 (1897). The reaction is conducted in water or a mixture of water and a suitable organic solvent such as, for example, methanol or dioxan, at from 0° C. to 100° C., for from 1 to 24 hours.
Compounds wherein X is C(O)CH 2 OH are prepared from an appropriate unsaturated fatty acid described above according to the procedure of Reaction Scheme 2.
REACTION SCHEME 2 ##STR10##
R--COOH is an unsaturated fatty acid of the formula (1), (2) or (3) wherein
A is C═C or C.tbd.C;
B is C═C or C.tbd.C;
D is C--C, C═C, or C.tbd.C;
E is C--C, C═C, or C.tbd.C;
F is C--C, C═C, or C.tbd.C; and
X is COOH.
Preparation of hydroxymethylketone derivatives (VIII) of various unsaturated fatty acids of 18-22 carbon atoms begins with reacting an appropriate unsaturated fatty acid (V), for example arachidonic acid, with a thionyl or phosphoryl halide or a phosphorus pentahalide, preferably thionyl chloride, dissolved in an inert organic solvent, preferably benzene, containing a trace of a tertiary organic amide, preferably dimethylformamide. The mixture is reacted for 8-32 hours, preferably for 16 hours, at from 0° C. to 25° C., then evaporated to dryness. The residue, the acid chloride (VI), is dissolved in an inert organic solvent, preferably ethyl ether. The solution is cooled to -5° C. to 5° C., preferably to 0° C., and an excess of a solution of diazomethane in an ethereal solvent, preferably diethyl ether, is added. The mixture is allowed to react for 1 to 5 hours, preferably 2 hours, then evaporated to dryness, and the residue, the diazoketone (VII), is dissolved in a water miscible ether, preferably tetrahydrofuran. To the solution is added an aqueous solution of a strong acid, preferably trifluoroacetic acid. The mixture is left to react for 2 to 8 hours, preferably 4 hours, and the target compound (VIII) is then isolated and purified by means known in the art.
Hydroxymethylketone derivatives of unsaturated fatty acids can also be prepared by the reaction of an acyl halide, an anhydride or a mixed anhydride derived from an unsaturated fatty acid, and an alkoxy or alkylthio substituted silylated ketene acetal, followed by decarboxylation of the intermediate product, as described in J. Org. Chem., 25, 4617 (1979). The reaction is performed either with or without a suitable organic solvent such as, for example, toluene or diphenyl ether and either with or without the addition of a Lewis acid catalyst such as, for example, stannic chloride, at from 0° C. to 150° C., for from 5 minutes to 8 hours. The decarboxylation reaction is conducted in a suitable solvent such as dioxan, in the presence of an aqueous mineral acid such as hydrochloric acid, at from 0° C. to 100° C., for from 10 minutes to 3 hours. Hydroxymethylketone derivatives of unsaturated fatty acids can also be obtained by hydrolysis, using either acid, such as hydrochloric acid, or base, such as potassium hydroxide, of an acyloxymethylketone (RCOCH 2 OCO alkyl), or halomethylketone (RCOCH 2 halo) derivative of an unsaturated fatty acid, where alkyl is C1-C6 and halo is chloro, bromo or iodo. The reaction is conducted in an aqueous or aqueous organic solvent, such as methanol, ethanol and the like, at from 0 C. to 60 C. for from 1 to 24 hours.
Preparation of unsaturated fatty acid derivatives wherein X is C(O)NHOH is illustrated in Reaction Scheme 3.
REACTION SCHEME 3 ##STR11##
R--COOH is an unsaturated fatty acid of the formula (1), (2) or (3) wherein
A is C═C or C.tbd.C;
B is C═C or C.tbd.C;
D is C--C, C═C, or C.tbd.C;
E is C--C, C═C, or C.tbd.C;
F is C--C, C═C, or C.tbd.C; and
X is COOH.
The acylhydroxylamine derivatives (XI) of the unsaturated fatty acids are prepared in two ways. The acid (IX) is either first converted, as described above, into an acid halide, preferably the acid chloride (Xb), or into a lower alkyl ester (Xa), preferably the methyl ester, by treatment either with a solution of hydrogen chloride in the appropriate lower alkanol, preferably methanol, or with a diazoalkane, preferably diazomethane. The acid chloride or the lower alkyl ester, so obtained, is then reacted with an excess of hydroxylamine in an aqueous organic solvent, preferably aqueous methanol, at a pH of between 7 and 10, preferably at pH 9, for from 1/4 to 6 hours, preferably about 1 hour. The acylhydroxylamine product (XI) is then isolated by means known in the art.
Acylhydroxylamines can also be prepared by the reaction between hydroxylamine and an activated derivative of an unsaturated fatty acid such as, for example, an acyl halide, an anhydride, a mixed anhydride, an alkyl ester, a substituted or unsubstituted phenyl ester, a thioalkyl ester, a thiophenyl ester, an acyl imidazole, and the like. The reaction is conducted in an aqueous organic or organic solvent such as, for example, methanol, acetonitrile or acetone, at from 0° C. to the reflux temperature of the solvent, for from 1 to 48 hours. Alternately, acylhydroxylamines can be prepared by acid-catalyzed rearrangement of a primary nitro derivative of an unsaturated fatty acid (RNO 2 ) as described in Chemical Reviews, 32, 395 (1943). The reaction is conducted in an aqueous organic or organic solvent, such as, for example, methanol, ethanol and dioxan, at from 0° C. to 100° C., for from 1 to 24 hours, in the presence of a strong acid such as, for example, sulphuric acid or hydrochloric acid. Acylhydroxylamine derivatives of unsaturated fatty acids can also be obtained by the oxidation of the oxime derivative (RCH═NOH) of an unsaturated fatty aldehyde (RCHO), using, for example, hydrogen peroxide as described in Chemical Reviews, 33, 225 (1943). The reaction is conducted in a solvent such as methanol or dichloromethane and the like, at from 0° C. to 35° C. for from 1 to 6 hours.
Isolation and purification of the compounds and intermediates described herein can be effected, if desired, by any suitable separation or purification procedure such as, for example, filtration, extraction, crystallization, column chromatography, thin-layer chromatography or thick-layer chromatography, or a combination of these procedures. Specific illustrations of suitable separation and isolation procedures can be had by reference to the examples hereinbelow. However, other equivalent separation or isolation procedures could, of course, also be used.
Salts of the compounds of formula (1), (2), or (3) may be interchanged by taking advantage of differential solubilities of the salts, or by treating with the appropriately loaded ion exchange resin.
The salts of acylhydroxylamine or tetrazole derivatives of the compounds of formula (1), (2) or (3) are prepared by treating the acylhydroxylamine or tetrazole compound of formula (1), (2), or (3) with at least one molar equivalent of a pharmaceutically acceptable base. Representative pharmaceutically acceptable bases are sodium hydroxide, potassium hydroxide, ammonium hydroxide, calcium hydroxide, metal alkoxides, for example, sodium methoxide, trimethylamine, lysine, caffeine, and the like. The reaction is conducted in water, alone or in combination with an inert, water-miscible organic solvent, or in a suitable organic solvent such as methanol, ethanol, and the like, at a temperature of from about 0° C. to about 100° C., preferably at room temperature. Typical inert, water-miscible organic solvents include methanol, ethanol, or dioxane. The molar ratios of compounds of Formula (1), (2), or (3) to base used are chosen to provide the ratio desired for any particular salt.
Salts derived from inorganic bases include sodium, potassium, lithium, ammonium, calcium, magnesium, ferrous, zinc, copper, manganous, aluminum, ferric, manganic salts and the like. Particularly preferred are the ammonium, potassium, sodium, calcium and magnesium salts. Salts derived from pharmaceutically acceptable organic non-toxic bases include salts of primary, secondary, and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines and basic ion exchange resins, such as isopropylamine, trimethylamine, diethylamine, triethylamine, tripropylamine, ethanolamine, 2-dimethylaminoethanol, 2-diethylaminoethanol, tromethamine, dicyclohexylamine, lysine, arginine, histidine, caffeine, procaine, hydrabamine, choline, betaine, ethylenediamine, glucosamine, methylglucamine, theobromine, purines, piperazine, piperidine, N-ethylpiperidine, polyamine resins and the like. Particularly preferred organic non-toxic bases are isopropylamine, diethylamine, ethanolamine, tromethamine, dicyclohexylamine, choline and caffeine.
The salt products are also isolated by conventional means. For example, the reaction mixtures may be evaporated to dryness, and the salts can be further purified by conventional methods.
UTILITY AND ADMINISTRATION
The compounds of the present invention are tetrazole, acylhydroxylamine, hydroxymethylketone and amide derivatives of unsaturated fatty acids. These compounds display a spectrum of biological activities affecting the enzymatic processes leading to the in vivo synthesis of certain compounds or agents such as prostaglandins or leukotrienes, or platelet aggregation inducing compounds. The compounds of this invention show selective inhibitory activity on the enzymes involved in the metabolic pathways of prostaglandins or leukotrienes, namely they are selective inhibitors of lipoxygenases and cyclooxygenases.
Because of their biological activities, these compounds are promising agents for prophylactic and/or therapeutic use particularly in the treatment of inflammatory disorders such as, for example, rheumatoid arthritis and osteoarthritis, or in the prevention or treatment of disorders of allergic origin such as, for example, bronchospastic symptoms in asthma. The compounds are also useful for the alleviation of pain.
Administration of the active compounds in the pharmaceutical composition described hereinafter can be via any of the accepted modes of administration for agents which affect inflammation, pain or allergy. These methods include oral, parenteral and otherwise systemic administration, or topical administration. Depending on the intended mode, the composition may be in the form of solid, semi-solid or liquid dosage forms, such as, for example, tablets, suppositories, pills, capsules, powders, liquids, suspension, or the like, preferably in unit dosage forms suitable for single administration of precise dosages. The composition will include a conventional pharmaceutical carrier or excipient and an active compound of formula (1), (2), or (3) and/or the pharmaceutically acceptable salts thereof and, in addition, may include other medicinal agents, pharmaceutical agents, carriers, adjuvants, etc.
The amount of active compound administered will of course, be dependent on the subject being treated, the severity of the affliction, the manner of administration and the judgment of the prescribing physician. However, an effective dosage will be in the range of 0.001-50 mg/kg/day, preferably 0.01-10 mg/kg/day. For an average 70 kg human, this would amount to 0.07-3300 mg per day, or preferably 0.7-700 mg/day.
The novel compounds of this invention may be formulated with suitable pharmaceutical vehicles known in the art to form particularly effective anti-inflammatory, anti-allergic and analgesic compositions. Generally, an effective amount of active ingredient is about 0.001% w/w to about 10% w/w of the total formulated composition. The rest of the formulated composition will be about 90% w/w to about 99.999% w of a suitable excipient.
For solid compositions, conventional non-toxic solid carriers include, for example, pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharin, talcum, cellulose, glucose, sucrose, magnesium carbonate, and the like may be used. The active compound as defined above may be formulated as suppositories using, for example, polyalkylene glycols, for example, propylene glycol, as the carrier. Liquid pharmaceutically administerable compositions can, for example, be prepared by dissolving, dispersing, etc. an active compound as defined above and optional pharmaceutical adjuvants in a carrier, such as, for example, water, saline, aqueous dextrose, glycerol, ethanol, and the like, to thereby form a solution or suspension. If desired, the pharmaceutical composition to be administered may also contain minor amounts of nontoxic auxiliary substances such as wetting or emulsifying agents, pH buffering agents and the like, for example, sodium acetate, sorbitan monolaurate, triethanolamine sodium acetate, triethanolamine oleate, etc. Actual methods of preparing such dosage forms are known, or will be apparent, to those skilled in this art; for example, see Remington's Pharmaceutical Sciences, Mack Publishing Company, Easton, Pa., 15th Edition, 1975. The composition or formulation to be administered will, in any event, contain a quantity of the active compound(s) in an amount effective to alleviate the symptoms of the subject being treated.
For oral administration, a pharmaceutically acceptable, non-toxic composition is formed by the incorporation of any of the normally employed excipients, such as, for example pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharin, talcum, cellulose, glucose, sucrose, magnesium, carbonate, and the like. Such compositions take the form of solutions, suspensions, tablets, pills, capsules, powders, sustained release formulations and the like. Such compositions may contain 10%-95% active ingredient, preferably 25-70%.
Parenteral administration is generally characterized by injection, either subcutaneously, intramuscularly or intravenously. Injectables can be prepared in conventional forms, either as liquid solutions or suspensions, solid forms suitable for solution or suspension in liquid prior to injection, or as emulsions. Suitable excipients are, for example, water, saline, dextrose, glycerol, ethanol or the like. In addition, if desired, the pharmaceutical compositions to be administered may also contain minor amounts of non-toxic auxiliary substances such as wetting or emulsifying agents, pH buffering agents and the like, such as for example, sodium acetate, sorbitan monolaurate, triethanolamine oleate, etc.
A more recently devised approach for parenteral administration employs the implantation of a slow-release or sustained-release system, such that a constant level of dosage is maintained. See, e.g., U.S. Pat. No. 3,710,795.
For systemic administration via suppository, traditional binders and carriers include, e.g. polyalkylene glycols or triglycerides. Such suppositories may be formed from mixtures containing active ingredient in the range of 0.5%-10%; preferably 1-2%.
For aerosol administration, the active ingredient is preferably supplied in finely divided form along with a surfactant and a propellant. Typical percentages of active ingredients are 0.01 to 20% by weight, preferably 0.04 to 1.0%.
Surfactants must, of course, be non-toxic, and preferably soluble in the propellant. Representative of such agents are the esters or partial esters of fatty acids containing from 6 to 22 carbon atoms, such as caproic, octanoic, lauric, palmitic, stearic, linoleic, linolenic, olestearic and oleic acids with an aliphatic polyhydric alcohol or its cyclic anhydride such as, for example, ethylene glycol, glycerol, erythritol, arabitol, mannitol, sorbitol, the hexitol anhydrides derived from sorbitol (the sorbitan esters sold under the trademark "Spans") and the polyoxyethylene and polyoxypropylene derivatives of these esters. Mixed esters, such as mixed or natural glycerides may be employed. The preferred surface-active agents are the oleates or sorbitan, e.g., those sold under the trademarks "Arlacel C" (Sorbitan sesquioleate), "Span 80" (sorbitan monooleate) and "Span 85" (sorbitan trioleate). The surfactant may constitute 0.1-20% by weight of the composition, preferably 0.25-5%.
The balance of the composition is ordinarly propellant. Liquefied propellants are typically gases at ambient conditions, and are condensed under pressure. Among suitable liquefied propellants are the lower alkanes containing up to five carbons, such as butane and propane; and preferably fluorinated or fluorochlorinated alkanes, such as are sold under the trademark "Freon." Mixtures of the above may also be employed.
In producing the aerosol, a container equipped with a suitable valve is filled with the appropriate propellant, containing the finely divided active ingredient and surfactant. The ingredients are thus maintained at an elevated pressure until released by action of the valve.
The following Preparations and Examples serve to illustrate the invention and make the invention enabling. They should not be construed as narrowing it or limiting its scope in any way.
EXAMPLE 1
A. Preparation of 1-(Tetrahydropyranyloxy)-hex-2(Z)-en-5-yne
To a solution of hex-2(Z)-en-5-yn-1-ol (5 g) in methylene chloride (100 ml) at O is added phosphorus oxychloride (0.1 ml) and 5 g of dihydropyran. After 2 hours, the solution is added to saturated aqueous sodium carbonate. The organic solution is dried and evaporated to yield the title compound as an oil.
B. Preparation of 1-(Tetrahydropyranyloxy)-tetradec-2(Z),8(Z)-dien-5-yne
1-Tetrahydropyranyloxy)-hex-2(Z)-en-5-yne (1.8 g) is dissolved in 1:2 aqueous ethanol (25 ml) and to the solution is added cuprous chloride (0.2 g) and sufficient 50% aqueous sodium hydroxide to produce a pH of 9. The mixture is heated to 60 and 1-bromooct-2(Z)-ene (1.9 g) is added over a period of 2 hours, with simultaneous addition of sufficient 50% aqueous sodium hydroxide to maintain a pH of 8-9. After a further 3 hours, the mixture is cooled, diluted with water, and extracted with ether. The extract is washed, dried and evaporated, and the crude product is chromatographed on silica gel, eluting with benzene/triethylamine (300/l), so as to produce the title compound as an oil.
EXAMPLE 2
Preparation of 1-Hydroxytetradeca-2(Z),8(Z)dien-5-yne
p-Toluenesulphonic acid monohydrate (30 mg) was added to a solution of 1-(tetrahydroxypyranyloxy)tetradeca-2(Z),8(Z)-dien-5-yne (1.1 g) in methanol (30 ml). The mixture was kept at 25 C. for 2 hours, then ether and water were added. The organic solution was washed, dried and evaporated to yield the title compound as an oil.
EXAMPLE 3
Preparation of 1-Bromotetradeca-2(Z),8(Z)-dien-5-yne
1-Hydroxytetradeca-2(Z),8(Z)-dien-5-yne (600 mg) was dissolved in methylene chloride (10 ml) and to the solution was added triphenylphosphine (600 mg) and cyanogen bromide (200 mg). After 21/2 hours the methylene chloride was removed under vacuum and the residue was extracted with 10 ml of hexane/ether (10/l;v/v). The solution was filtered through silica gel (2 g) and evaporated to yield the title compound as an oil.
EXAMPLE 4
Preparation of Eicosa-8(Z),14(Z)-diene5,11-diynoic acid
To a solution of hex-5-ynoic acid (448 mg) in tetrahydrofuran (10 ml) was added ethereal ethylmagnesium bromide (2.7 ml of a 3.0 molar solution). The mixture was refluxed for 1 hour, then cuprous chloride (10 mg) and 1-bromotetradeca-2(Z),8(Z)-dien-5-yne (550 mg) were added. The reaction was refluxed for 24 hours, then cooled and dilute hydrochloric acid and ether were added. The organic layer was dried and evaporated, and the residue was chromatographed on silica gel, eluting with hexane/ether/acetic acid, (200/200/1;v/v/v) so as to afford the title compound as an oil.
EXAMPLE 5
Preparation of 5-(Nonadeca-4(Z),7(Z),10(Z),13(z)-tetraenyl)-1-H-tetrazole
A. Preparation of Eicosa-5(Z),8(Z),11(Z),14(Z)-tetraenamide
Carbonyldiimidazole (1.97 g) was added to a solution of eicosa-5(Z),8(Z),11(Z),14(Z)-tetraenoic acid (3.3 g) in dichloromethane (70 ml). After 4 hours concentrated ammonium hydroxide (10 ml) was added and the mixture was stirred vigorously for 48 hours. The organic solution was separated, dried and evaporated to yield the title compound as a solid, m.p.: ca. 35° C.
B. Preparation of Eicosa-5(Z),8(Z),11(Z),14(Z) tetraenenitrile
p-Toluenesulphonyl chloride (1.54 g) was added to a solution of eicosa-5(Z),8(Z),11(Z),14(Z)-tetraenamide (2.4 g) in pyridine (50 ml). After 24 hours, the solution was poured into water. The aqueous solution was extracted with ether, and the extract was washed with dilute hydrochloric acid, dried and evaporated to give the title compound as an oil.
C. Preparation of 5-(Nonadeca-4(Z),7(Z),10(Z),13(Z)tetraenyl-1-H-tetrazole
Eicosa-5(Z),8(Z),11(Z),14(Z)-tetraenenitrile (1.4 g), sodium azide (1.06 g) and ammonium chloride (0.85 g) were heated at 100° C. in dimethylformamide (8 ml) for 23 hours. The solution was cooled and diluted with ether (50 ml). The ethereal solution was washed with water then extracted with dilute aqueous potassium hydroxide. The aqueous extract was acidified with dilute hydrochloric acid, and extracted with ether. The extract was dried and evaporated to afford the title compound as an oil.
EXAMPLE 6
Preparation of Tetrazole Derivatives of Various Unsaturated Fatty Acids
Similarly, by using the procedure of Example 5, Sections A, B and C, but substituting eicosa-5(Z),8(Z),-11(Z),14(Z)-tetraenoic acid with the following starting materials:
eicosa-5,8,11,14-tetraynoic acid;
heneicosa-5(Z),8(Z),11(Z),14(Z)-tetraenoic acid;
heneicosa-5,8,11,14-tetraynoic acid;
nonadeca-5(Z),8(Z),11(Z),14(Z)-tetraenoic acid;
nonadeca-5,8,11,14-tetraynoic acid;
docosa-5(Z),8(Z),11(Z),14(Z)-tetranoic acid;
docosa-5,8,11,14-tetraynoic acid;
eicosa-6,9,12,15-tetraynoic acid;
docosa-6,9,12,15-tetraynoic acid;
eicosa-4,7,10,13-tetraynoic acid;
docosa-4,7,10,11-tetraynoic acid;
docosa-7,10,14,17-tetraynoic acid;
heneicosa-8,11,14,16-tetraynoic acid;
eicosa-5,8,11-triynoic acid;
nonadeca-8,11,14-triynoic acid;
heneicosa-8(Z),14(Z)-diene-5,11-diynoic acid;
heneicosa-8(Z),11(Z),14(Z)-triene-5-ynoic acid; and
heneicosa-5(Z),8(Z),14(Z)-triene-11-ynoic acid;
there are obtained respectively:
5-(nonadeca-4,7,10,13-tetraynyl)-1-H-tetrazole;
5-(eicosa-4(Z),7(Z),10(Z),13(Z)-tetraenyl)-1-H-tetrazole;
5-(eicosa-4,7,10,13-tetraynyl)-1-H-tetrazole;
5-(octadeca-4(Z),7(Z),10(Z),13(Z)-tetraenyl)-1H-tetrazole;
5-(octadeca-4,7,10,13-tetraynyl)-1-H-tetrazole;
5-(heneicosa-4(Z),7(Z),10(Z),13(Z)-tetraenyl)-1-H-tetrazole;
5-(heneicosa-4,7,10,13-tetraynyl)-1-H-tetrazole;
5-(nonadeca-5,8,11,14-tetraynyl)-1-H-tetrazole;
5-(heneicosa-5,8,11,14-tetraynyl)-1-H-tetrazole;
5-(nonadeca-3,6,9,12-tetraynyl)-1-H-tetrazole;
5-(heneicosa-3,6,9,12-tetraynyl)-1-H-tetrazole;
5-(heneicosa-6,9,13,16-tetraynyl)-1-H-tetrazole;
5-(eicosa-7,10,13,16-tetraynyl)-1-H-tetrazole;
5-(nonadeca-4,7,10-triynyl)-1-tetrazole;
5-(octadeca-7,10,13-triynyl)1-H-tetrazole;
5-(eicosa-7(Z),13(Z)-diene-4,10-diynyl)-1-H-tetrazole;
5-(eicosa-7(Z),10(Z),13(Z)-trien-4-ynyl)-1-H-tetrazole; and
5-(eicosa-4(Z),7(Z),13(Z)-trien-10-ynyl)-1-H-tetrazole.
EXAMPLE 7
Preparation of Eicosa-5(Z),8(Z),11(Z),14(Z)-tetraenoylhydroxylamine
Hydroxylamine hydrochloride (0.95 g) was dissolved in water (2.1 ml) and methanol (1.65 ml) and 10N aqueous sodium hydroxide (2.7 ml ) were added. The resultant solution was added to a solution of methyl eicosa-5(Z),8(Z),11(Z),14(Z)-tetraenoate (1.22 g) in methanol (21 ml). After 1 hour the mixture was acidified to pH 5 with hydrochloric acid, and then extracted with ether. The extract was dried and evaporated and the residue was chromatographed on silica gel, eluting with methylene chloride/methanol/ammonium hydroxide (40/5/0.3;v/v/v), to afford the title compound as an oil.
EXAMPLE 8
Preparation of Acylhydroxylamine Derivatives of Various Unsaturated Fatty Acids
Similarly, by using the procedure of Example 7 but substituting methyl eicosa-5(Z),8(Z),11(Z),14(Z)-tetraenoate with the following starting materials;
methyl heneicosa-5(Z),8(Z),11(Z),14(Z)-tetraenoate;
methyl nonadeca-5(Z),8(Z),11(Z),14(Z)-tetraenoate;
methyl docosa-5(Z),8(Z),11(Z),14(Z)-tetraenoate;
methyl heneicosa-8(Z),14(Z)-diene-5,11-diynoate;
methyl heneicosa-8(Z),11(Z),14(Z)-trien-5-ynoate; and
methyl heneicosa-5(Z),8(Z),14(Z)-trien-11-ynoate;
there are obtained, respectively:
heneicosa-5(Z),8(Z),11(Z),14(Z)-tetraenoyl hydroxylamine;
nonadeca-5(Z),8(Z),11(Z),14(Z)-tetraenoyl hydroxylamine;
docosa-5(Z),8(Z),11(Z),14(Z)-tetraenoyl hydroxylamine;
heneicosa-8(Z),14(Z)-diene-5,11-diynoylhydroxylamine;
heneicosa-8(Z),11(Z),14(Z)-trien-5-ynoyl-hydroxylamine; and
heneicosa-5(Z),8(Z),14(Z)-trien-11-ynoyl-hydroxylamine.
EXAMPLE 9
Preparation of Heneicosa-5,8,11,14-tetraynoylhydroxylamine
Heneicosa-5,8,11,14-tetraynoic acid (130 mg) was dissolved in methylene chloride (3 ml) and a solution of thionyl chloride (104 mg) and dimethylformamide (5 mg) in methylene chloride (2.6 ml) was added. After 3 hours at 25° C., the solution was evaporated. To the residue was added a solution of hydroxylamine hydrochloride (58 mg) and sodium bicarbonate (70 mg) in water (0.4 ml) and methanol (0.4 ml) to which had been added normal aqueous potassium hydroxide sufficient to obtain a pH of 9. After 10 minutes ether (20 ml) and 1.0N hydrochloric acid (10 ml) were added. The organic solution was dried and evaporated, and the residue was chromatographed on silica gel, eluting with methylene chloride/methanol/ammonium hydroxide, (40/4/0.3;v/v/v) so as to afford the title compound as a solid, m.p.: 85°-88° C.
EXAMPLE 10
Preparation of Hydroxylamine Derivatives of Various Unsaturated Fatty Acids
Similarly, by using the procedure of Example 9, but substituting heneicosa-5,8,11,14-tetraynoic acid with the following starting materials;
eicosa-5,8,11,14-tetraynoic acid;
nonadeca-5,8,11,14-tetraynoic acid;
docosa-5,8,11,14-tetraynoic acid;
eicosa-6,9,12,15-tetraynoic acid;
docosa-6,9,12,15-tetraynoic acid;
eicosa-4,7,10,13-tetraynoic acid;
docosa-4,7,10,13-tetraynoic acid;
docosa-7,10,13,16-tetraynoic acid;
heneicosa-7,10,13,16-tetraynoic acid;
nonadeca-8,11,14-triynoic acid; and
eicosa-5,8,11-triynoic acid;
there are obtained, respectively:
eicosa-5,8,11,14-tetraynoylhydroxylamine;
nonadeca-5,8,11,14-tetraynoylhydroxylamine;
docosa-5,8,11,14-tetraynoylhydroxylamine;
eicosa-6,9,12,15-tetraynoylhydroxylamine;
docosa-6,9,12,15-tetraynoylhydroxylamine;
eicosa-4,7,10,13-tetraynoylhydroxylamine;
docosa-4,7,10,13-tetraynoylhydroxylamine;
docosa-7,10,13,16-tetraynoylhydroxylamine;
heneicosa-7,10,13,16-tetraynoylhydroxylamine;
nonadeca-8,11,14-triynoylhydroxylamine; and
eicosa-5,8,11-triynoylhydroxylamine.
EXAMPLE 11
Preparation of 1-Hydroxyheneicosa-6(Z),9(Z),12(Z),15(Z)tetraen-2-one
Eicosa-5(Z),8(Z),11(Z),14(Z)-tetraenoic acid (0.5 g) was added to benzene (50 ml) containing thionyl chloride (0.125 ml) and dimethylformamide (0.05 ml). After 16 hours the solution was evaporated to dryness under vacuum, and the residue was dissolved in ether. The solution was cooled to 0° C. and excess ethereal diazomethane was added. After 2 hours the solution was evaporated to dryness under vacuum and the residue was dissolved in tetrahydrofuran (10 ml). To the resulting solution was added a mixture of water (5 ml) and trifluoroacetic acid (1 ml). The reaction was left for 4 hours, and then diluted with water and extracted with hexane. The extract was dried and evaporated, and the residue was chromatographed on silica gel, eluting with hexane/ether (3/1;v/v), to afford the title compound as an oil.
EXAMPLE 12
Preparation of Hydroxymethylketone Derivatives of Various Unsaturated Fatty Acids
Similarly, by using the procedure of Example 11, but substituting eicosa 5(Z),8(Z),11(Z),14(Z)-tetraenoic acid with the following starting materials:
eicosa-5,8,11,14-tetraynoic acid;
nonadeca 5(Z),8(Z),11(Z),14(Z)-tetraenoic acid;
nonadeca 5,8,11,14-tetraynoic acid;
octadeca-5(Z),8(Z),11(Z),14(Z)-tetraenoic acid;
octadeca-4,7,10,13-tetraynoic acid;
heneicosa-4(Z),7(Z),10(Z),13(Z)-tetraenoic acid;
heneicosa-4,7,10,13-tetraynoic acid;
nonadeca-5,8,11,14-tetraynoic acid;
heneicosa-5,8,11,14-tetraynoic acid;
nonadeca-3,6,9,12-tetraynoic acid;
heneicosa-3,6,9,12-tetraynoic acid;
heneicosa-6,9,12,15-tetraynoic acid;
eicosa-7,10,13,16-tetraynoic acid;
nonadeca-4,7,10-triynoic acid; and
octadeca-7,10,13-triynoic acid.
heneicosa-8(Z),14(Z)-diene-5,11-diynoic acid;
heneicosa-8(Z),11(Z),14(Z)-trien-5-ynoic acid; and
heneicosa-5(Z),8(Z),14(Z)-trien-11ynoic acid;
there are obtained, respectively:
1-hydroxyheneicosa-6,9,12,15-tetrayn-2-one;
1-hydroxyeicosa-6(Z),9(Z),12(Z),15(Z)-tetraen-2-one;
1-hydroxyeicosa-6,9,12,15-tetrayn-2-one;
1-hydroxynonadeca-6(Z),9(Z),12(Z),15(Z)-tetraen-2-one;
1-hydroxynonadeca-5,8,11,14-tetrayn-2-one;
1-hydroxydocosa-5(Z),8(Z),11(Z),14(Z)-tetraen-2-one;
1-hydroxydocosa-5,8,11,14-tetrayn-2-one;
1-hydroxyeicosa-6,9,12,15-tetrayn-2-one;
1-hydroxydocosa-6,9,12,15-tetrayn-2-one;
1-hydroxyeicosa-4,7,10,13-tetrayn-2-one;
1-hydroxydocosa-4,7,10,13-tetrayn-2-one;
1-hydroxydocosa-7,10,13,16-tetrayn-2-one;
1-hydroxyheneicosa-8,11,14,17-tetrayn-2-one;
1-hydroxyeicosa-5,8,11-triyne-2-one;
1-hydroxynonadeca-8,11,14-triyne-2-one;
1-hydroxydocosa-9(Z),15(Z)-diene-6,12-diyn-2-one;
1-hydroxydocosa-9,12,15-triene-6-yn-2-one; and
1-hydroxydocosa-6(Z),9(Z),15(Z)-triene-12-yn-2-one.
EXAMPLE 13
Conversion of 5-(Eicosa-4,7,10,13-tetraynyl)-1H-tetrazole into the Sodium Salt
Sodium methoxide (82 mg) is added to a solution of 5-(eicosa-4,7,10,13-tetraynyl)-1-H-tetrazole (500 mg) in methanol (5 ml). The solution is then evaporated to dryness to afford 5-(eicosa-4,7,10,13-tetraynyl)-1-H-tetrazole sodium salt.
In a similar manner, all compounds of formula (1), (2) or (3), wherein X is 1-H-tetrazol-5-yl or C(O)NHOH, in free acid form, may be converted to salts such as potassium, lithium, ammonium, calcium, magnesium, ferrous, zinc, copper, manganous, aluminum, ferric, manganic salts and the like.
EXAMPLE 14
Conversion of 5-(Eicosa-4,7,10,13-tetraynyl) 1-H-tetrazole Sodium Salt into 5-(Eicosa-4,7,10,13-tetraynyl)-1-H-tetrazole
A two-fold stoichiometric excess of N-hydrochloric acid is added to a solution of 5-(eicosa-4,7,10,13-tetraynyl)-1-H-tetrazole in water. The solution is then extracted with ether, and the extract is dried and evaporated to afford 5-(eicosa-4,7,10,13-tetraynyl)-1-H-tetrazole.
In Examples 15 through 22 the active ingredient is heneicosa-5,8,11,14-tetraynoylhydroxylamine. Other compounds of formula (1), (2), or (3) and the pharmaceutically acceptable salts thereof may be substituted therein.
EXAMPLE 15
______________________________________ Quantity perIngredients tablet, mgs.______________________________________Active ingredient 25cornstarch 20lactose, spray-dried 153magnesium stearate 2______________________________________
The above ingredients are thoroughly mixed and pressed into single scored tablets.
EXAMPLE 16
______________________________________ Quantity perIngredients tablet, mgs.______________________________________Active ingredient 100lactose, spray-dried 148magnesium stearate 2______________________________________
The above ingredients are mixed and introduced into a hard-shell gelatin capsule.
EXAMPLE 17
______________________________________ Quantity perIngredients tablet, mgs.______________________________________Active ingredient 200cornstarch 50lactose 145magnesium stearate 5______________________________________
The above ingredients are mixed intimately and pressed into single scored tablets.
EXAMPLE 18
______________________________________ Quantity perIngredients tablet, mgs.______________________________________Active ingredient 108lactose 15cornstarch 25magnesium stearate 2______________________________________
The above ingredients are mixed and introduced into a hard-shell gelatin capsule.
EXAMPLE 19
______________________________________ Quantity perIngredients tablet, mgs.______________________________________Active ingredient 150lactose 92______________________________________
The above ingredients are mixed and introduced into a hard-shell gelatin capsule.
EXAMPLE 20
An injectable preparation buffered to a pH of 7 is prepared having the following composition:
______________________________________Ingredients______________________________________Active ingredient 0.2 gKH.sub.2 PO.sub.4 buffer (0.4 M solution) 2 mlKOH (1 N) q.s. to pH 7water (distilled, sterile) q.s. to 20 ml______________________________________
EXAMPLE 21
An oral suspension is prepared having the following composition:
______________________________________Ingredients______________________________________Active ingredient 0.1 gfumaric acid 0.5 gsodium chloride 2.0 gmethyl paraben 0.1 ggranulated sugar 25.5 gsorbitol (70% solution) 12.85 gVeegum K (Vanderbilt Co.) 1.0 gflavoring 0.035 mlcolorings 0.5 mgdistilled water q.s. to 100 ml______________________________________
EXAMPLE 22
Topical Formulation is prepared having the following composition:
______________________________________Ingredients grams______________________________________Active compound 0.2-2Span 60 2Tween 60 2Mineral oil 5Petrolatum 10Methyl paraben 0.15Propyl paraben 0.05BHA (butylated hydroxy anisole) 0.01Water q.s. 100______________________________________
All of the above ingredients, except water, are combined and heated to 60° C. with stirring. A sufficient quantity of water at 60° C. is then added with vigorous stirring to emulsify the ingredients, and water then added q.s. 100 g. | Novel compounds of this invention are tetrazole, acylhydroxylamine, hydroxymethylketone and amide derivatives of unsaturated fatty acids which are selective inhibitors of the enzymes lipoxygenase and cyclooxygenase involved in the production of pain, inflammation, bronchoconstriction and allergic reactions. These compounds are beneficial in the treatment of a number of inflammatory and/or painful conditions and allergic reactions. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to devices for electromechanical stimulation and testing of hearing.
2. Description of Related Art
Generally, the hearing of an individual is tested such that an acoustic signal and, thus, an acoustic wave are presented via suitable electroacoustic means to the subject monaurally (one ear) or binaurally (two ears) and the subject reacts subjectively to corresponding questions which are matched to the respective purpose of the psychoacoustic examination. These electroacoustic means are collectively called audiometers. In the most frequent applications, the test signal is produced either electronically (analog or digital signal generators) or taken from a suitable audio medium (magnetic tape, compact disk, etc.). These test signals are presented to the subject acoustically usually via loudspeakers under so-called free field conditions or via specially calibrated measurement headphones.
In special cases, these acoustic signals are routed via short acoustic conduction hoses and ear adapters to the external auditory canal, when, for example, a volume which is acoustically tightly closed is required in front of the eardrum for special testing. Moreover, there are objective hearing testing methods (for example: BERA: brainstem evoked response audiometry) in which acoustically evoked neuronal responses are picked up via skin electrodes and analyzed accordingly (Boehme, G., Welzl-Mueller, K.: "Audiometrie: Hoerpruefungen im Erwachsenen-und Kindesalter" Audiometry: Hearing Tests in Adults and Children!. Verlag Hans Huber, Bern, 1988, ISBN: 3-456-81620-0).
In all processes, basically, an acoustic signal is presented which, in a known manner, causes the eardrum to vibrate mechanically, the vibrations are conveyed via the ossicular chain of the middle ear to the inner ear and they are converted there into a neuronal stimulus pattern which leads to a hearing impression.
Especially in objective hearing testing methods (for example, BERA) there are, however, some disadvantages in the type of acoustic excitation, such as for example the magnetic fields generated by the electrodynamic or electromagnetic headphones which are generally used. These magnetic (interference) fields lead to problems in pre-processing and analysis of the evoked potentials which are electrically derived from the skin surface of the head and which can be in the nV range. For acoustic signals monaurally presented supraliminally at medium to high sound levels the problem of "overhearing" of the contralateral ear which is not being tested due to the acoustic sound emission of the headset or by bone conduction continues to occur, which leads to the necessity of acoustic masking of this opposite ear. This effect is undesirable in many psychoacoustic situations, but inevitable.
More recent approaches for partially or fully implantable hearing aids in which (damaged) hearing is no longer acoustically, but mechanically stimulated by direct mechanical coupling of a corresponding transducer to different areas of the middle ear necessitate pre-operative demonstration of the hearing improvement or sound quality to be expected to the subject awaiting implantation. However this is impossible noninvasively with known methods, i.e., without surgery.
SUMMARY OF THE INVENTION
A primary object of the present invention is to circumvent or largely prevent the aforementioned problems by a fundamentally new approach of signal presentation, and to properly enable, in the example of (partially) implantable hearing aids, pre-operative audiological diagnostics.
According to the invention, this object is fundamentally achieved by offering the test or demonstration signals to the hearing, not acoustically, but by direct mechanical stimulation of the ossicular chain of the middle ear, which is accessible from the external auditory canal. For this purpose, a device for electromechanical stimulation and testing of hearing is devised which has an electromechanical transducer for generating mechanical vibrations in the audio range as well as a rigid, mechanical coupling element in order to transmit mechanical vibrations without surgery through the external auditory canal in direct mechanical contact to the center of the eardrum, and thus, to the manubrium of the malleus of the ossicular chain of the middle ear.
In application of the invention, by a suitably trained ENT physician, the vibrating part of the electromechanical transducer is pushed via a suitable coupling element, with optical monitoring and by means of suitable positioning and fixing tools, through the external auditory canal in the central area of the eardrum, the umbo (the site of the eardrum to which the end point of the manubrium is fused), brought mechanically into direct contact with this center, and kept in direct mechanical contact. In this way, the mechanical vibrations of the transducer are coupled directly by mechanical means to the ossicular chain and conveyed to the inner ear, and thus, they lead to an auditory impression.
In particular, to produce audiological test signals, electronic signal generators can be provided with which freely selectable signals can be produced, or signal sources can be used which operate, alternatively or selectively, with audio media, such as magnetic tapes or compact disks. Regardless of the type of signal source, an amplifier with a driving end stage should be provided for supplying the audiologic test signals to the electromechanical transducer.
Insertion of the device according to the invention can be made easier for the examiner, and at the same time for the patient, if the electromechanical transducer is accommodated in a transducer housing which is to be inserted into the entry area of the external auditory canal, with geometrical dimensions which are selected such that the examiner, even when using a microscope, maintains an unobstructed view of the active end of the coupling element which mechanically contacts the center of the eardrum.
Preferably, the coupling element is made as a rod-shaped component which is rigid in the axial direction, with an active end facing away from the transducer which ensures noninjurious mechanical contact to the center of the eardrum. It is especially advantageous if the coupling element is made to be easily manually bent, so that it can be adapted to the individual geometrical shapes of the external auditory canal.
If the coupling element is joined to the transducer, not mechanically fixed, but via a mechanical plug connection, for example, different coupling elements can be implemented which are easily interchangeable for hygienic reasons, and which can be made disposable.
Preferably, the electromechanical transducer, in conjunction with the mechanical coupling element, is made such that the first mechanical resonant frequency is at the top end of the spectral transmission range of≧10 kHz. In this way, short response times can be achieved due to the broad band.
In order to, furthermore, achieve an impression of the deflection of the active end of the coupling element which is independent of the individual fluctuations of the biological load impedance, the electromechanical transducer is preferably made such that its mechanical source impedance is much greater in the entire spectral transmission range than the mechanical load impedance which is formed by the biological system consisting of the eardrum, ossicular chain, and inner ear.
The examination can be made even less onerous for the patient if the electromechanical transducer is acoustically encapsulated by the design of the transducer housing, such that the acoustic signal which is emitted by the vibrating transducer structures is minimized, and so that, at high stimulation levels, acoustic masking of the contralateral ear not being tested can be abandoned.
In another embodiment of the invention, the system composed of a signal source, amplifier and electromechanical transducer with coupling element is made as a pre-operative diagnosis and demonstration device of the transmission quality to be expected in the application of partially and fully implantable hearing aids.
In order to enable simultaneous binaural stimulation and testing of hearing, the device can be made doubled.
These and further objects, features and advantages of the present invention will become apparent from the following description when taken in connection with the accompanying drawings which, for purposes of illustration only, show a single embodiment in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The sole FIGURE of the drawings shows a system according to a preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawing, electrical test signals, for example, pure sinusoidal tones or broadband signals (noise, etc.) are produced by a signal source in the form of a signal generator 10, in which they can be adjusted with respect to functional parameters (frequency, level, time sequences, envelope curves, etc.). These preprocessed signals are amplified with an amplifier 12 which contains a driving end stage which corresponds to the selected transducer principle and they are sent to an electromechanical transducer 14 Alternatively, instead of generating the test signals to be delivered to the amplifier 12 by means of a signal generator 10, the signal source can be signals taken from at least one playback device for producing electrical signals from recorded audio media 16 (e.g., magnetic tapes, compact disks, etc.) as in conventional audiometers.
Transducer 14 can operate according to any known electromechanical conversion principles (dynamic, magnetic, piezoelectric, capacitive/dielectric, magnetostrictive), but, preferably, piezoelectric or capacitive E-field transducer types are selected because of the absence of magnetic interference fields, and transducer 14 is brought near to the inlet of the external auditory canal 18 of the ear being examined using suitable aids. The external dimensions of the transducer 14 are made such that the examiner still has an unobstructed view (broken line of sight 20) through the external auditory canal 18 as far as center 22 (umbo) of eardrum 24. Electromechanical transducer 14 converts the electrical driver signals into mechanical vibrations. These transducer vibrations are transmitted to a coupling element 26 which is mechanically rigid in the direction of its longitudinal axis and which is joined mechanically fixed to the vibrating part of transducer 14 or is connected thereto by means of a plug-in type connection comprising a plug member 38 and a socket member 40. Coupling element 26, which is shown in the drawing as a rod-shaped component, after its end 28 facing away from the transducer 14 having been inserted by the examiner, mechanically contacts the center 22 (umbo) of the eardrum 24 with slight pressure. Thus, the mechanical transducer vibrations are transmitted via the ossicular chain, consisting of the malleus 30, incus 32, and stapes 34, to the inner ear or the cochlea 36 in order to lead to an auditory impression. The end 28 of the rod-shaped coupling element 26 is designed and surface treated, such that, on the one hand, after positioning and insertion, slipping off from umbo 22 is prevented, and on the other hand, the danger of injury to this eardrum area can be excluded.
Since the geometrical dimensions of the external auditory canal 18 are subject to anatomically individual fluctuations and auditory canal 18 runs at a slight angle, rod-shaped coupling element 26 preferably is made such that, on the one hand, it has as high a stiffness as possible in the axial direction to prevent mechanical resonances in the audio range, and on the other hand, it can be easily manually deformed (bent) by the examiner in order to adapt to the slight individual curvature of the auditory canal 18, and thus, to avoid contact of the vibrating coupling element with areas of the external auditory canal. As mentioned above, it is also advantageous if the coupling element 26 is not fixed to transducer 14, but, for example, is connected thereto via plug device 38, 40. In this way, coupling elements of different length can be made for individually different lengths of the external auditory canal 18, and these different coupling elements can be produced inexpensively so as to, thus, be manufactured as disposable articles for hygienic reasons in mass examinations.
More advantageously, the overall electromechanical system formed of the transducer 14 and coupling element 26, with regard to its dynamic parameters mass and stiffness which determine its operating behavior, is dimensioned such that, on the one hand, there is a system set to above resonance, i.e., the first mechanical resonant frequency is at the upper end of the desired transmission frequency range (≧10 kHz). In time behavior, a short transient recovery time of the system is achieved by this broad band; this leads to good pulse transmission behavior of the system. On the other hand, the mechanical source impedance of this system should be clearly above the biological load impedance which is formed by the system eardrum, ossicular chain and coupled hydromechanical inner ear in order to achieve a frequency-independent impression of the deflection of the transducer and thus of the coupling element. In this way, it is possible to compare interindividual audiometry results since the stimulus level is then independent of the unknown, individual variation of the mechanical (biological) load impedances.
The mechanical deflection of coupling element 26 which can be achieved with the overall system consisting of the end stage which drives transducer 14, and transducer 14 itself, for audiologic subjective and objective hearing tests, should achieve values which correspond to an equivalent sound level which is at the upper end of the audiologic dynamic range, therefore, roughly 120 to 130 dB SPL. At low and medium frequencies, this corresponds to roughly 1-2 kHz deflection amplitudes of roughly 1-5 microns.
If the electromechanical transducer is acoustically enclosed within a suitably designed transducer housing 42, the inevitable acoustic sound emission of the vibrating transducer parts at high stimulation levels can be minimized, such that additional acoustic excitation of the tested ear or overhearing by the contralateral ear is eliminated, whereby the necessity of acoustic masking of the contralateral ear is prevented.
If in the case of application of a partially or fully implantable hearing aid, the electromechanical transducer of this implant system is used as the transducer 14, and the signal pre-processing module of this implant system is used as the amplifier 12, the device according to the invention can be used for pre-operative assessment of the transmission quality and suitability of the stipulated implant system for the pertinent proband.
Furthermore, the device according to the invention, in a doubled version, can be used for both ears in a proband for purposes of simultaneous binaural audiometry.
While a single embodiment in accordance with the present invention has been shown and described, it is understood that the invention is not limited thereto, and is susceptible to numerous changes and modifications as known to those skilled in the art. Therefore, this invention is not limited to the details shown and described herein, and includes all such changes and modifications as are encompassed by the scope of the appended claims. | A device for electromechanical stimulation and testing of hearing in which an electromechanical transducer transmits audiologic signals as mechanical deflections via a coupling element from the outside, noninvasively through the external auditory canal, by direct mechanical coupling with the manubrium of the malleus to the ossicular chain. In preferred embodiments, by suitable selection of the transducer principle disruptive magnetic stray fields and acoustic stimulation by sound transmission to the contralateral ear, which is not being examined, are prevented. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is concerned with the use of nonlinear devices for the conversion of infrared frequencies to higher or lower values. Such devices include but are not limited to second harmonic generators and parametric amplifiers. The invention lies in the discovery that the ternary ferroelectric fluorides, represented by the formula BaXF 4 where X is a divalent transition metal ion, will frequency double 1.06 microns at room temperature and under noncritically phase-matched conditions. The preferred noncritically phase-matched condition is relatively insenitive to normally encountered ambient temperature variations. Consequently these materials can be noncritically phase matched at 1.06 microns without the support of sophisticated thermal equipment.
2. Description of the Prior Art
The initial application of optical, infrared and ultraviolet lasers to both research and applied projects was severely limited by the relatively limited number of frequencies at which these devices operated. The first major advance in enlarging this scope of operation involved the use of nonlinear devices. Such devices are able to convert a given frequency to one of higher value, or two frequencies to their sum or difference value. While significantly broadening the scope of laser operation, even this extension left the vast majority of the optical spectrum neglected, from the point of view of available laser operation. The next major advance, the development of the dye laser, essentially filled this void. The entire visible region of the spectrum, and large portions of the infrared and ultraviolet regions are now accessible through the use of dye lasers. However, despite the dye laser, the tenure of the nonlinear devices has not been eclipsed. A number of unique attributes account for their longevity. Firstly, the nonlinear devices are, operationally, simpler than dye lasers and hence more able to withstand the rigors of applied technology. Secondly, in many regions of the spectrum they are more efficient than the dye systems. Thirdly, and of greatest interest in lght of the invention described below, certain near infrared lasers can be miniaturized ans still emit at relatively high power levels. Under these circumstances they are more desirable than the larger and more power-limited dye lasers. The utility of such lasers would, of course, be increased if second harmonic generation would be available to transform this light into the visible.
Among the most readily avialable infrared lasers there are a significant number that emit at 1.06 microns, and hence considerable interest has centered around second harmonic generators which operate at this wavelength. While a number of materials have been discovered which can perform this function, they must be operated at elevated temperature and under strict temperature control in order to realize the full potential available only with noncritical phase-matched conditions. In addition, the susceptibility of some of these materials to radiation damage severely limits their useful power range. The materials described in this specification are the first which are capable of doubling 1.06 microns under the preferred noncritical phase-matched conditions at room temperature and without significant temperature control. In addition, this material can tolerate higher power levels than presently available frequency doublers which operate at 1.06 microns. The discovery of these characteristics enhances the value of available miniature light sources which emit 1.06 microns by enabling the transformation of their output to 0.53 micron yielding a minature light source in the visible.
The description of nonlinear processes may be considerably simplified by using second harmonic generation, perhaps the most elementary of nonlinear phenomena, as a primary example, and as a vehicle to discuss the prior art. The discovery, and first demonstration of second harmonic generation, was made in 1961 by Franken et al. and is described in Volume 7 of the Physical Review Letters at page 118. Franken focused the 6943 Angstrom light beam of a ruby laser onto a quartz crystal and found that one part in 10 8 of this light was converted to second harmonic light with a wavelength of 3471.5 Angstroms. This is exactly half the wavelength and hence twice the energy of the incident light. The basis for this phenomenon can be most readily understood by considering the response properties of a nonlinear material such as quartz. The response of the electrons in such a material to the incident light depends upon the direction of the electromagnetic field associated with this light. The electrons in a nonlinear material are more amenable to motion in one direction than in an other. Thus the electrons move asymmetrically in response to the highly intense incident light and their motion may be represented by a harmonic wave asymmetric about the zero level. Such a dynamic response may be effectively shown to be equivalent to the sum of two simple harmonic motions, one at the incident frequency and one at twice the incident frequency, and a constant nonzero bias value. Second harmonic generation originates with the generation of light associated with the motion which is at twice the frequency of the incident light.
The production efficiency of the frequency-doubled light is severely limited, however, because of the natural dispersion of the nonlinear material. As in all materials, the velocity of light in the medium depends on the frequency of the light and varies inversely with it. As a result of this dispersion, the frequency-doubled light travels more slowly in the medium than the incident light. The incident light travels through the medium at its more rapid speed causing the generation of additional frequency-doubled light as it goes. The previously produced frequency-doubled light may find that by the time it reaches the site of newly generated light it is out of phase with it. The two waves, when they are thusly out of step, are said to be mismatched with respect to phase and desstructively interfere with each other. The amount of frequency-doubled light emitted by the crystal is then significantlly diminished.
As a result of the phase mismatch problem, the application of nonlinear phenomena to practical devices was impeded until a critical discovery by Giordmaine and Kleinman (U.S. Pat. No. 3,234,475). They realized that the birefringent properties of certain nonlinear materials might be used to compensate for the dispersive effect and thereby alleviate the phase mismatch. In a birefringent material, light of a given frequency and vector wave number will travel in two different modes. The polarization of these two modes will be orthogonal to each other and their velocities will be different. In a negative uniaxial crystal, the velocity of one of these modes, the extraordinary ray, will be greater than that of the other mode, the ordinary ray. If the incident light is in the ordinary ray mode and the frequency-doubled light is in the extraordinary mode, then the two velocity affecting phenomena come into play. Dispersion tends to lower the velocity of the frequency-doubled light relative to the incident light while birefringence tends to have the opposite effect. Since the magnitude of the birefringence depends on the angle of incidence between the incident light and the optic axis of the crystal, it is conceivable that an angle can be chosen for which the birefringence is of exactly the right magnitude to cancel the effect of dispersion. Under such conditions phase matching is said to exist and the production efficiency of frequency-doubled light rises by orders of magnitude. Angle tuning the birefringence, as just described, has one severe drawback. Unless the angle of incidence is 90°, that for which maximum birefringence occurs, a refractive phenomenon known as walkoff occurs with a resultant loss of efficiency. It is clear then that noncritical phase matching, which describes a phase-matched condition with incident angle of 90°, is most desirable. However, it is also clear that the phase-matching condition will not necessarily be met at a 90° angle of incidence.
In a patent issued in 1966 to Ballman, Boyd, and Miller (U.S. Pat. No. 3,262,658) another technique for controlling the birefringence was disclosed, thereby allowing a preset 90° angle of incidence. These inventors disclosed that the birefringence-dispersion relationship can be controlled by temperature variation. Noncritical phase-matched conditions could then be attained by operating at the proper temperature. Such a material can be operated under noncritically phase-matched conditions at any given frequency over a wide region of the spectrum by merely setting the temperature accordingly. However, the very attribute that allows for temperature tuning dictates careful temperature control. Small temperature variations will detune the crystal from the desired operating conditions. When a given frequency is to be used extensively, the most desirable material would be one that, in addition to being noncritically phase matched at room temperature for the desired frequency, is insensitive to temperature variation. The ternary ferroelectric fluorides described in this specification have these qualities when operated at 1.06 microns.
Despite the fact that 15 years have elapsed since the first demonstration of second harmonic generation, the number of effective and efficient nonlinear materials remains relatively limited. The most widely used of these materials take advantage of the temperature tuning technique. So, for example, the 1.06 micron line of the common glass lasers can be frequency doubled to 0.53 micron using LiNbO 3 , BA 2 Na(NbO 3 ) 5 , ADP or KDP. However all of these materials require elevated temperatures to operate under the more efficient noncritical phase-matched condition at this wavelength. In addition, in these materials the noncritically phase-matched condition is extremely sensitive to variations in the applied temperature. Elaborate temperature equipment is then necessary to both elevate the material to the proper temperature and to maintain it at this temperature without even small temperature variations. Unlike these materials, the materials disclosed in this application have been found to be noncritical phase matchable at 1.06 microns under room temperature conditions. In addition it has been found that this noncritical phase matching at room temperature is essentially insensitive to temperature variations normally encountered in ambient environments. The ternary ferroelectric fluorides described in this application are the first materials that have been found to display these characteristics. Because of the proliferation of small solid-state lasers which emit at 1.06 microns a material with these characteristics has been long sought. Its discovery enhances the value of all such infrared lasers.
Other considerations in evaluating a material for use in a nonlinear device, which are not central but nonetheless important, include (a) maximum allowable power levels of the incident radiation, (b) degree of nonlinearity, and (c) material stability under conditions of use.
While the above discussion has been in terms of second harmonic generation, it is clear that there are a host of other nonlinear phenomena to which a viable material might be applied. Such other devices, which might be utilized through the practice of the present invention, include parametric amplification, oscillation, mixing, etc. The operation of such devices is thoroughly understood to those skilled in the art.
SUMMARY OF THE INVENTION
Applicants have discovered that ternary ferroelectric fluorides BaXF 4 , where X is a divalent transition metal ion, are possessed of characteristics that make them highly useful in nonlinear devices. At the present they are the only materials that are known to be noncritically phase matchable at 1.06 microns under room temperature conditions. In addition they are relatively insensitive to normal temperature variations encountered in ambient environments. In experiments on radiation damage it was found that these materials can withstand power levels of 10 9 watts/cm 2 when presented in the form of 100 nsec. pulses at the rate of 100 pulses/sec. The crystals are of the space group Cmc2 1 and may be grown by the Bridgeman technique under conditions well known to those skilled in the crystal growing art.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic plot of the observed index of refraction for the ternary ferroelectric fluorides described in this application. The index of refraction is plotted on the ordinate and the wavelength in microns on the abscissa; and
FIG. 2 is a schematic representation of a nonlinear device using a ternary ferroelectric fluoride as the active element.
DETAILED DESCRIPTION
In the course of a search for new nonlinear materials, applicants performed an extensive study of the linear and nonlinear properties of BaMgF 4 and BaZnF 4 . Three quantities must be measured to evaluate the applicability of such materials in nonlinear devices. The first is the index of refraction of both the ordinary and extraordinary waves. If the birefringence is to be effective in eliminating the destructive interference of the induced wave within the crystal, then it must be sufficiently large so as to compensate for the dispersion difference between the original and induced frequencies. This requirement may be expressed by the formula:
n.sub.ω.sup.o ≧ n.sub.2.sub.ω.sup.e (1)
Here n is the index of refraction, o and e refer to the ordinary and extraordinary rays, respectively, and ω and 2ω are any given frequency and its harmonic. The indices of refraction for BaMgF 4 and BaZnF 4 were measured by cutting the crystal into thin wedges with wedge angle less than 5° and utilizing the well-known minimum deviation technique. FIG. 1 is a schematic representation of the results of these measurements, made throughout the visible and infrared for both the ordinary and extraordinary rays. It is clear that the phase-matching condition as expressed in Equation (1) may be obtained for incident radiation of wavelength greater than or equal to approximately 1.06 microns.
The other quantities of interest in nonlinear materials are the coherence length and the relevant nonlinear coefficients. The coherence length is that length through the crystal whose traversal will cause a transmitted wave to be 180° out of phase with a newly generated wave. The nonlinear coefficients are related to the efficiency of second harmonic light production within the crystal. The coherence lengths and the nonlinear coefficients were measured using the same 5° wedges mentioned above. A Q-switched Nd-doped YAG laser emitting at 1.06 microns was used to irradiate the wedge and the second harmonic signal was observed. Translation along the wedge direction gives alternating maxima and minima. The length between maxima is a measure of the coherence length.
Adjusting the wedge for emission of the second harmonic peak allows for the measurement of the nonlinear coefficient. The components of the vector nonlinear polarization P at the second harmonic frequency may be given in terms of E, the electric field associated with the impinging light and the tensor of nonlinear coefficients d, i.e.,
P = d E.sup.2 (2)
various symmetry arguments may be used to simplify this expression, and for the case of a crystal of Cmc2 symmetry, such as BaMgF 4 and BaZnF 4 ,
p x = d 15 E x E z , (3a)
P y = d 24 E y E z , (3b)
P z = d 31 E.sub. x 2 + d 32 E.sub. y 2 + d 33 E z .sup. 2. (3c)
A further relation among the coefficients, according to the Kleinman symmetry condition, is
d.sub.15 = d.sub.31, d.sub.32 = d.sub.24 (4)
According to Equation (3c) polarizing the impinging light along the x, y and then the z directions gives d 31 , d 32 and d 33 , respectively. According to Equation (3a) polarizing the impinging light in the x-z plane but intermediate between the x and z direction permits the measurement of d 15 . In addition to these measurements, it was determined that the birefringence properties of BaMgF 4 and BaZnF 4 are essentially insensitive to normal temperature variations encountered in an optics laboratory. No optical damage was observed when a focused 1.06 micron fundamental of intensity of approximately 10 9 watts/cm 2 was incident on the crystal, in the form of 100 nsec. pulses at the rate of 100 pulses/sec. This may be compared, for example, with LiNbO 3 which displays significant radiation damage when exposed to power levels of 10 6 watts/cm 2 , under similar irradiation.
Table I is a tabulation of the observed coherence lengths and nonlinear coefficients BaMgF 4 and BaZnF 4 .
TABLE I______________________________________Observed Nonlinear Coefficients (d's) andCoherence Lengths (l's) forBaMgF.sub.4 and BaZnF.sub.4 *______________________________________ BaMgF.sub.4 BaZnF.sub.4______________________________________d.sub.33 0.05 0.11d.sub.31 0.07 0.025d.sub.15 0.07 0.033d.sub.32 0.13 0.25d.sub.24 0.07 --l.sub.33 29.3 28.0l.sub.31 -- 112l.sub.15 23.3 20.2l.sub.32 9.6 9.82l.sub.24 170.0 --______________________________________ *Nonlinear coefficients (d's) are given relative to d.sub.11 (SiO.sub.2) ±20%; coherence lengths (l's) are given in microns for ω = 1.06μ, 2ω = 0.53μ; the relative signs (BaZnF.sub.4 :d.sub.33 d.sub.31 < 0, d.sub.33 d.sub.32 > 0; and BaMgF.sub. 4 :d.sub.33 d.sub.32 0) were determined by interference techniques.
In evaluating the constants displayed in Table I it is important to bear in mind that the resistance of the ternary barium fluorides to radiation damage plays an important role in enhancing their utility. Because these materials are ionic in nature, they can withstand power levels which in other materials would result in significant radiation damage. As a result, the relatively small nonlinear coefficients associated with the ternary ferroelectric fluorides can be more than compensated by greater input powers. The result of this coupling of larger input powers with an admittedly small nonlinear coefficient is a net gain in realizable ouput power. The input powers necessary to realize this gain are readily available from present day glass lasers.
FIG. 2 is a schematic of the nonlinear device using BaMgF 4 or BaZnF 4 as the active element. In this Figure, 11 is a source of coherent radiation, 12, and will be a laser in most cases. The light generated by the nonlinear device, 14, is detected at 15. This impinging beam is shown entering the crystal, 13, at an angle Φ relative to 16, the optic axis of the crystal. Any optics necessary to properly focus the light on 13 is included in 11. Likewise, 15 may include any optics necessary to efficiently collect the emitted light 14, and may include a narrow band filter. In certain applications, the device may be operated with a resonant means in order to support a standing wave of one of the frequencies in the crystalline body. In such an event, 17 and 18, shown in the FIG. 2, would represent an appropriate resonant means, such as partially reflecting mirrors, necessary to support the standing wavelength.
In the preferred embodiment, the emitted light 14 is the second harmonic of the impinging light 12. Under these circumstances, 12 may be any wavelength greater than or equal to approximately 1.06 microns although the fullest advantage is derived from this invention when 12 is about 1.06 ± 0.1 microns.
The device of FIG. 2 might also be used as a mixer or a parametric oscillator. In such a case, 12 would be the two input frequencies and 14 would be the output beam.
While the experimental work has involved only BaMgF 4 and BaZnF 4 , similar results should appear with other ternary ferroelectric fluorides. Specifically, the compound BaXF 4 , where X is a divalent transition metal ion and the resultant crystal is isomorphous with BaMg 4 and BaZnF 4 , should exhibit nonlinear properties similar to those reported here. This similarity is expected since the electronic structure of the crystal, which yields the nonlinear properties, is comparable in all of the compounds. Although the size of the transition metal ion class varies, depending on the specific notation being followed, those elements suitable for substitution in the above compound include Zn, Ni, Co, Fe, Mn, and Mg. Slight variations in the electrical substructure of these elements may have some small effect on the nonlinear properties of the BaXf 4 crystal, but not large enough to substantially change from the overall properties observed. Likewise, the element X may include mixtures of the above elements with little substantial change in the nonlinear properties.
The invention then comprises a nonlinear device with a ternary ferroelectric barium fluoride as the active element. The preferred embodiment involves second harmonic generation, i.e., 0.53 micron from a 1.06 micron fundamental. Alternatively, the device may be used to frequency double any wavelength above 1.06 microns under critically phase-matched conditions, though the useful upper limit is about 8 microns where absorption occurs. | The nonlinear properties of the ternary ferroelectric barium fluorides permit noncritical phase matching in the vicinity of 1.06 microns at room temperature. The crystals can tolerate powers of up to approximatey 10 9 watts/cm 2 and may be used as the essential element in second harmonic generators. These devices operate at room temperature without any need for sophisticated temperature control. | 6 |
FIELD OF THE INVENTION
The present invention relates to a device for removing finished cigarette packages from the output conveyor of an intermittent motion production machine for the purpose of performing additional processes of inspection by a Machine Vision System. If the cigarette packages satisfy the quality checks performed by the Vision System they are returned to the production machine output conveyor from whence they came with the same orientation and sequence. If any cigarette packages fail the quality checks they are automatically ejected from the device and thus prevented from returning to the good product flow.
BACKGROUND OF THE INVENTION
It is well known that modern industry is placing greater emphasis on Quality Control than ever before. In an effort to enhance the on-line quality control capabilities of their production machines, manufacturers are turning more and more to Machine Vision. Unfortunately most established production machines were not designed with Machine Vision in mind, therefore it is not always possible for a video camera to obtain a clear unobstructed view of the product due to mechanical restrictions. Mechanical re-design of the machine would be intricate, costly and not entirely effective.
In a cigarette packaging machine a bundle of twenty cigarettes are first wrapped in a paper jacket, then proceed to an overwrap station where the packages receive an outer jacket of Cellophane which is folded and heat sealed on three sides; the packages then travel only a short distance before they are inserted into cartons.
It is necessary for a Machine Vision System to perform final quality checks on the cigarette packages after they emerge from the heat sealers and before they are inserted into cartons; the following list summarizes the type of defects which are looked for in this area:
Crumpled packages
Missing Cellophane
Imperfect side seals
Open Cellophane end flaps
Wrinkled Cellophane
Missing or misplaced tear tape
In prior machines some of the package surfaces which must be viewed by the video cameras in order to detect the above mentioned defects are not clearly visible due to the mechanical obstructions in the packaging machine conveyor path.
FIG. 1 illustrates the output area of a conventional cigarette packaging machine where pairs of cigarette packages 10 having been wrapped in cellophane, emerge from a heat-sealer 12 and move along a first predetermined path 14 into one of eight receptacles 16 in a rotatable turret 18 which is rotated in intermittent increments of 45° by a mechanical indexing mechanism 22, thus sliding the packages over the fixed baseplate 20 and along a second path to a transfer position 28 where they are transferred by a mechanical pusher 30 to a third predetermined path 14a from where they are inserted into cartons. Any packages which have been found to be defective by certain up-stream sensors (not shown) will be rejected from the turret at the reject station 24. At this station the fixed base plate 20 has a cut-out which is larger than the packages; this gap is normally bridged by a movable plate 26 which is automatically moved aside when a known defective package is indexed into the reject station 24 allowing the defective package to drop into a defective product container 32.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a device for removing cigarette packages from the output conveyor of an intermittent motion production machine in order that the video cameras of a Machine Vision System may obtain clear unobstructed images of the areas of interest in a quality control inspection application.
This object is achieved in a cigarette packaging machine wherein finished cigarette packages are advanced along a first predetermined path, inserted into one of many receptacles in a rotatable turret where they are moved along a second path to a transfer position where they are pushed from the turret to a third predetermined path, the improvement comprising:
(a) a rotatable indexing wheel having spaced cigarette package receiving pockets, the pockets being moved into alignment with a given position of the second path between the receiving and the transfer positions;
(b) means for guiding cigarette packages into a predetermined pocket;
(c) means for rotating the indexing wheel so that the packages in the pockets are advanced sequentially to each of two vision inspection stations;
(d) means for restraining the cigarette packages against the effects of centrifugal force while they are being indexed by the wheel;
(e) means for inspecting the cigarette packages at the two vision stations, on at least three package surfaces of each cigarette package, to determine those packages which are defective;
(f) means for removing defective packages from the indexing wheel, to prevent them from re-entering the finished product flow; and
(g) means for returning those cigarette packages which have successfully passed inspection, to a turret receptacle at the given position of the second path so that the cigarette packages are in the same orientation and sequence as they were removed from the turret.
The present invention offers the following advantages over the prior art. It enables a Machine Vision System to inspect cigarette packages with a clear unobstructed view of the areas of interest. It is an add-on device which can be implemented with a minimum amount of modification to existing production machines.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sketch of the output area of a prior art cigarette packaging machine before the inspection indexing wheel is added;
FIGS. 2 and 2A are views of an inspection indexing wheel in accordance with the invention;
FIG. 3 is a cigarette packaging machine which is a combination of FIG. 1 and FIG. 2 showing the indexing wheel blended into the rotatable turret of the cigarette packaging machine;
FIG. 3a is a view as seen by one of the video cameras; and
FIG. 4 is a block diagram of the electrical control circuit for controlling the FIG. 3 machine.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Where parts correspond to those in FIG. 1, the same reference numerals will be used.
FIG. 2 is a pictorial of an indexing wheel 34 which consists of two identical side plates 36 each having four pairs of fingers 38; the side plates 36 being spaced apart and locked into registration with each other by four guide plates 40 This wheel rotates on ball bearings about a fixed shaft 42. A guide block 40a is mounted to the fixed shaft 42 between the side plates 36; this guide block 40a has a concave radius which provides a peripheral guide for the cigarette packs 10 (see FIGS. 1 and 3) as they are indexed into the indexing wheel 34 by the rotatable turret 18 (FIG. 1). A pulley 44 mounted on one of the side plates 36 is driven through a timing belt 46 by a stepper motor 48 connected to a programmable stepper motor controller 50. A slotted cylinder 70 is fixed to the pulley 44 and rotates within the slot of a photo-electric sensor 72. The slotted cylinder 70 has four slots spaced at 90° intervals around its circumference.
A wire 56 around the perimeter of the indexing wheel 34 provides a restraint against the effect of centrifugal force on the cigarette packages while they are in motion. Other types of restraining means can be used as will suggest themselves to those skilled in the art. A pivoted reject door 52 operated by a pneumatic cylinder 54 provides a means for removing defective packages from the indexing wheel. Other types of rejecting means can also be used.
Turning back to FIG. 1, the movable plate 26 is removed from the reject station 24 to provide an open area in which the indexing wheel 34 may rotate. The fixed base plate 20 is replaced with one having extended outrigger plates 20a (FIG. 3) on which the fixed shaft 42 (FIG. 2) is mounted. The indexing wheel 34 is installed so that the upper surface of each guide plate 40 (FIG. 2) lines up perfectly with the upper surface of the new base plate 20. With the indexing wheel in this position the slotted cylinder 70 is adjusted so that the photoelectric sensor 72 is seeing light through one of the slots.
Turning now to FIG. 3, two electrical signals must be provided by the packaging machine control system 64 to the programmable stepper motor controller 48, these are:
(a) A machine control system 64 produces a synchronization signal over lead 66, which occurs at the precise time that the rotatable turret 18 has completed its index. This signal is derived from a cam operated switch (not shown) on the mechanical indexing mechanism 22.
(b) The machine control system 64 also produces a defective package signal over lead 68; this is the signal which would have initiated the operation of the movable plate 26 at the reject station 24 (FIG. 1) which has now been removed.
The description which follows will refer to Station #1 thru #4; these stations are locations or positions at which each cigarette package receiving pocket will momentarily stop after an index of the indexing wheel 34.
Turning again to FIG. 3 it will be seen that after a pair of cigarette packages 10 are transferred from the second path into the indexing wheel 34 at Station #1, they will sequentially arrive at Stations #2 thru #4. The function of these Stations is as follows:
Station #1. This is the transfer station where all packages 10 enter the indexing wheel 34 and where all those packages 10 which have been judged as "good product" will exit the indexing wheel.
Station #2. This is the first Vision Inspection Station. Here the packages 10 are indexed into an array of three mirrors 58. These mirrors are angled so that the video camera 60 can obtain an image of three sides of the two cigarette packages in addition to the front surface of the front pack as depicted in FIG. 3a. The camera view is illuminated by a xenon strobe light (not shown) transmitting through several fiber optic cables (not shown).
Station #3. This is the second Vision Inspection Station where the video camera 62 is checking primarily for the presence and correctness of the "tear tape" which is embedded in the Cellophane wrapper. This "tear tape" can be difficult to discern under normal lighting but will "fluoresce" under ultra-violet light; this is why this second Vision Inspection Station is necessary and an ultra-violet light source (not shown) is provided.
Station #4. this is the Reject Station where all defective packages will be removed from the indexing wheel 34. The judgement that a package is defective will come from one or more of three sources:
1. The Packaging Machine reject shift register which remembers that a particular package failed a check imposed by one of its sensors.
2. The vision inspection performed at Station #2 of the indexing wheel 34.
3. The vision inspection performed at Station #3 of the indexing wheel 34.
Information from the above three sources is inserted into the appropriate cell in a shift register (now shown) which is programmed within the stepper motor controller 48 and the defective packages are tracked as they are indexed around the indexing wheel 34. During the index motion of defective packages between Station #3 and Station #4 the stepper motor controller 50 issues an electrical signal to an air solenoid valve (not shown) which permits compressed air to retract the piston of air cylinder 54 causing the reject door 54 to hinge open. In order to assist ejection at the same time another air solenoid valve (now shown) can be energized and compressed air is directed through the center of the fixed shaft 42 and thus through air jets (now shown) directed at the packages at Station #4.
Let us now pick a point in time coinciding with the completion of the index of the rotatable turret 18. At this point in time the status of the packages at the four stations of the inspection indexing wheel are as follows:
Station #1. This pair of packages have just been loaded into the indexing wheel and have as yet received no Vision inspection process.
Station #2. This pair of packages have received the Vision inspection process associated with Station #2.
Station #3. This pair of packages have received the Vision inspection processes associated with both Station #2 and Station #3.
Station #4. A pair of packages present at this station at this point in time must have satisfied the Vision inspection criteria associated with both Station #2 and Station #3 and had not been previously tagged as defective product when it entered the indexing wheel; this pair of packages will be returned to the rotatable turret 16 from whence it came.
At the instant the index of the rotatable turret 18 is completed the cigarette packaging machine control system 64 sends a synchronization signal 66 to the stepper motor controller 50 which issues a sufficient number of electrical impulses to the stepper motor 48 to drive the indexing wheel through an angle of 90° thus advancing each pair of packages to the next station. At the completion of this 90° index the stepper motor controller 50 issues an electrical signal to the Machine Vision System to initiate the Vision inspection processes at Stations #2 and #3.
The "good" pair of packages which were previously at Station #4 are now back at Station #1 in a turret receptacle 16 (FIG. 1) in the same sequence and orientation as before and waiting for the next index of the rotatable turret 18 at which time they will be moved out and replaced by another pair of cigarette packages 10.
In FIG. 4 the electrical control circuit is shown in detail. The synchronization signal over 66 (FIG. 3) issued by the machine control system 64 causes the stepper motor controller 50 to transmit a fixed number of electrical pulses to the stepper motor 48 which will rotate the indexing wheel 34 (FIG. 3) through an angle of exactly 90°. As the last electrical pulse is sent to the stepper motor 48 the stepper motor controller 50 expects to receive a signal from the indexing wheel position sensor 72 confirming that the indexing wheel 34 (FIG. 3) completed the 90° index, if this signal is absent a jam has occurred and the indexing wheel 34 (FIG. 3) has failed to follow the stepper motor 48 through a full 90° index When a jam is detected the stepper motor controller 50 shuts off the holding current to the stepper motor 48 and energizes an indicator light at the operator control station 78; the indexing wheel 34 (FIG. 3) is now free to be turned manually by the operator in order to clear out the jam. When the jam is cleared the operator presses a push-button switch at the operator control station 78 at which time the stepper motor controller 50 sends electrical pulses to the stepper motor 48 causing the indexing wheel 34 (FIG. 3) to rotate slowly until a signal is received from the indexing wheel position sensor 72 indicating that the indexing wheel 34 has reached its home position at which time the stepper motor 48 will be stopped instantly.
When the indexing wheel 34 stops at the completion of a normal 90° index the stepper motor controller 50 issues a command to the vision system 76 which then captures images from both video cameras 60 and 62. If a defect is found in either of these two images the vision system 76 sends a signal to the appropriate cell of a shift register programmed within the stepper motor controller 50 which will activate the reject mechanism 54 when the known defective package indexes into Station #4 (FIG. 3). If a package has been previously found defection by the prior art machine, the machine control system 64 sends a signal 68 to the stepper motor controller 50 at the time that the defective package enters the indexing wheel 34. This signal 68 is inserted into the shift register programmed within the stepper motor controller 50 and the defective package is rejected at Station #4 regardless of the results of the visual inspection. The machine vision system with cameras 60 and 62 has been briefly described since such systems are commercially available and their operation is well known to those skilled in the art.
The invention has been described in detail with particular reference to a preferred embodiment thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. | Apparatus for removing cigarette packages from a packaging machine for the purpose of inspection by a Machine Vision System includes an index wheel and machine vision machine for detecting defective packages and returns only good packages to the machine output flow. | 1 |
TECHNICAL FIELD
[0001] The present inventions relate to improvements in methods and apparatus used to install tubing in a wellbore. More particularly the present inventions relate to methods and apparatus for using and installing radially expandable tubular members including production liners and screens in subterranean well locations.
BACKGROUND OF THE INVENTIONS
[0002] Radially expandable tubular members are typically moved into the well through the existing well tubing and then expanded radially to a larger diameter. Radial enlargement is accomplished by forcing an expanding die axially through the length of tubing. An example of this prior art procedure is described in the United States Patent to Lohbeck U.S. Pat. No. 5,366,012 issued Nov. 22, 1994 entitled Method of Completing an Uncased Section of a Borehole. According to the Lohbeck patent, a tapered expansion mandrel 15 connected to drill string 16 is forced through the tubular member to deform it into larger diameter. The mandrel had a largest diameter greater than the internal diameter of the tubular member. In the United States Patent to Kinley U.S. Pat. No. 3,191,677 entitled Method and Apparatus For Setting Liners in Tubing a pall shaped expander is used. In the United States Patent to Kinlay et al. U.S. Pat. No. 3,785,193 issued Jan. 15, 1974 entitled Liner Expanding Apparatus, a tubing expander device is disclosed which is positioned in the well in a retracted condition and once in position is expanded to engage the tubing. Using expansion mandrels and dies requires large axial forces and creates large friction forces, which can cause damage to the tubular member. Rotating mandrels with off set rollers thereon have been attempted but require rotational power sources.
SUMMARY OF THE INVENTIONS
[0003] The present inventions contemplate an improved apparatus and methods of expanding tubular members in wellbores that overcome the problems associated with forcing expanding dies through lengths of tubing and failures caused by the large frictional forces encountered during expansion.
[0004] According to the present invention a plurality of sets of rollers carried on a tool body are moved axially through the tubular member. The roller sets define an effective cross section that is larger than the cross section of the internal diameter of the tubular member. The rollers rotate during the expansion process by engaging and rolling along the interior wall of the tubular member. The rolling action reduces friction and damage to the tubular member caused thereby.
[0005] In one embodiment, the roller sets are arranged with increasingly larger effective cross sections to progressively expand the tubular member. In one embodiment the rollers are retracted when the tool is moved into the well and extended to engage and expand the tubular member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The accompanying drawings are incorporated into and form a part of the specification to illustrate several examples of the present inventions. These drawings together with the description serve to explain the principals of the inventions. The drawings are only for the purpose of illustrating preferred and alternative examples of how the inventions can be made and used and are not to be construed as limiting the inventions to only the illustrated and described examples. The various advantages and features of the present inventions will be apparent from a consideration of the drawings in which:
[0007] [0007]FIG. 1 is a horizontal sectional view illustrating a subterranean location in a wellbore, illustrating an expandable tubular member being lowered into position;
[0008] [0008]FIG. 2 is a horizontal sectional view similar to FIG. 1 illustrating the tubing installed and after it is expanded in the wellbore using the apparatus and methods of the present inventions;
[0009] [0009]FIG. 3 is a side elevation view partially in section illustrating an embodiment of the tubing expander apparatus of the present inventions expanding a section of tubing;
[0010] [0010]FIG. 4 is a perspective view of the tool of FIG. 3;
[0011] [0011]FIG. 5 is a section view taken on line 5 - 5 of FIG. 3 looking in the direction of the arrows;
[0012] [0012]FIG. 6 is a detail view illustrating an embodiment of roller assembly configuration in the tool according to the present inventions;
[0013] [0013]FIG. 7 is a schematic section view of the tool illustrating the effective cross section formed by a set of rollers;
[0014] [0014]FIG. 8 is a schematic view similar to FIG. 7 illustrating another roller configuration according to the present inventions;
[0015] [0015]FIG. 9 is a schematic view similar to FIG. 7 illustrating yet another roller configuration according to the present inventions;
[0016] [0016]FIG. 10 is a schematic view similar to FIG. 7 illustrating a further roller configuration according to the present inventions;
[0017] [0017]FIG. 11 is a schematic elevation view of one configuration for a set of rollers according to the present inventions;
[0018] [0018]FIG. 12 is a schematic elevation view of another configuration for a set of rollers according to the present inventions;
[0019] [0019]FIG. 13 is a partial cross sectional view illustrating a tool embodiment according to the present inventions for retracting and expanding the rollers with the rollers illustrated in the expanded position;
[0020] [0020]FIG. 14 is a partial enlarged cross sectional view illustrating the a roller assembly in the retracted position according to the present inventions;
[0021] [0021]FIG. 15 is a cross sectional view similar to FIG. 13 illustrating the rollers in the expanded position;
[0022] [0022]FIG. 16 is a sectional view taken on line 16 - 16 of FIG. 15 looking in the direction of the arrows;
[0023] [0023]FIG. 17 is a partial cross sectional view illustrating another tool embodiment according to the present inventions for retracting and expanding the rollers with the rollers illustrated in the expanded position; and
[0024] [0024]FIG. 18 is a partial cross sectional view illustrating a further tool embodiment according to the present inventions for retracting and expanding the rollers with the rollers illustrated in the expanded position.
DETAILED DESCRIPTION
[0025] The present inventions are described by reference to drawings showing one or more examples of how the inventions can be made and used. In these drawings, reference characters are used throughout the several views to indicate like or corresponding parts.
[0026] In FIGS. 1 and 2, a subterranean portion of a well 10 , illustrated in section, has a cemented casing 12 terminating above an open hole 14 . Tubing connector 16 is illustrated at the casing end for supporting a tubing assembly 20 . A suitable collar 22 on the assembly 20 is designed to mate with the connector 16 . Although one system is illustrated for supporting the tubing assembly there are many other systems well known in the industry suitable for use with these inventions such as tubing hangers and the like. In the illustrated embodiment, the tubing assembly 20 comprises a tubular member 24 coupled at 26 to a tubular screen or perforated liner section. 28 . The illustrated tubing assembly is merely illustrative of many configurations of tubular members and the terms tubing assembly when used herein are generic an not intended to be limited to any particular assembly or types of tubular members and include combinations or pipe, screen, liners and the like with cylindrical, corrugated and other wall shapes.
[0027] In FIG. 1, tubing assembly 20 is illustrated being lowered through the casing 12 into the well 10 on a drill string (not shown). In FIG. 2 the tubing assembly is expanded to a full bore diameter using an expander tool constructed in accordance with the teachings of the present inventions.
[0028] In FIGS. 3 - 6 an embodiment of the expander tool 40 of the present invention is illustrated. In FIG. 3, the tool 40 is illustrated expanding a portion of tubing assembly 20 . Tool 40 has an elongated central body 42 connected to a drill string 44 by threads or the like. A plurality of tubing expander elements are longitudinally spaced on the body 42 . These expander elements include a guide head 50 and four sets of rollers 60 , 70 , 80 , and 90 . The tool 40 is designed to be forced down hole (in the direction of arrow “d”) by the weight of the drill string 44 . Alternatively, the expander could be pulled through the tubing assembly in the uphole direction.
[0029] Guide head 50 is sized to fit in the tubing assembly 20 . A plurality of axially extending ribs 52 engages the internal surface of the tubing assembly and centrally align the tool body 40 in the tubing. The downhole facing ends 54 of these ribs 52 are tapered to guide the head into the open end of the tubing. Since the roller sets perform the expansion steps, head 50 is preferably sized to act only as a guide with a small clearance with the internal surface of the tubing assembly. However, an interference fit is acceptable with some tubing deformation occurring before roller engagement. Although one guide head is shown in front of a roller set, it is envisioned that one or more guide heads could be used behind one or more roller sets to shape the tubing cross section. In addition, it is anticipated that a large number of smaller closely spaced roller assemblies could be used shape the tubing cross section after or during expansion.
[0030] Each of the roller sets 60 , 70 , 80 and 90 are typical in construction. Each has a plurality of roller assemblies 100 mounted to pivot about axis transverse to the length of the tubing assembly 20 . In the illustrated embodiment, each roller assembly comprises a shaft portion 102 and at least one endless tubing member contact surface 104 . In FIG. 6 the details of an embodiment of the roller assembly 100 are shown. Roller assembly 100 has a central shaft portion 102 and two spaced endless tubing contact surfaces 104 . Assembly 100 is symmetrical and designed to rotate about axis 106 . Axis 106 is aligned to be transverse to the tool and in a plane perpendicular to the center line 112 of the tubing assembly 20 . A lubrication fitting 108 connected to internal lubrication passageways 110 can be provided to supply lubrication to the surface of shaft 102 .
[0031] Contact surfaces 104 are profiled to match the expanded internal surface of tubing assembly 20 . This relationship is illustrated with surface 104 conforming to a cylindrical surface with a radius R measured from the tubing center line 112 , with the value of R being selected to match the expanded tubing member internal diameter. Alternatively, the roller assembly could be made with a single contact surface with a shaft on each side.
[0032] As can be seen in FIGS. 2, 3 and 5 each roller set contains a plurality of roller assemblies 100 spaced circumferentially about the tool body 42 with their out most surfaces arranged in a circle with a radius R larger than the unexpanded tubing assembly. For example, the roller set 60 could have a radius R an incremental amount larger than the internal diameter of the tubing assembly to be expanded. Roller sets 70 , 80 and 90 could each have a radius R slightly larger than the adjacent downhole roller set (to the left in the drawings) and would progressively expand the tubing as the tool 40 is forced through it by the string 44 . The endless contact surfaces 104 roll along the interior of the tubing preventing damage caused by friction forces generated using conventional expansion mandrels.
[0033] In FIG. 3, the typical mounting of one of the roller assemblies 100 of roller set 90 is shown. Shaft portion 102 engages a bearing portion 120 of a bracket 122 . Lifting tool 40 causes shaft 102 to retract out of contact with the tubing section and down ramp 124 of bracket 122 . Although, in this illustrated embodiment all roller assemblies utilize the ramp mounting to allow the roller to retract when the tool is lifted out of the well, it is envisioned that in some well configurations only the largest roller assembles would have the ability to retract.
[0034] In FIG. 7, a roller set is shown expanding a section of tubing 20 . As can be seen the expanded tubing 20 does not exactly conform to a circle, in that, the roller surfaces 104 contacting the interior of the tubing are spaced apart and are not a continuous circle. Effective cross section refers to the cross section shape of the interior of the tubing. The effective cross section has an effective radius R, effective cross sectional area A and effective circumference C. Unexpanded cylindrical tubing's effective cross section is circular. The effective cross section of expanded tubing is not necessarily completely circular.
[0035] As is illustrated in FIGS. 8 - 10 , the number of roller surfaces and their spacing has an effect on the shape of the effective cross section of the tubing 20 . In addition, the tubing material, thickness and amount of expansion would change the cross section shape. Preferably, the rollers are positioned so that their highest contact point is in a circle in the plane P-P as shown in FIG. 11. Plane P-P is transverse to the tool length and perpendicular to the tubing axis. In FIG. 12 another configuration is illustrated with the adjacent rollers 100 axially offset. In this configuration the roller contact points do not conform to a circle.
[0036] In the tool embodiment 140 illustrated in FIGS. 13 - 16 , the roller, assemblies can be retracted during run in and extended for the expansion step. In FIG. 13 tubing, assembly 20 is being expanded by tool assembly 140 as it is forced (pushed in downhole direction of arrow d by drill string 44 ) through the tubing from right to left in the figure. When using the retractable tool assembly 140 the drill string could also be connected to the tool 140 at the guide head 150 to force or pull the tool through the tubing assembly 20 in an up hole direction.
[0037] Tool assembly 140 (like tool 40 ) has a body 142 with a guide head 150 , and a plurality of roller sets 160 , 170 (not shown), 180 , and 190 carried thereon. The guide head and roller sets on tool assembly 140 function in the same manner as described with regard to tool 40 .
[0038] Tool 140 has cylindrical outer portion 146 defining a chamber 148 in which is mounted the means for extending and retracting the roller assemblies. Cylindrical portion 146 is illustrated as a single piece but it is fabricated (as is well known in the industry) in multiple pieces connected together by threads, pins, welding and the like. These connections are not shown for simplicity purposes.
[0039] A chamber 156 and piston 158 in portion 146 define a variable volume in fluid communication with the drill string through port 162 . By varying the fluid pressure in drill string 44 , piston 158 can be reciprocated axially in chamber 156 . In FIG. 13 pressure has been raised in chamber 156 causing piston 158 to move axially in the direction of arrow d against stop 164 .
[0040] An actuating rod 172 is mounted to axially reciprocate in a second chamber 174 in portion 146 . Rod 172 is connected to and is moved axially by piston 158 . When fluid pressure in chamber 156 moves piston 158 against stop 164 , coil spring 174 is compressed against wall 176 and rod 172 is moved into the chamber 156 . When pressure in chamber 156 is reduced spring 174 moves piston 158 toward the drill string 44 while moving rod 172 in the same direction. Rod 172 has a plurality of cam surfaces 178 which engage and move the roller assemblies into and out of the retracted and extended positions.
[0041] In FIGS. 13 - 16 , the interaction between the cam surface 178 on rod 172 and roller assemblies will be described. Roller assembly 200 is mounted on a bracket 222 similar to the non-retractable embodiment but with the roller shaft portion supported from a surface 224 which may be without the ramp, as illustrated, or may be ramped (see ramp surface 124 in FIG. 3). Cylindrical portion 146 has a plurality of axially extending slots 182 in its wall for receiving roller brackets 222 . Brackets 222 are designed to be movable with respect to portion 146 in and out of the slots 182 . A flange 184 (See FIG. 16) is larger in cross section than slot 182 and is connected to bracket 222 to restrict outward movement of the bracket 222 .
[0042] In FIG. 14 the roller assembly 200 is shown in the retracted position with the cam surface 178 is axially spaced from the flange 184 . When piston 158 moves the rod 178 from the FIG. 14 retracted position to the FIG. 15 extended position, cam surface 178 engages the flange 184 forcing the roller assembly 200 outward to the extended position. A leaf spring 186 urges the bracket 222 toward the retracted position and when the rod 172 is moved out of contact with the flange 184 , the roller assembly will retract.
[0043] In FIG. 17 another roller assembly 300 embodiment is illustrated in solid line extended and in dotted lines retracted. Roller bracket 322 is pivoted from tool body 342 on shaft 344 . The roller assembly rotates in the directions of arrow E about axis 344 from the retracted position shown in dotted lines to the extended position shown in solid lines. A slot 346 can be formed in body 342 to allow the bracket to pivot into the body 342 . A stop similar to stop 164 can be provided to limit outward rotation. An actuating rod 372 is moved axially in the direction of arrow d in body 342 by the previously described piston chamber assembly to engage the bracket with cam surface 378 to extend the bracket 322 . When the rod 372 is retracted a suitable spring 348 causes the bracket to rotate to the retracted position.
[0044] In FIG. 18 a further embodiment of a retractable roller assembly 400 is illustrated in solid lines in the retracted position and in dotted lines in the extended position. In this embodiment the bracket 422 is fixed to the exterior of the body 442 . Bracket 422 has an outwardly inclined ramp surface 424 supporting roller shaft 402 . As the tool body 442 is moved down holed (arrow d) contact between the roller and the tubing assembly will tend to cause the roller shaft 402 to climb the ramp 424 and move to the extended position shown in dotted lines. However, during movement of the tool into position, a releasable latch shown here in the form of a pin 444 holding the shaft 402 in the retracted position (solid lines) at the bottom of the ramp 424 . Pin 444 is biased by compression spring 446 to move in the direction of arrow X out of the path of shaft 402 . Once tool body 442 is in position in the well, the actuating rod 472 is moved axially from under pin 444 allowing spring 446 to retract the pin down out of contact with the shaft 402 . With pin 444 retracted, downward movement (direction of arrow d) of the tool will allow shaft 402 to climb ramp 424 to the extended position to perform the tubing assembly expanding step. Once expansion is completed lifting up on the tool body 442 will cause the roller to move down ramp 424 to the retracted position. In addition, the actuating shaft 472 can be moved downward by a cylinder-piston assembly (not shown) until cam surface 478 engages pin 444 and returns it to the locking position shown in FIG. 18.
[0045] According to the present inventions the wellbore is completed through a series of steps. First, a tubing assembly is provided comprising at least in part an expandable tubular member. The tubular assembly can be a continuous tubular member, or a liner with drainage openings and/or screen. Either before or after any required perforation steps, the tubing assembly is positioned in the well where it is to be expanded. Once in the desired position, the tubing assembly is radially expanded by engaging it with an expander tool having sets of rollers positioned on the tool to progressively expand the tubing assembly as the tool is moved through the tubular assembly. In the extendable tool embodiment, the tool is moved to a position adjacent the tubular member in the retracted condition and expands the tubular member while in the radially extended condition. Thereafter the tool can be retracted and moved out of the well.
[0046] The embodiments shown and described above are only exemplary. Many details are often found in the art such as: actuator pistons and cylinders, expandable tubing, expandable liners, and expandable screens and the like. Therefore, many such details are neither shown nor described. It is not claimed that all of the detail parts, elements, or steps described and shown were invented herein. It is also envisioned that a conventional chemical powered setting tool or the like could operate the extendable tool. Even though numerous characteristics and advantages of the present inventions have been set forth in the foregoing description, together with details of the structure and function of the inventions, the disclosure is illustrative only, and changes may be made in the detail, especially in matters of shape, size and arrangement of the parts within the principles of the inventions to the full extent indicated by the broad general meaning of the terms used the attached claims.
[0047] The restrictive description and drawings of the specific examples above do not point out what an infringement of this patent would be, but are to provide at least one explanation of how to make and use the inventions. The limits of the inventions and the bounds of the patent protection are measured by and defined in the following claims: | Disclosed is an improved apparatus and method for completing a wellbore using radially expandable tubing. An expanding tool is used with sets of rollers positioned to progressively expand the tubing by rolling along the interior of the tubing. | 4 |
BACKGROUND OF THE INVENTION
At the present time many people operate keyboards, such as computer keyboards, word processor keyboards and typewriter keyboards. It is often the situation that, whilst operating the keyboard, the operator has to read a piece of paper.
The present invention seeks to provide a holder which can be readily utilised to hold a piece of paper in such a position that it can be readily viewed by a person operating a keyboard, but it is to be understood that embodiments of the invention may be utilised for other purposes.
It has been propsed previously to provide a holder for a piece of paper, to hold the piece of paper in a position where the piece of paper can be viewed by a person operating a keyboard, and one typical holder of this type consists of an arcuate support plate which is associated with a flexible transparent arcuate strip which can move from a position in which it is located in a bowed position biassed towards the arcuate support plate, through a dead centre position to a second position in which it is bowed away from the arcuate support plate. Thus a piece of paper may be located adjacent the arcuate support plate when the t,ransparent strip is in the second position bowed away from the support plate, and then the arcuate strip many be snapped through the dead centre position, thus trapping the piece of paper and holding it in position. However, in utilising a device of this type it is necessary to use two hands in order to place the paper in position. Also the device is relatively expensive to produce.
BRIEF SUMMARY OF THE INVENTION
According to this invention there is provided a paper holder, said paper holder comprising an elongate member, said elongate member defining therein a slot, said slot being non-linear in at least one dimension, and means adapted to mount said member in position with the slotted portion projecting so that a sheet of paper may be inserted in said slot.
Preferably said slot is arcuate in at least one dimension.
Conveniently said slot is arcuate in two dimensions.
Advantageously said slot terminates with a curved portion leading to an open mouth, the mouth being wider than the width of the slot.
Preferably siad member is formed of a moulded plastic material.
Conveniently the paper holder is formed of ABS or an acrylic plastic material.
In one embodiment said elongate member defines two said slots, the slots being disposed at opposite ends of the elongate member, the elongate member being of symmetrical design.
In an alternative embodiment the elongate member is telescopically received within a housing, means being provided to retain the elongate member in a retracted position in which it is substantially contained within the housing and an extended position in which it substantially projects from said housing.
Preferably the end of the elongate member adjacent the end of the slot is provided with ribbing or the like and projects beyond one end of said housing.
Conveniently the other end of said elongate member is bifurcated, the bifurcated poritons defining means adapted to cooperate with corresponding means formed on the side walls of the housing to perform the said function of retaining the elongate member in the retracted position and in the extending position.
Advantageously each bifurcation defines thereon a recess, and the side walls of the housing define two opposed pairs of projections adapted to engage said recesses to constitute the said retaining means.
In another embodiment the elongate member is rotatably mounted on a support.
Preferably the said elongate member defines an aperture adjacent one end thereof, there being a threaded plug passed through said aperture and into a threaded bore on said support to rotatably mount the elongate member in the support.
Conveniently the means to mount said member in position comprise double sided adhesive tape.
BRIEF INTRODUCTION OF THE DRAWING
FIG. 1 is a plan view of one embodiment of a paper holder in accordance with the invention;
FIG. 2 is a top view, partly cut away of a second embodiment of a paper holder,
FIG. 3 is a view, in perspective, showing the second embodiment ready for use,
FIG. 4 is a sectional view taken on the line IV--IV of FIG. 2,
FIG. 5 is an enlarged view of part of FIG. 2,
FIG. 6 is an enlarged view showing part of the apparatus of FIG. 2 in an alternative position,
FIG. 7 is a plan view of a third embodiment of the invention, and
FIG. 8 is an exploded view of the third embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring initially to FIG. 1 a paper holder in accordance with the invention consists of an elongate integrally moulded plastics material member 1. As will become apparent from the following description, the member is symmetrical and effectively comprises two paper holders formed as one component.
The central part 2 of the elongate member may be secured to a visual display unit, for example by means of an adhesive. It is envisaged that double-sided adhesive tape may be sued for this purpose. One part of the member 1 will hang over the edge of the visual display unit.
The elongate member 1 is provided, at each end, with a double arcuate slot 3. The double arcuate slot is of an arcuate configuration in two planes. As can be seen, when the slot is viewed from above the slot is of arcuate form 4, 5. The slot 3 thus has two terminal arcuate portions 4, 5 interconnected by a linear portion. However, the slot may have any desired nonlinear form. The surving arcuate slot 3 emerges at a mouth 6 formed in one side edge of the elongate member. The slot 3 itself is arcuate 4, 5 in the vertical sense. That is to say the slot 3 has a curved configuration, the tangent to that curve lying in the plane of the elongate member 1. However, the slot is also arcuate in the vertical plane. Thus the cross-section of the slot is arcuate and the tangent to the arcuate cross-section is a line peripendicular to the plane of the elongate member 1. Thus the slot is double arcuate, being arcuate relative to two planes.
The paper holder, described above may be fabricated from any appropriate material, and may thus, for example, be moulded from ABS or an acrylic material.
In use, the paper holder 1 is mounted in position, for example on top of a visual display unit with a part carrying one slot 3 extending beyond the visual display unit. A sheet of paper may then have one edge thereof introduced into the slot, and as the paper is pushed fully into the slot the paper will be bent in two planes because of the fact that the slot is arcuate in two planes. This bending of the paper tends to stiffen the paper, and thus, although only part of the paper is accommodated within the slot, the sheet of paper is held in a substantially stiff and erect positoin. Again, because of the double arcuate nature of the slot, the paper is retained in position, although the paper can be moved relative to the paper holder by applying a firm pull to the paper.
It will thus be appreciated that the described embodiment of the invention may be utilised to hold a sheet of paper in a position where the paper is readily visible to a person operating a keyboard associated with the visual display unit.
The described device is made with two slots 3, so that the device may be mounted either to over hang the right hand side of the visual display unit, or may be utilised to overhang the left hand side of a visual display unit. However, it is to be appreciated that alternatively the device may only have one slot, the device then being reversible, the device being mounted in one position with the slot overhanging one side of the visual display unit or being rotated and inverted so that the slot hangs over the other side of the visual display unit.
Any appropriate means may be provided for mounting the paper holder in position and, indeed, the paper holder 1, or a corresponding paper holder having only one slot, may be mounted in position on a freestanding support.
Whilst the invention has been described with reference to a paper holding device being mounted on a visual display unit it is to be appreciated that the paper holding device may alternatively be mounted on a wordprocessor keyboard or on a typewriter. Indeed, the device may be mounted in positon on any suitable support.
Referring now to FIGS. 2 to 6 of the accompanying is illustrated in which an elongate member 10 is provided with an arcuate slot 13 having an open mouth 16. One free end of the member, adjacent the open mouth 16, is provided with ribs or knurling 18. The other end is provided with a bifurcated poriton 19, 20, the exterior surfaces of the bifurcated poriton defining vertically extending recesses 21, 22. The described elongate member 10 is telescopically mounted within a rectangular cross-sectioned tubular member 23. The member 23 has, adjacent each end, opposed pairs of ribs 24, 25, formed in the side walls of the housing. It can be seen, from FIG. 6, that the recesses 21, 22 formed in the bifurcated part engage one pair of ribs 24, 25.
The slot is arcuate in two planes, having arcuate poritons 14, 15 in the horizontal plane, and having an arcuate cross-section 12 (as can be seen from FIG. 4) in the vertical plane.
It will be apprecitaed that, when the ribbed portion 18 of the elongate member 10 is grasped manually and is pulled, the bifurcations 19, 20 will be biassed to move towards one another by the camming action provided by the cooperation between the ribs 24, 25 and the recesses 21, 22. Thus the bifurcations 19, 20 will move inwardly permitting the elongate member 10 to move telescopically within the tubular housing 23. The bifurcations will again move resiliently inwardly when they approach the other pair of ribs 24, 25 and the bifurcations will resiliently move outwardly when the recesses 21, 22 are aligned with this second pair of ribs 24, 25. Thus the elongate member will be "snapped" into a position in which it is protruding from the housing 23, as shown in FIGS. 3 and 6, and is firmly retained in position by means of the engagement between the ribs 24, 25 and the recesses 21, 22.
It is to be appreciated that firm inward pressure applied to the ribbed end 18 of the elongate member 10 will return the elongate member 10 to its initial position, where again it will be "snapped" into position, as shown in FIGS. 2 and 5. A stop 26 formed on the elongate member 10 will engage the housing 23.
It is envisaged that the housing 23 will be mounted in position on a visual display unit, 27 as shown in FIG. 3 or on a typewriter, word processor keyboard or the like, and the elongate member may be moved between its retracted position, in which it projects beyond the housing 23, and an alternative, or storage position, in which it is retained within the housing 23. As is shown, the elongate member may overhang to the right, but as shown in phantom may alternatively overhang to the left.
It will be readily understood that when the member 10 is in the extended position the slot 13 is accessible, and a sheet of paper may be inserted into the slot 13 through the mouth 16 in a manner corresponding to that described above with reference to FIG. 1.
The housing 23 may be adhered to any appropriate surface in any appropriate orientation. If the housing 23 is adhered to a support which, at the end of a working day, is covered up with a cover, the elongate member 10 may be moved telescopically to its retracted position before the cover is placed in position.
FIGS. 7 and 8 illustrate yet another embodiment of the invention in which an elongate member 30, having a double arcuate slot 33 with an open mouth 36, is provided with an aperture 34 at the end remote from the mouth. The slot 33 has a configuration corresponding to that of the slots described above. A threaded plug 38 may pass through the aperture 34 to rotatably mount the elongate member 30 on a suport 40. The support 40 has a threaded bore 41 to receive a threaded part 42 of the plug, and a non-threaded part 43 of the plug is received within the aperture 34 to rotatably support the elongate member. The support 40 may be secured to any convenient support surface and thus the elongate member may be rotated to any desired position.
It will be observed that the support 40 has two corresponding threaded holes 41, one at each end, to enable the device to cantilever over the left hand edge or the right hand edge of a support surface. The hole 41 that is not in use is provided with a cover 44.
Whilst the invention has been described with reference to exemplary embodiments it is to be appreciated that many further modifications may be effected without departing from the scope of the invention.
It is to be understood that the invention has only been described by way of example, and many modified embodiments of the inveniton may be devised within the scope of the inveniton as defined by the following claims. | A paper holder, for holding paper for the operator of a key board, for example, consists of an elongate member defining a slot, the slot being non-linear and at least one dimension. A piece of paper may be inserted into the slotted member, the piece of paper being held in a stiff erect position. | 1 |
TECHNICAL FIELD
[0001] This invention relates to seals for fluid containers and, more particularly, to containers with open gaps having a wide gap tolerance and seals adapted therefor.
BACKGROUND OF THE INVENTION
[0002] It is known in the art relating to fluid container seals that for long term life, a resilient seal material has a limited range of compression within which it may be expected to provide an effective seal over a maximum lifetime. If the seal is under compressed, its sealing effectiveness may be compromised. However, if the material is over compressed, conditions of heat and exposure to fluids such as oil, may significantly impact the ability of the seal to perform its intended function.
[0003] Designing seals for joints where two machined surfaces are maintained in direct engagement with one another is relatively simple. A groove is provided in one of the surfaces for receiving the seal, which is designed with a length of extension beyond the depth of the groove so that upon engagement of the surfaces to be sealed, compression of the seal material will fall within the desired compression range for maximum life. However, in some applications of seals in fluid containers the tolerances of the components to be sealed together are too large to allow direct contact between the sealing surfaces.
[0004] One example is a rocker cover for an automotive engine wherein, for noise isolation purposes, the rocker cover and the associated cylinder head or manifold, have a gap by design between the sealed surfaces which varies significantly from a condition of maximum stack-up or tolerances creating a wider gap and a minimum stack-up or tolerances creating a smaller gap. This situation may be compounded by a limit on the depth of the groove, which is provided in one of the components for supporting a generally rectangular seal in the groove and extending therebeyond. If such a seal extends beyond the supporting portion of the groove by an excessive length, the unsupported portion of the seal will buckle when compressed, resulting in inadequate compression or rotating in the groove, which leads to unsatisfactory seal performance.
SUMMARY OF THE INVENTION
[0005] The present invention provides supplemental support by the addition of two symmetrical barb-like projections that make contact outside of the retaining groove for an otherwise unsupported rectangular portion of a seal that extends beyond the retaining groove formed in one member of a container assembly. By providing this supplemental support, the seal is able to be extended a greater distance so as to close a larger gap than would be possible with a typical rectangular seal configuration. Accordingly, larger differences in the stack up gap or tolerances of the assembly may be accommodated by a molded seal acting within its ideal limits of compression.
[0006] We have learned that with a conventional rectangular seal, the unsupported seal height beyond the groove should not be more than about 1.5 times the supported seal height within the groove. Otherwise, the seal will buckle when compressed unless some additional support is provided for the portion of the seal height which extends beyond the supporting length of the groove in which the seal is retained.
[0007] In a preferred embodiment, a seal according to the invention includes a linearly extending resilient seal body with a cross-sectional configuration including a generally rectangular central section of greater height than width and having first and second sealing edges at opposite ends of the height dimension. The central section includes first and second compressible portions extending inward from the first and second sealing edges and which represent the supported and unsupported portions of the seal.
[0008] Accordingly, the first compressible portion includes generally parallel sides which are adapted to be supported in a groove in a seal surface of one component of the assembly, wherein the first sealing edge engages the bottom of the groove for sealing the groove against fluid passage across the groove. The second compressible portion includes sides which carry resilient stabilizers, also of the same compressible material. The stabilizers are angled outward from the second sealing edge which is adapted to engage a flat surface of the other member of the container assembly. The stabilizers terminate in barb-like projections that are engageable with a flat portion of the grooved surface adjacent to the groove.
[0009] Upon compression of the seal, the stabilizers are compressed against the flat surface adjacent the groove of the grooved surface. The stabilizers are designed to resiliently yield as they provide support for the second compressible portion of the central section to prevent it from buckling while the seal is compressed to within its desired range of compression. The seal compression takes place over the entire seal height, from the first sealing edge engaging the bottom of the groove to the second sealing edge engaging the flat portion of the opposing surface of the joint.
[0010] An additional advantage of a seal according to the invention is that the resilient stabilizers, by their contact with the seal surface adjacent to the groove, help shield the seal against the entry of fluid or debris into the groove and thus help prolong seal life. This is especially advantageous when the seal groove is formed in a lower member of a container.
[0011] These and other features and advantages of the invention will be more fully understood from the following description of certain specific embodiments of the invention taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a cross-sectional view through a representative seal according to the invention having nominal dimensions and shown uncompressed between associated opposed sealing surfaces.
[0013] [0013]FIG. 2 is an isometric view of the seal of FIG. 1 showing the linearly extending body of the externally supported seal.
[0014] [0014]FIG. 3 is a cross-sectional view similar to FIG. 1 but showing the seal in the compressed condition.
[0015] [0015]FIG. 4 is a view similar to FIG. 1 through a retention portion of the seal and showing the seal in a minimum compression position.
[0016] [0016]FIG. 5 is a view similar to FIG. 4 but showing the seal in a maximum compression position.
[0017] [0017]FIG. 6 is a cross-sectional view of a similar seal in position between a crankshaft bearing cap and an associated oil pan half-round opening.
[0018] [0018]FIG. 7 is a pictorial view illustrating application of the seal of FIG. 6 in an engine application.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] Referring first to FIG. 1 of the drawings in detail, numeral 10 generally indicates a nominal cross-sectional configuration of a linearly extending wide tolerance fluid seal according to the invention. The seal 10 is shown positioned between upper and lower components 12 , 14 having opposed sealing surfaces 16 , 18 . The upper sealing surface 16 includes a groove 20 in which the seal 10 is retained as shown in a fully uncompressed condition. A linear dimension 22 between the surfaces 16 , 18 represents a gap between the surfaces, the width of the gap being subsequently reduced upon completion of the assembly of components 12 and 14 with the seal in a compressed position.
[0020] [0020]FIG. 2 is an isometric view illustrating a portion of the linearly extending body 23 of the seal 10 . The body 23 is molded from a resilient seal material suitable for a particular seal application wherein the seal configuration and material are capable of satisfactory sealing of a fluid with a compression of the seal in the range of from about 20% to 35% of the total seal height.
[0021] In the uncompressed position as viewed in FIG. 1, the cross-sectional configuration of the seal includes a generally rectangular central section 24 . The central section, as uncompressed, has a height 26 which is substantially greater than its width 28 . First and second sealing edges 30 , 32 are provided at opposite ends of the height dimension of the central section, which is divided, as an aid to description, into first and second compressible portions 34 , 36 . These extend inward toward one another from the first and second sealing edges 30 , 32 , respectively. The sealing edges 30 , 32 are preferably formed by tapered opposite ends of the central section at 45° angles from contact points 38 at the tips of the opposite ends of the central portion.
[0022] The first compressible portion 34 , which is the upper portion as shown in FIG. 1, includes generally parallel sides 40 for reception within the groove 20 of component 12 . The sides 40 also include the typical longitudinally spaced barrel-like extensions 42 , shown in FIGS. 2 and 4, which are provided for the purposed of retaining the seal in the groove prior to installation in an assembly.
[0023] The second compressible portion or lower portion 36 of the central section 24 also includes sides 44 on which are carried resilient stabilizers 46 . These angle outward and upward from the second sealing edge 32 and terminate in barb-like resilient projections 48 formed of the molded resilient material of the seal.
[0024] As subsequently described, the nominal dimensional relationships of the seal 10 and the associated sealing surfaces 52 , 18 are exemplary only and not to be considered limiting as to the specific seal configuration for a particular application. FIG. 1 indicates the following nominal relationships. The width 28 (Wc) of the central section 24 is approximately 75% of the width (Wg) of the groove 20 . Similarly, the nominal width 50 (Wp) of the resilient projections 48 is approximately 75% of the uncompressed height 26 (H) of the seal.
[0025] Dimension 22 a represents the width of the gap 22 when the seal has been compressed to 20% of its free height 26 (H), representing, in this case, a recommended minimum compression for adequate sealing. Dimension 22 b represents the width of the gap 22 when the seal has been further compressed to 35% of its uncompressed height 26 (H), which represents, in this case, the maximum recommended compression of the seal for long life operation of the seal in the compressed condition. Also noted is that the supporting depth of the groove 20 is the dimension, not indicated, from the bottom 52 of the groove to the upper edge of the chamfers 54 provided between the sides of the groove 20 and the flat sealing surface 16 of the upper component 12 .
[0026] Referring now to FIG. 3, there is illustrated the cross-sectional configuration of seal 10 in the fully compressed condition indicated by dimension 22 b of FIG. 1. In this fully compressed condition, the resilient projections 48 of the stabilizers 46 have been deflected downward and outward so as to fully engage the lower surface 16 of the upper component 12 . At the same time, the center section 24 of the seal 10 has been compressed to the maximum 35% compression condition. This causes the sealing edges 30 , 32 to engage the bottom 52 of groove 20 and the opposite sealing surface 18 of the lower component 14 with a maximum sealing pressure or force that is effective to prevent the leakage of fluid past the seal through the gap 22 .
[0027] The resilient stabilizers 46 do not perform a substantial sealing function in the compressed condition. However, they do exert stabilizing forces on the lower portion, or second compressible portion 36 of the central section 24 , which prevents this portion 36 from buckling under the compression load. Without this stabilizing force, the lower, or second compressible portion 36 , would buckle if it were not supported for a length which is greater than about 1.5 times of the length of the supported portion from the bottom of the groove 20 to the top of the chamfer 54 .
[0028] Note that in the compressed condition, the upper portion or first compressible portion 34 of the central section 24 is forced up into the groove and expands to nearly the width of the groove. Further it is noted that the shape of the resilient projections 48 of stabilizers 46 is carefully controlled so that these extensions supply only a limited force against the upper sealing surface 16 . They therefore have a minimum effect on the compression of the central section of the seal which is relied upon completely for providing the sealing function between the lower surface 18 and the bottom 52 of the groove 20 .
[0029] Referring now to FIG. 4, there is illustrated a cross-sectional configuration of the seal 10 illustrating the barrel-like projections 42 which engage the sides of the groove 20 and retain the seal within the groove before the seal is compressed in a component assembly as part of a fluid container. As shown in FIG. 4, the seal 10 has been compressed to its minimum compression level of 20% as indicated by dimension 22 a . At this point, the stabilizer projections 48 are stabilizing the central section 24 against buckling by engaging with the projections 48 the lower surface 16 of the upper component 12 .
[0030] Again, the resilient force of the projections 48 on the upper component is limited to that necessary to maintain the lower portion 36 of the central section in alignment and avoid buckling. Thus, operation of the stabilizers 46 does not adversely affect the compression function of the seal between the bottom 52 of the groove 20 and the sealing surface 18 of the lower component.
[0031] [0031]FIG. 5 similarly illustrates the fully compressed seal 10 in the cross section illustrated in FIG. 4. In this the stabilizer projections are fully extended as shown also in FIG. 3.
[0032] In order to determine the requirements for a seal of this type, a formula is proposed for determining the required seal height for a particular application in which the possible depth of the groove is limited and the tolerance of the parts results in a wide variation in the possible gap between the opposing seal engaging surfaces. The formula may be expressed in words as:
[0033] the uncompressed seal height equals the clearance variation of the assembly surfaces plus twice the seal profile tolerance divided by the compression range of the seal material.
[0034] Alternatively in mathematical form, the formula is:
H = A - B + 2 C U C - L C
[0035] where:
[0036] H 32 total seal height
[0037] A=maximum stack up-gap (at maximum tolerances)
[0038] B=minimum stack-up gap (at minimum tolerances)
[0039] C=the seal profile tolerance
[0040] Uc=the upper compression limit in percent and
[0041] Lc=the lower compression limit in percent.
[0042] The result of the calculation yields the nominal height H of the seal which can be used in an assembly to cover the complete range of stack-up gap or tolerance variations designed into the components. From the seal height (H) and the groove depth, the range of gaps required between the part surfaces may be calculated and the need for providing an externally supported seal in accordance with the invention may be determined.
[0043] The previously described embodiment represents a seal arrangement developed in particular for use in sealing a rocker cover on an automotive engine. However, essentially the same general configuration can be utilized in any suitable application for sealing gaps between fluid containers where a relatively wide tolerance leads to a significant variation in maximum and minimum gap figures for a sealed container assembly. Following is a second example wherein a seal according to the invention was developed for application to the gap between an engine crankshaft rear bearing cap and an associated oil pan semicircular cutout opposing the exterior of the crankshaft bearing cap.
[0044] In applying the invention to the oil pan design, it was found necessary to increase the gap between the sealing surfaces of the oil pan and the associated crankshaft rear bearing cap and front cover by an amount sufficient to allow for the relatively large tolerances on the parts to be accommodated and still remain within the range of seal compression which was allowed.
[0045] In order to accommodate the stack up tolerances, a substantial increase in the cross-sectional length of the seal was required, which then resulted in an extension of the seal beyond the groove to a dimension that exceeded the buckling factor by extending more than 1.5 times the length of the supported portion within the associated groove. As a result, application of the seal cross section of the present invention including the resilient stabilizers was utilized to support the otherwise unsupported portion of the seal and prevent it from buckling under compressive loads.
[0046] Referring to FIG. 6, numeral 60 generally indicates a portion of the oil pan and seal assembly according to the invention. Assembly 60 includes an oil pan flange 62 having a half round sealing surface 64 with a central groove 66 . A linear seal 68 includes a central section 70 of generally rectangular configuration and having a first compressible portion 72 which is received within the groove 66 . In this design, the first compressible portion 72 forms the lower portion of the seal 60 . An upper seal portion includes a second compressible portion 74 that extends upward above the sealing surface 64 .
[0047] As in the previous embodiment, the second compressible portion includes resilient stabilizers 76 extending from sides of the second compressible portion and angling outward and downward to terminate in resilient barb-like protrusions 78 , the tips of which engage the sealing surface 64 . FIG. 6 illustrates the assembly in the uncompressed condition of the seal 68 .
[0048] [0048]FIG. 7 shows a pictorial view of the seal assembly 60 in the assembled condition wherein the seal 68 is fully compressed with the resilient projections 78 flared out and flattened against the flange sealing surface 64 of the oil pan. The seal 68 includes a first sealing edge 80 that is flattened against the bottom of the groove 66 and a second sealing edge 82 that is flattened against a sealing surface 84 of the crankshaft bearing cap 86 .
[0049] The configuration of the developed seal generally follows the form of the seal developed for the rocker cover application but is adjusted to suit the particular conditions of the application. For example, adjustment of the length of the supporting barb-like projections 78 may be required in order to avoid these supporting projections from extending beyond the width of the opposing seal surfaces of the assembly and thus opening the possibility of undesirable contact with other moving components of the engine.
[0050] In addition to the primary advantage of the resilient projections 78 and 48 provided for use in the exemplary seal embodiments just discussed, an additional advantage is that engagement of these seal projections with the associated seal surface on either sides of the groove provides an impediment to the leakage of fluids into the groove, particularly in the oil pan application, and to the migration of external debris into the other side of the groove from the portion of the seal which is exposed to ambient conditions outside of the container, in this case an oil pan or a rocker cover.
[0051] While the invention has been described by reference to certain preferred embodiments, it should be understood that numerous changes could be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the disclosed embodiments, but that it have the full scope permitted by the language of the following claims. | A fluid container assembly design has a wide tolerance variation in the width of an open seal gap between opposed sealing surfaces of different assemblies. A resilient seal is provided with a generally rectangular central section partially supported within a groove and partially unsupported by excessive extension beyond the groove. To avoid buckling, the extending portion includes resilient stabilizers including barb-like projections. These resiliently engage a component surface adjacent the groove to stabilize the extending portion and prevent buckling. This allows the seal to compress over its total height to seal the gap between the bottom of the retaining groove in one component and the opposite sealing surface of the other assembly component while the stabilizer projections yield to avoid involvement in the sealing function and act only to prevent buckling of the seal unsupported portion. Exemplary applications for engine rocker covers and oil pan-crankshaft seal gaps are disclosed. | 5 |
The present invention relates to a powered accessory, such as a dust collection system for a hand held cordless power tool, such as a drilling and/or hammering tool. In particular the present invention relates to a system of a cordless drilling and/or hammering tool, a battery pack for powering the tool and an accessory unit, such as a dust collection unit for collecting dust generated by the tool. The present invention also relates to an accessory unit for use in such a system.
BACKGROUND OF THE INVENTION
Hand held drilling and/or hammering tools are known in the art which are powered by a battery pack instead of by a mains or generator source via a cord or cable. Such battery packs are generally rechargeable and house a plurality of electrical rechargeable cells. When the battery pack is mounted on the tool a releaseable mechanical connection is formed to secure the battery pack to the tool and an electrical connection is formed to supply electrical current from the cells to the motor of the battery pack. The battery pack is periodically removed from the tool so that is can be recharged by connection to a battery charger.
Hand held drilling and/or hammering tools are also know which can be used with a dust collection unit accessory. The collection unit, may be releaseably mechanically mounted on the tool and will generally comprise a shroud for collecting dust from the region of a tool or bit of the tool, a dust collection chamber, a filter and a system for generating an airflow into and through the shroud, through the chamber and the filter. Dust and debris generated by the tool or bit of the tool will be entrained in this airflow and so will be pulled into the shroud and into the chamber. As the air passes through the filter, any dust or debris entrained within it will be deposited in the chamber.
Both the dust collection unit and battery pack can be bulky and heavy and for a dust collection accessory for a cordless tool, both require connection to the tool.
BRIEF SUMMARY OF THE INVENTION
The present invention aims to provide an efficient accessory system for a hand held cordless power tool, which has optimum performance, is flexible and ergonomic.
According to a first aspect of the present invention there is provided an accessory system of a cordless hand held power tool, comprising:
the tool; an accessory unit ( 40 ) comprising a separate motor for powering the unit and releasably mountable on the tool; and a battery pack ( 4 ); characterised in that the battery pack can be mounted on the accessory unit for powering the accessory unit and, when the accessory unit is mounted on the tool, for powering the tool via the accessory unit.
By using a separate motor (separate from the motor of the tool) for powering the accessory unit, optimum performance of the accessory unit can be achieved, independent of the performance characteristics of the motor of the tool. The system according to the present invention also provides a flexible and ergonomic system for powering the tool and/or the accessory unit. The battery pack can be releasably mounted on the tool or can be separately releasably mounted on the accessory unit, so as to power the tool only when the accessory unit is not required or so as to power the tool and the accessory unit attached to the tool, when the accessory is required.
The tool will generally include a switch for actuating the motor of the tool and this switch may be arranged such that when the battery pack is mounted on the accessory unit and when the accessory unit is mounted on the tool, depression of the switch actuates power supply to the motor of the tool and to the motor of the accessory unit. Alternatively, the accessory unit may be actuated by a separate switch on the unit.
According to a preferred embodiment the tool may comprise a common mechanical and electrical interface via which the battery pack can be mounted on and electrically connected to the hammer or via which the accessory unit can be mounted on and electrically connected to the hammer. Similarly, the battery pack preferably comprises a common mechanical and electrical interface via which it can be mounted on and electrically connected to the accessory unit or via which it can be mounted on and electrically connected to the tool. The mechanical and electrical interfaces may advantageously comprise a rail and groove connection and a releaseable latch arrangement.
In a preferred embodiment, the accessory unit may comprises a first electrical and mechanical interface, via which it can be mounted on and electrically connected to the tool, a second electrical and mechanical interface, via which it can be mounted on and electrically connected to the battery pack, and an electrical connection between the first and second interfaces, via which electrical current is passed from the battery pack to the tool, when the accessory unit is mounted on the tool and the battery pack is mounted on the accessory unit.
The accessory unit may be a dust collection unit for collecting dust generated by the operation of the tool.
In a preferred embodiment, the dust collection unit includes a fan and the motor of the unit powers the fan so as to generate an optimum dust collecting airflow, independent of the speed of the motor of the tool. Such a dust collection unit may comprise a shroud for collecting dust from the vicinity of a tool or bit of the tool, which shroud communicates with a filter housing, incorporating a filter, such that an airflow generated by the fan passes into the shroud, into the filter housing and then into the fan.
The battery pack may be mounted on the tool from a first direction with respect to a longitudinal axis of the tool and may be mounted on the accessory unit, when the accessory unit is mounted on the tool, from a second different direction with respect to the axis.
According to a second aspect of the present invention there is provided an accessory unit for a cordless hand held power tool which is releasably mountable on such a tool and comprises a separate motor for powering the unit, characterised in that the accessory unit comprises a first interface via which it can be mechanically and electrically connected to such a tool and a second interface via which it can be mechanically and electrically connected to a battery pack, which battery pack is for powering the motor of the accessory unit and, when the accessory unit is mounted on such a tool, for powering such a tool via the accessory unit. Again, the motor of the accessory unit may be actuated when a tool to which the accessory unit is mounted is actuated. Also, the accessory unit may be a dust collecting unit as described above.
In order to power the tool from the battery pack via the dust collection unit, the accessory unit may advantageously comprise an electrical connection between the first and second interfaces, via which electrical current is passed from a battery pack to a tool, when the accessory unit is mounted on a tool and a battery pack is mounted on the accessory unit.
BRIEF DESCRIPTION OF THE DRAWINGS
One form of cordless rotary hammer incorporating dust collection system according to the present invention will now be described by way of example with reference to the accompanying drawings in which:
FIG. 1 shows a perspective view of a cordless rotary hammer in accordance with the present invention with a battery pack fitted to it;
FIG. 2 shows a perspective view of the cordless rotary hammer of FIG. 1 with the battery pack detached from it;
FIG. 3A shows a rear perspective view of the battery pack of FIGS. 1 and 2 ;
FIG. 3B shows a front perspective view of the battery pack of FIGS. 1 and 2 ;
FIG. 4 shows a perspective view of a dust collection unit for the rotary hammer of FIG. 1 in accordance with the present invention;
FIG. 5 shows a perspective view of the dust collection unit of FIG. 4 with the battery pack of FIGS. 1 to 3B fitted to it;
FIG. 6 shows a perspective view of the rotary hammer of FIG. 2 with the dust collection unit and battery pack sub-assembly of FIG. 5 fitted to it; and
FIG. 7 shows a circuit diagram of the wiring between the rotary hammer of FIG. 1 , the dust extraction unit of FIG. 4 and the battery pack of FIGS. 3A and 3B with the battery pack fitted to the dust extraction unit and the dust extraction unit fitted to the rotary hammer, as shown in FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
The hand held cordless rotary hammer shown in the Figures has a housing comprising a motor housing portion ( 2 ) within which an electric motor ( 3 ) of the hammer is housed. A tool holder ( 26 ) is located at the forward end of a spindle of the hammer. A tool or bit ( 24 ) can be non-rotatably and releasably fitted within the tool holder so as to allow limited reciprocation of the tool or bit with respect to the tool holder. The hammer has a rear handle ( 18 ) in which an on/off trigger ( 20 ) is located for actuating a switch for actuating power supply to the motor ( 3 ). The motor of the hammer selectively drives a spindle drive mechanism for rotatingly driving the spindle of the hammer, thereby rotatingly driving the tool holder ( 26 ) and a tool or bit ( 24 ) mounted therein, as is well known in the art. Also, the motor of the hammer selectively drives an air cushion hammering mechanism for repeatedly impacting the tool or bit ( 24 ), as is well known in the art. A mode change arrangement, actuated by a mode change knob ( 50 ), is provided for enabling the selective engagement of rotary drive to the spindle and/or selective actuation of the air cushion hammering mechanism so that the hammer can be operated in a drilling only mode, a hammering only mode and/or a combination rotary hammering mode, as is well known in the art.
The rotary hammer is powered by a battery pack ( 4 ), of the type shown in the Figures. The battery pack comprises a housing ( 6 ) in which a number of rechargeable electrical cells ( 7 ) are housed, as is well known in the art. The housing ( 6 ) has an upper sub-housing ( 10 ) which covers a portion of the upper surface of the housing ( 6 ). The sub-housing houses an electrical connection arrangement (Z) (See FIG. 7 ) to the cells ( 7 ) of the battery pack which is accessible by via a plurality of passageways into the sub-housing ( 10 ), which passageways are separated by guide ribs ( 8 ). A recess ( 12 ) for receiving a fixing latch is formed in the upper surface of the sub-housing ( 10 ) and a pair of outwardly facing rails ( 14 ) are formed to either side of the sub-housing so as to extend in the longitudinal direction of the battery pack, designated by arrow (A). A recess is formed underneath each rail, which recess is terminated by a rib ( 16 ) at a first end of the recess.
The battery pack ( 4 ) can be releasably mounted on the rotary hammer, as shown in FIG. 1 . The hammer has a lower housing portion ( 22 ) on the underside of which are formed a pair of inwardly facing rails ( 28 ) (see FIG. 2 ) which cooperate with the outwardly facing pair of rails ( 14 ) on the battery pack, so that a sliding rail and groove connection can be formed between the battery pack ( 4 ) and the lower housing portion ( 22 ). The forward ends of the pair of rails ( 28 ) are initially engaged with the open ends of the recesses under the rails ( 14 ) and then the battery pack is slid rearwardly with respect to the lower housing portion ( 22 ) until the open ends of the rails ( 14 ) abut a stop arrangement on the underside of the lower housing portion ( 22 ). As the rails ( 14 ) come into abutment with the stop arrangement a spring biased latch (not shown) extending downwardly from the underside of the lower housing portion ( 22 ) engages in the recess ( 12 ) in the sub-housing ( 10 ) of the battery pack ( 4 ) to thereby secure the battery pack to the lower housing portion. Also, as the battery pack ( 4 ) is moved rearwardly along the rails ( 28 ) electrical connectors (Y) (See FIG. 7 ) on the underside of the lower housing portion ( 22 ) move into the passageways between the ribs ( 8 ) of the sub-housing ( 10 ) of the battery pack and into electrical connection with the electrical connection (Z) to the cells ( 7 ). Thereby, the motor of the hammer is electrically connected to and powered by the cells of the battery pack ( 4 ).
In order to remove the battery pack ( 4 ) from the lower housing portion ( 22 ), a button ( 30 ) on the side of the lower housing portion is depressed so as to retract the latch from the recess ( 12 ) in the sub-housing ( 10 ) of the battery pack ( 4 ). Thereafter, the battery pack can be moved slideably forward along the rails ( 28 ) of the lower housing portion ( 22 ) and removed completely from the lower housing portion ( 22 ), for example for charging.
FIGS. 4 to 6 show a dust collection unit ( 40 ) for the hammer. The dust collection unit comprises a dust collection shroud ( 32 ) which, when the unit ( 40 ) is mounted on the hammer (as shown in FIG. 6 ), surrounds the forward end of a tool or bit ( 24 ) mounted in the tool holder ( 26 ) of the hammer. The shroud ( 32 ) forms a chamber around the forward end of the tool or bit ( 24 ), the rearward wall of which is formed by a flexible brush ( 34 ) which fits around the tool or bit ( 24 ). The shroud ( 32 ) is mounted on a support arm ( 36 ) which is telescopically mounted within a receiving portion ( 38 ) of a main housing of the dust collection unit ( 40 ). The support arm ( 36 ) can be pushed into the receiving portion ( 38 ) against a biasing force from a spring arrangement contained in the receiving portion ( 38 ). The maximum extent to which the support arm ( 36 ) extends forwardly of the receiving portion ( 38 ) and the extent to which the support arm can be retracted into the receiving portion can be set by the adjustment of a pair of stops ( 42 , 44 ). A channel extends along the support arm ( 36 ) with a first end of the channel communicating with the chamber of the shroud ( 32 ) and the second end of the channel communicating with an entrance to a filter chamber of the unit ( 40 ).
The unit ( 40 ) comprises a filter chamber, formed partially by a releasable cover ( 46 ). A filter arrangement is housed within the filter chamber. The filter chamber has an inlet which communicates with the channel in the support arm ( 36 ) and an outlet which communicates with an inlet to a fan. The fan has an outlet ( 48 ). The fan is powered by a motor ( 49 ) housed in the rearward housing portion ( 50 ) of the dust collection unit ( 40 ).
The rearward housing portion ( 50 ) of the dust collection unit ( 40 ) has an upper sub-housing ( 52 ) which covers a portion of the upper surface of the housing portion ( 50 ). The sub-housing houses a first electrical connection arrangement (X) which is connected to the fan motor ( 49 ) of the unit ( 40 ) and which is connected to a second electrical connection arrangement (W) for connection to a battery pack ( 4 ) (as described below) (See FIG. 7 ). The first electrical connection arrangement (X) of the unit ( 40 ) is accessible via a plurality of passageways into the sub-housing ( 52 ), which passageways are separated by guide ribs ( 54 ). A pair of outwardly facing rails ( 56 ) are formed to either side of the sub-housing so as to extend in the longitudinal direction of the unit ( 40 ), designated by arrow (B). A recess is formed underneath each rail, which recess is terminated by a rib ( 58 ) at a first forward end of the recess. The unit ( 40 ) is formed with an upwardly extending projection ( 60 ) which is engageable with a correspondingly shaped recess on the underside of the housing of the hammer. The unit ( 40 ) is also provided with a rearwardly extending retractable latch ( 62 ) which is engageable with a correspondingly shaped recess of the underside of the housing of the hammer. The latch ( 62 ) can be retracted against a biasing spring arrangement by pressing a button located on the opposite side of the hammer housing to that shown in the Figures.
The dust collection unit ( 40 ) can be releasably mounted on the rotary hammer, as shown in FIG. 6 . The pair of inwardly facing rails ( 28 ) (see FIG. 2 ) of the hammer cooperate with the outwardly facing pair of rails ( 56 ) on the unit ( 40 ), so that a sliding rail and groove connection can be formed between the unit ( 40 ) and the lower housing portion ( 22 ). The forward ends of the pair of rails ( 28 ) are initially engaged with the open ends of the recesses under the rails ( 56 ) and then the dust collection unit ( 40 ) is slid rearwardly with respect to the lower housing portion ( 22 ) until the open ends of the rails ( 56 ) abut a stop arrangement on the underside of the lower housing portion ( 22 ). As the rails ( 56 ) come into abutment with the stop arrangement, the projection ( 60 ) can be moved upwardly into engagement with the corresponding recess on the hammer housing and the latch ( 62 ) engages in the corresponding the recess in the housing of the hammer to thereby secure the unit ( 40 ) to the hammer housing. Also, as the unit ( 40 ) is moved rearwardly along the rails ( 28 ) electrical connectors (Y) on the underside of the lower housing portion ( 22 ) move into the passageways between the ribs ( 54 ) of the sub-housing ( 52 ) of the unit ( 40 ) and into electrical connection with the first electrical connection arrangement (X) and thus into connection with the fan motor ( 49 ) and with the second electrical connection arrangement (W) for connection to a battery pack ( 4 ) (See FIG. 7 ).
In order to remove the unit ( 40 ) from the housing of the hammer, the button on the dust collection unit ( 40 ) is depressed so as to retract the latch ( 62 ) from the corresponding recess ( 12 ) in the hammer housing. Thereafter, the unit ( 40 ) can be tilted downwardly to release the projection ( 60 ) from its corresponding recess in the hammer housing and then the unit ( 40 ) can be moved slideably forward along the rails ( 28 ) of the lower housing portion ( 22 ) and removed completely from the lower housing portion ( 22 ).
The fan motor ( 49 ) of unit ( 40 ) and the motor ( 3 ) of the hammer can both be powered by a battery pack ( 4 ), of the type described above. The battery pack ( 4 ) can be fitted to the unit ( 40 ) so as to power the fan motor of the unit and power the motor of the hammer via the unit.
The dust collection unit ( 40 ) has a rearward housing portion ( 50 ) on the underside of which are formed a pair of inwardly facing rails ( 64 ) (see FIG. 4 ) which cooperate with the outwardly facing pair of rails ( 14 ) on the battery pack, so that a sliding rail and groove connection can be formed between the battery pack ( 4 ) and the rearward housing portion ( 50 ). The rearward ends of the pair of rails ( 64 ) are initially engaged with the open ends of the recesses under the rails ( 14 ) and then the battery pack is slid forwardly with respect to the rearward housing portion ( 50 ) until the open ends of the rails ( 14 ) abut a stop arrangement on the underside of the rearward housing portion ( 50 ). As the rails ( 14 ) come into abutment with the stop arrangement a spring biased latch (not shown) extending downwardly from the underside of the rearward housing portion ( 50 ) engages in the recess ( 12 ) in the sub-housing ( 10 ) of the battery pack ( 4 ) to thereby secure the battery pack to the rearward housing portion of the dust collection unit ( 40 ). Also, as the battery pack ( 4 ) is moved forwardly along the rails ( 28 ) the second electrical connection arrangement (W) on the underside of the rearward housing portion ( 50 ) of the dust collection unit ( 40 ) moves into the passageways between the ribs ( 8 ) of the sub-housing ( 10 ) of the battery pack and into electrical connection with the electrical connection (Z) to the cells. Thereby, the fan motor ( 49 ) of the dust collection unit ( 40 ) is electrically connected to and powered by the cells ( 7 ) of the battery pack ( 4 ). There is also an electrical connection between the second electrical connection arrangement (W) on the underside of the rearward housing portion ( 50 ) and the first electrical connection arrangement (X) of the sub-housing ( 52 ) of the housing portion ( 50 ), via which the motor ( 3 ) of the hammer is powered, when the dust collection unit is fitted on the hammer, as shown in FIG. 6 . The circuit diagram showing the wiring between the battery pack ( 4 ), the dust extraction unit ( 40 ) and the rotary hammer is shown in FIG. 7 .
In order to remove the battery pack ( 4 ) from the rearward housing portion ( 50 ) of the dust extraction unit ( 40 ), a button ( 66 ) on the side of the rearward housing portion is depressed so as to retract the latch from the recess ( 12 ) in the sub-housing ( 10 ) of the battery pack ( 4 ). Thereafter, the battery pack can be moved slideably rearward along the rails ( 64 ) of the rearward housing portion ( 50 ) and removed completely from the lower housing portion ( 22 ), for example for charging.
Thus, in order to use the hammer without the dust collection unit ( 40 ), the battery pack ( 4 ) is fitted to the hammer as shown in FIG. 1 . The battery pack ( 4 ) can be removed from the hammer, as shown in FIG. 2 , for re-charging of the battery pack.
In order to use the hammer with the dust collection unit ( 40 ) the battery pack is removed forwardly from the hammer, and the dust extraction unit is fitted to the hammer, as described above. The battery pack ( 4 ) is turned through 180° and mounted on the dust extraction unit ( 40 ) from the rearward direction. The resulting configuration is shown in FIG. 6 . Then the shroud is adjusted, according to the length of the tool or bit ( 24 ), by adjusting the stops ( 42 , 44 ) so that the chamber of the shroud ( 32 ) surrounds the forwardmost portion of the tool or bit so that when the tool or bit is pressed against a surface to be worked on, the forwardmost rim of the shroud ( 32 ) abuts the surface. Then when the motor ( 3 ) of the hammer is actuated, by depressing the trigger ( 20 ) of the hammer, the cells ( 7 ) of the battery pack ( 4 ) power the motor ( 3 ) of the hammer via the connections (ZW) and (XY) through the dust collection unit ( 40 ) and power the fan motor ( 49 ) of the dust collection unit ( 40 ). The tool or bit ( 24 ) is pressed against the surface and dust is generated.
The motor fan generates an airflow which is pulled into the shroud, for example via one or more recesses in the forward face of the rim of the shroud ( 32 ), and from the shroud through the channel in the support arm ( 36 ) and into the inlet to the filter housing. The generated dust is entrained in this airflow and thus transported into the filter housing. The dust is captured in the filter housing by a filter arrangement and the air passes through the filter and into the inlet of the fan. The air passes through the fan and is discharged out of the outlet ( 48 ) to the fan. Periodically, the filter housing cover ( 46 ) can be removed and the filter housing emptied of collected dust. As the tool or bit ( 24 ) moves into the surface being worked, the support arm ( 36 ) retracts against the biasing force of the spring arrangement and maintains the forwardmost rim of the shroud against the surface being worked. When the trigger ( 20 ) of the hammer is released, the power to the hammer motor and the fan motor is disconnected. | An accessory system, such as a dust collection system ( 40 ) of a hand held power tool, such as a drilling and/or hammering tool comprising, the tool, an accessory unit ( 40 ) comprising a separate motor for powering the unit and releasably mountable on the tool, and a battery pack ( 4 ). When the accessory unit is not required, the battery pack can be mounted directly on the tool for powering to tool and when the accessory unit is required the battery pack can be mounted on the accessory unit for powering the accessory unit and, when the accessory unit is mounted on the tool, for powering the tool via the accessory unit. | 1 |
[0001] The applicants claim the benefits under Title 35, United States Code, Section 119(e) of prior U.S. Provisional Application No. 61/876,404 which was filed on Sep. 11, 2013. Assignees S.M.E. Products LP and Ortloff Engineers, Ltd. were parties to a joint research agreement that was in effect before the invention of this application was made.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a process and apparatus for improving the separation of a gas containing hydrocarbons.
[0003] Ethylene, ethane, propylene, propane, and/or heavier hydrocarbons can be recovered from a variety of gases, such as natural gas, refinery gas, and synthetic gas streams obtained from other hydrocarbon materials such as coal, crude oil, naphtha, oil shale, tar sands, and lignite. Natural gas usually has a major proportion of methane and ethane, i.e., methane and ethane together comprise at least 50 mole percent of the gas. The gas also contains relatively lesser amounts of heavier hydrocarbons such as propane, butanes, pentanes, and the like, as well as hydrogen, nitrogen, carbon dioxide, and/or other gases.
[0004] The present invention is generally concerned with improving the recovery of ethylene, ethane, propylene, propane, and heavier hydrocarbons from such gas streams. A typical analysis of a gas stream to be processed in accordance with this invention would be, in approximate mole percent, 90.3% methane, 4.0% ethane and other C 2 components, 1.7% propane and other C 3 components, 0.3% iso-butane, 0.5% normal butane, and 0.8% pentanes plus, with the balance made up of nitrogen and carbon dioxide. Sulfur containing gases are also sometimes present.
[0005] The historically cyclic fluctuations in the prices of both natural gas and its natural gas liquid (NGL) constituents have at times reduced the incremental value of ethane, ethylene, propane, propylene, and heavier components as liquid products. This has resulted in a demand for processes that can provide more efficient recoveries of these products, for processes that can provide efficient recoveries with lower capital investment, and for processes that can be easily adapted or adjusted to vary the recovery of a specific component over a broad range. Available processes for separating these materials include those based upon cooling and refrigeration of gas, oil absorption, and refrigerated oil absorption. Additionally, cryogenic processes have become popular because of the availability of economical equipment that produces power while simultaneously expanding and extracting heat from the gas being processed. Depending upon the pressure of the gas source, the richness (ethane, ethylene, and heavier hydrocarbons content) of the gas, and the desired end products, each of these processes or a combination thereof may be employed.
[0006] The cryogenic expansion process is now generally preferred for natural gas liquids recovery because it provides maximum simplicity with ease of startup, operating flexibility, good efficiency, safety, and good reliability. U.S. Pat. Nos. 3,292,380; 4,061,481; 4,140,504; 4,157,904; 4,171,964; 4,185,978; 4,251,249; 4,278,457; 4,519,824; 4,617,039; 4,687,499; 4,689,063; 4,690,702; 4,854,955; 4,869,740; 4,889,545; 5,275,005; 5,555,748; 5,566,554; 5,568,737; 5,771,712; 5,799,507; 5,881,569; 5,890,378; 5,983,664; 6,182,469; 6,578,379; 6,712,880; 6,915,662; 7,191,617; 7,219,513; 8,590,340; reissue U.S. Pat. No. 33,408; and co-pending application Ser. Nos. 11/430,412; 11/839,693; 12/206,230; 12/689,616; 12/717,394; 12/750,862; 12/772,472; 12/781,259; 12/868,993; 12/869,007; 12/869,139; 12/979,563; 13/048,315; 13/051,682; 13/052,348; 13/052,575; and 13/053,792 describe relevant processes (although the description of the present invention in some cases is based on different processing conditions than those described in the cited U.S. Patents and co-pending applications).
[0007] In a typical cryogenic expansion recovery process, a feed gas stream under pressure is cooled by heat exchange with other streams of the process and/or external sources of refrigeration such as a propane compression-refrigeration system. As the gas is cooled, liquids may be condensed and collected in one or more separators as high-pressure liquids containing some of the desired C 2 + components. Depending on the richness of the gas and the amount of liquids formed, the high-pressure liquids may be expanded to a lower pressure and fractionated. The vaporization occurring during expansion of the liquids results in further cooling of the stream. Under some conditions, pre-cooling the high pressure liquids prior to the expansion may be desirable in order to further lower the temperature resulting from the expansion. The expanded stream, comprising a mixture of liquid and vapor, is fractionated in a distillation (demethanizer or deethanizer) column. In the column, the expansion cooled stream(s) is (are) distilled to separate residual methane, nitrogen, and other volatile gases as overhead vapor from the desired C 2 components, C 3 components, and heavier hydrocarbon components as bottom liquid product, or to separate residual methane, C 2 components, nitrogen, and other volatile gases as overhead vapor from the desired C 3 components and heavier hydrocarbon components as bottom liquid product.
[0008] If the feed gas is not totally condensed (typically it is not), the vapor remaining from the partial condensation can be split into two streams. One portion of the vapor is passed through a work expansion machine or engine, or an expansion valve, to a lower pressure at which additional liquids are condensed as a result of further cooling of the stream. The pressure after expansion is essentially the same as the pressure at which the distillation column is operated. The combined vapor-liquid phases resulting from the expansion are supplied as feed to the column.
[0009] The remaining portion of the vapor is cooled to substantial condensation by heat exchange with other process streams, e.g., the cold fractionation tower overhead. Some or all of the high-pressure liquid may be combined with this vapor portion prior to cooling. The resulting cooled stream is then expanded through an appropriate expansion device, such as an expansion valve, to the pressure at which the demethanizer is operated. During expansion, a portion of the liquid will vaporize, resulting in cooling of the total stream. The flash expanded stream is then supplied as top feed to the demethanizer. Typically, the vapor portion of the flash expanded stream and the demethanizer overhead vapor combine in an upper separator section in the fractionation tower as residual methane product gas. Alternatively, the cooled and expanded stream may be supplied to a separator to provide vapor and liquid streams. The vapor is combined with the tower overhead and the liquid is supplied to the column as a top column feed.
[0010] In the ideal operation of such a separation process, the residue gas leaving the process will contain substantially all of the methane in the feed gas with essentially none of the heavier hydrocarbon components, and the bottoms fraction leaving the demethanizer will contain substantially all of the heavier hydrocarbon components with essentially no methane or more volatile components. In practice, however, this ideal situation is not obtained because the conventional demethanizer is operated largely as a stripping column. The methane product of the process, therefore, typically comprises vapors leaving the top fractionation stage of the column, together with vapors not subjected to any rectification step. Considerable losses of C 2 , C 3 , and C 4 + components occur because the top liquid feed contains substantial quantities of these components and heavier hydrocarbon components, resulting in corresponding equilibrium quantities of C 2 components, C 3 components, C 4 components, and heavier hydrocarbon components in the vapors leaving the top fractionation stage of the demethanizer. The loss of these desirable components could be significantly reduced if the rising vapors could be brought into contact with a significant quantity of liquid (reflux) capable of absorbing the C 2 components, C 3 components, C 4 components, and heavier hydrocarbon components from the vapors.
[0011] In recent years, the preferred processes for hydrocarbon separation use an upper absorber section to provide additional rectification of the rising vapors. For many of these processes, the source of the reflux stream for the upper rectification section is a recycled stream of residue gas supplied under pressure. The recycled residue gas stream is usually cooled to substantial condensation by heat exchange with other process streams, e.g., the cold fractionation tower overhead. The resulting substantially condensed stream is then expanded through an appropriate expansion device, such as an expansion valve, to the pressure at which the demethanizer is operated. During expansion, a portion of the liquid will usually vaporize, resulting in cooling of the total stream. The flash expanded stream is then supplied as top feed to the demethanizer. Typical process schemes of this type are disclosed in U.S. Pat. Nos. 4,889,545; 5,568,737; and 5,881,569, in co-pending application Ser. Nos. 12/717,394 and 13/052,348, and in Mowrey, E. Ross, “Efficient, High Recovery of Liquids from Natural Gas Utilizing a High Pressure Absorber”, Proceedings of the Eighty-First Annual Convention of the Gas Processors Association, Dallas, Tex., Mar. 11-13, 2002. Unfortunately, in addition to the additional rectification section in the demethanizer, these processes also require the use of a compressor to provide the motive force for recycling the reflux stream to the demethanizer, adding to both the capital cost and the operating cost of facilities using these processes.
[0012] Another method of generating a reflux stream for the upper rectification section is to use the flash expanded substantially condensed stream to cool and partially condense the column overhead vapor, with the heated flash expanded stream then directed to a mid-column feed point on the demethanizer. The liquid condensed from the column overhead vapor is separated and supplied as top feed to the demethanizer, while the uncondensed vapor is discharged as the residual methane product gas. The heated flash expanded stream is only partially vaporized, and so contains a substantial quantity of liquid that serves as supplemental reflux for the demethanizer, so that the top reflux feed can then rectify the vapors leaving the lower section of the column. U.S. Pat. No. 4,854,955 is an example of this type of process. Unfortunately, this type of process requires the additional rectification section plus the reflux condenser, drum, and pumps to generate the reflux stream for the column, adding to the capital cost of facilities using this process.
[0013] However, there are many gas processing plants that have been built in the U.S. and other countries according to U.S. Pat. Nos. 4,157,904 and 4,278,457 (as well as other processes) that have no upper absorber section to provide additional rectification of the rising vapors and cannot be easily modified to add this feature. Also, these plants do not usually have surplus compression capacity to allow recycling a reflux stream, nor do their demethanizer or deethanizer columns have surplus fractionation capacity to accommodate the increase in feed rate that results when a new reflux stream is added. As a result, these plants are not as efficient when operated to recover C 2 components and heavier components from the gas (commonly referred to as “ethane recovery”), and are particularly inefficient when operated to recover only the C 3 components and heavier components from the gas (commonly referred to as “ethane rejection”).
[0014] The present invention is a novel means of providing additional rectification (similar to what is used in U.S. Pat. No. 4,854,955 and co-pending application Ser. Nos. 12/772,472 and 13/053,792) that can be easily added to existing gas processing plants to increase the recovery of the desired C 3 components without requiring additional compression or fractionation capacity. The incremental value of this increased recovery is often substantial. For the Examples given later, the incremental income from the additional recovery capability over that of the prior art is in the range of US$575,000 to US$1,120,000 [ 430,000 to 835,000] per year using an average incremental value US$0.74-1.08 per gallon [ 145-214 per m 3 ] for hydrocarbon liquids compared to the corresponding hydrocarbon gases.
[0015] The present invention also combines what heretofore have been individual equipment items into a common housing, thereby reducing both the plot space requirements and the capital cost of the addition. Surprisingly, applicants have found that the more compact arrangement also significantly increases the product recovery at a given power consumption, thereby increasing the process efficiency and reducing the operating cost of the facility. In addition, the more compact arrangement also eliminates much of the piping used to interconnect the individual equipment items in traditional plant designs, further reducing capital cost and also eliminating the associated flanged piping connections. Since piping flanges are a potential leak source for hydrocarbons (which are volatile organic compounds, VOCs, that contribute to greenhouse gases and may also be precursors to atmospheric ozone formation), eliminating these flanges reduces the potential for atmospheric emissions that may damage the environment.
[0016] In accordance with the present invention, it has been found that C 2 recoveries in excess of 89% can be obtained. Similarly, in those instances where recovery of C 2 components is not desired, C 3 recoveries in excess of 99% can be maintained. The present invention, although applicable at lower pressures and warmer temperatures, is particularly advantageous when processing feed gases in the range of 400 to 1500 psia [2,758 to 10,342 kPa(a)] or higher under conditions requiring NGL recovery column overhead temperatures of −50° F. [−46° C.] or colder.
[0017] For a better understanding of the present invention, reference is made to the following examples and drawings. Referring to the drawings:
[0018] FIGS. 1, 2, and 3 are flow diagrams of prior art natural gas processing plants in accordance with U.S. Pat. No. 4,157,904 or 4,278,457;
[0019] FIGS. 4, 5, and 6 are flow diagrams of natural gas processing plants adapted to use the present invention; and
[0020] FIGS. 7 and 8 are flow diagrams illustrating alternative means of application of the present invention to a natural gas processing plant.
[0021] In the following explanation of the above figures, tables are provided summarizing flow rates calculated for representative process conditions. In the tables appearing herein, the values for flow rates (in moles per hour) have been rounded to the nearest whole number for convenience. The total stream rates shown in the tables include all non-hydrocarbon components and hence are generally larger than the sum of the stream flow rates for the hydrocarbon components. Temperatures indicated are approximate values rounded to the nearest degree. It should also be noted that the process design calculations performed for the purpose of comparing the processes depicted in the figures are based on the assumption of no heat leak from (or to) the surroundings to (or from) the process. The quality of commercially available insulating materials makes this a very reasonable assumption and one that is typically made by those skilled in the art.
[0022] For convenience, process parameters are reported in both the traditional British units and in the units of the Système International d'Unités (SI). The molar flow rates given in the tables may be interpreted as either pound moles per hour or kilogram moles per hour. The energy consumptions reported as horsepower (HP) and/or thousand British Thermal Units per hour (MBTU/Hr) correspond to the stated molar flow rates in pound moles per hour. The energy consumptions reported as kilowatts (kW) correspond to the stated molar flow rates in kilogram moles per hour.
DESCRIPTION OF THE PRIOR ART
[0023] FIG. 1 is a process flow diagram showing the design of a processing plant to recover C 2 + components from natural gas using prior art according to U.S. Pat. No. 4,157,904 or 4,278,457. In this simulation of the process, inlet gas enters the plant at 100° F. [38° C.] and 915 psia [6,307 kPa(a)] as stream 31 . If the inlet gas contains a concentration of sulfur compounds which would prevent the product streams from meeting specifications, the sulfur compounds are removed by appropriate pretreatment of the feed gas (not illustrated). In addition, the feed stream is usually dehydrated to prevent hydrate (ice) formation under cryogenic conditions. Solid desiccant has typically been used for this purpose.
[0024] The feed stream 31 is cooled in heat exchanger 10 by heat exchange with cool residue gas (stream 39 a ), demethanizer reboiler liquids at 44° F. [7° C.] (stream 41 ), and demethanizer side reboiler liquids at −49° F. [−45° C.] (stream 40 ). (In some cases, the use of one or more supplemental external refrigeration streams may be advantageous as shown by the dashed line.) Stream 31 a then enters separator 11 at −24° F. [−31° C.] and 900 psia [6,203 kPa(a)] where the vapor (stream 32 ) is separated from the condensed liquid (stream 33 ).
[0025] The vapor (stream 32 ) from separator 11 is divided into two streams, 34 and 37 . The liquid (stream 33 ) from separator 11 is optionally divided into two streams, 35 and 38 . (Stream 35 may contain from 0% to 100% of the separator liquid in stream 33 . If stream 35 contains any portion of the separator liquid, then the process of FIG. 1 is according to U.S. Pat. No. 4,157,904. Otherwise, the process of FIG. 1 is according to U.S. Pat. No. 4,278,457.) For the process illustrated in FIG. 1 , stream 35 contains 100% of the total separator liquid. Stream 34 , containing about 31% of the total separator vapor, is combined with stream 35 and the combined stream 36 passes through heat exchanger 12 in heat exchange relation with the cold residue gas (stream 39 ) where it is cooled to substantial condensation. The resulting substantially condensed stream 36 a at −134° F. [−92° C.] is then flash expanded through expansion valve 13 to the operating pressure (approximately 395 psia [2,721 kPa(a)]) of fractionation tower 17 . During expansion a portion of the stream is vaporized, resulting in cooling of the total stream. In the process illustrated in FIG. 1 , the expanded stream 36 b leaving expansion valve 13 reaches a temperature of −140° F. [−96° C.] and is supplied to separator section 17 a in the upper region of fractionation tower 17 . The liquids separated therein become the top feed to demethanizing section 17 b.
[0026] The remaining 69% of the vapor from separator 11 (stream 37 ) enters a work expansion machine 14 in which mechanical energy is extracted from this portion of the high pressure feed. The machine 14 expands the vapor substantially isentropically to the tower operating pressure, with the work expansion cooling the expanded stream 37 a to a temperature of approximately −95° F. [−70° C.]. The typical commercially available expanders are capable of recovering on the order of 80-85% of the work theoretically available in an ideal isentropic expansion. The work recovered is often used to drive a centrifugal compressor (such as item 15 ) that can be used to re-compress the residue gas (stream 39 b ), for example. The partially condensed expanded stream 37 a is thereafter supplied as feed to fractionation tower 17 at an upper mid-column feed point. The remaining separator liquid in stream 38 (if any) is expanded to the operating pressure of fractionation tower 17 by expansion valve 16 , cooling stream 38 a before it is supplied to fractionation tower 17 at a lower mid-column feed point.
[0027] The demethanizer in tower 17 is a conventional distillation column containing a plurality of vertically spaced trays, one or more packed beds, or some combination of trays and packing. As is often the case in natural gas processing plants, the fractionation tower may consist of two sections. The upper section 17 a is a separator wherein the partially vaporized top feed is divided into its respective vapor and liquid portions, and wherein the vapor rising from the lower distillation or demethanizing section 17 b is combined with the vapor portion of the top feed to form the cold demethanizer overhead vapor (stream 39 ) which exits the top of the tower. The lower, demethanizing section 17 b contains the trays and/or packing and provides the necessary contact between the liquids falling downward and the vapors rising upward. The demethanizing section 17 b also includes reboilers (such as the reboiler and the side reboiler described previously and supplemental reboiler 18 ) which heat and vaporize a portion of the liquids flowing down the column to provide the stripping vapors which flow up the column to strip the liquid product, stream 42 , of methane and lighter components.
[0028] The liquid product stream 42 exits the bottom of the tower at 67° F. [19° C.], based on a typical specification of a methane to ethane ratio of 0.010:1 on a molar basis in the bottom product. The residue gas (demethanizer overhead vapor stream 39 ) passes countercurrently to the incoming feed gas in heat exchanger 12 where it is heated from −139° F. [−95° C.] to −37° F. [−38° C.] (stream 39 a ) and in heat exchanger 10 where it is heated to 91° F. [33° C.] (stream 39 b ). The residue gas is then re-compressed in two stages. The first stage is compressor 15 driven by expansion machine 14 . The second stage is compressor 19 driven by a supplemental power source which compresses the residue gas (stream 39 d ) to sales line pressure. After cooling to 110° F. [43° C.] in discharge cooler 20 , the residue gas product (stream 39 e ) flows to the sales gas pipeline at 915 psia [6,307 kPa(a)], sufficient to meet line requirements (usually on the order of the inlet pressure).
[0029] A summary of stream flow rates and energy consumption for the process illustrated in FIG. 1 is set forth in the following table:
[0000]
TABLE I
(FIG. 1)
Stream Flow Summary - Lb. Moles/Hr [kg moles/Hr]
Stream
Methane
Ethane
Propane
Butanes+
Total
31
12,398
546
233
229
13,726
32
12,202
504
183
82
13,281
33
196
42
50
147
445
34
3,909
161
59
26
4,255
36
4,105
203
109
173
4,700
37
8,293
343
124
56
9,026
39
12,393
55
5
1
12,636
42
5
491
228
228
1,090
Recoveries*
Ethane
89.85%
Propane
98.05%
Butanes+
99.71%
Power
Residue Gas Compression
5,569 HP
[9,155 kW]
*(Based on un-rounded flow rates)
[0030] FIG. 2 is a process flow diagram showing one manner in which the design of the processing plant in FIG. 1 can be adjusted to operate at a lower C 2 component recovery level. This is a common requirement when the relative values of natural gas and liquid hydrocarbons are variable, causing recovery of the C 2 components to be unprofitable at times. The process of FIG. 2 has been applied to the same feed gas composition and conditions as described previously for FIG. 1 . However, in the simulation of the process of FIG. 2 , the process operating conditions have been adjusted to reject nearly all of C 2 components to the residue gas rather than recovering them in the bottom liquid product from the fractionation tower.
[0031] In this simulation of the process, inlet gas enters the plant at 100° F. [38° C.] and 915 psia [6,307 kPa(a)] as stream 31 and is cooled in heat exchanger 10 by heat exchange with cool residue gas stream 39 a . (One consequence of operating the FIG. 2 process to reject nearly all of the C 2 components to the residue gas is that the temperatures of the liquids flowing down fractionation tower 17 are much warmer, to the point that side reboiler stream 40 and reboiler stream 41 can no longer be used to cool the inlet gas and all of the column reboil heat must be supplied by supplemental reboiler 18 .) Cooled stream 31 a enters separator 11 at 2° F. [−17° C.] and 900 psia [6,203 kPa(a)] where the vapor (stream 32 ) is separated from the condensed liquid (stream 33 ).
[0032] The vapor (stream 32 ) from separator 11 is divided into two streams, 34 and 37 , and the liquid (stream 33 ) is optionally divided into two streams, 35 and 38 . For the process illustrated in FIG. 2 , stream 35 contains 100% of the total separator liquid. Stream 34 , containing about 24% of the total separator vapor, is combined with stream 35 and the combined stream 36 passes through heat exchanger 12 in heat exchange relation with the cold residue gas (stream 39 ) where it is cooled to substantial condensation. The resulting substantially condensed stream 36 a at −102° F. [−75° C.] is then flash expanded through expansion valve 13 to the operating pressure (approximately 398 psia [2,747 kPa(a)]) of fractionation tower 17 . During expansion a portion of the stream is vaporized, resulting in cooling of the total stream. In the process illustrated in FIG. 2 , the expanded stream 36 b leaving expansion valve 13 reaches a temperature of −137° F. [−94° C.] and is supplied to fractionation tower 17 at the top feed point.
[0033] The remaining 76% of the vapor from separator 11 (stream 37 ) enters a work expansion machine 14 in which mechanical energy is extracted from this portion of the high pressure feed. The machine 14 expands the vapor substantially isentropically to the tower operating pressure, with the work expansion cooling the expanded stream 37 a to a temperature of approximately −71° F. [−57° C.] before it is supplied as feed to fractionation tower 17 at an upper mid-column feed point. The remaining separator liquid in stream 38 (if any) is expanded to the operating pressure of fractionation tower 17 by expansion valve 16 , cooling stream 38 a before it is supplied to fractionation tower 17 at a lower mid-column feed point.
[0034] Note that when fractionation tower 17 is operated to reject the C 2 components to the residue gas product as shown in FIG. 2 , the column is typically referred to as a deethanizer and its lower section 17 b is called a deethanizing section. The liquid product stream 42 exits the bottom of deethanizer 17 at 230° F. [110° C.], based on a typical specification of an ethane to propane ratio of 0.020:1 on a molar basis in the bottom product. The residue gas (deethanizer overhead vapor stream 39 ) passes countercurrently to the incoming feed gas in heat exchanger 12 where it is heated from −108° F. [−78° C.] to −36° F. [−38° C.] (stream 39 a ) and in heat exchanger 10 where it is heated to 99° F. [37° C.] (stream 39 b ) as it provides cooling as previously described. The residue gas is then re-compressed in two stages, compressor 15 driven by expansion machine 14 and compressor 19 driven by a supplemental power source. After stream 39 d is cooled to 110° F. [43° C.] in discharge cooler 20 , the residue gas product (stream 39 e ) flows to the sales gas pipeline at 915 psia [6,307 kPa(a)].
[0035] A summary of stream flow rates and energy consumption for the process illustrated in FIG. 2 is set forth in the following table:
[0000]
TABLE II
(FIG. 2)
Stream Flow Summary - Lb. Moles/Hr [kg moles/Hr]
Stream
Methane
Ethane
Propane
Butanes+
Total
31
12,398
546
233
229
13,726
32
12,304
526
208
117
13,470
33
94
20
25
112
256
34
3,040
130
51
29
3,328
36
3,134
150
76
141
3,584
37
9,264
396
157
88
10,142
39
12,398
542
15
2
13,276
42
0
4
218
227
450
Recoveries*
Propane
93.60%
Butanes+
99.12%
Power
Residue Gas Compression
5,565 HP
[9,149 kW]
*(Based on un-rounded flow rates)
[0036] Product economics sometimes favor rejecting only a portion of the C 2 components to the residue gas product. FIG. 3 is a process flow diagram showing one manner in which the design of the processing plant in FIG. 1 can be adjusted to operate at an intermediate C 2 component recovery level. The process of FIG. 3 has been applied to the same feed gas composition and conditions as described previously for FIGS. 1 and 2 . However, in the simulation of the process of FIG. 3 , the process operating conditions have been adjusted to recover about half as much of the C 2 components in the bottom liquid product from the fractionation tower compared to the quantity of C 2 components recovered by the FIG. 1 process.
[0037] In this simulation of the process, inlet gas enters the plant at 100° F. [38° C.] and 915 psia [6,307 kPa(a)] as stream 31 and is cooled in heat exchanger 10 by heat exchange with cool residue gas stream 39 a and demethanizer side reboiler liquids at 63° F. [17° C.] (stream 40 ). (At the C 2 component recovery level of the FIG. 3 process, the side reboiler stream 40 is still cool enough to be used to cool the inlet gas, reducing the amount of column reboil heat that must be supplied by supplemental reboiler 18 .) Cooled stream 31 a enters separator 11 at 8° F. [−14° C.] and 900 psia [6,203 kPa(a)] where the vapor (stream 32 ) is separated from the condensed liquid (stream 33 ).
[0038] The vapor (stream 32 ) from separator 11 is divided into two streams, 34 and 37 , and the liquid (stream 33 ) is optionally divided into two streams, 35 and 38 . For the process illustrated in FIG. 3 , stream 35 contains 100% of the total separator liquid. Stream 34 , containing about 27% of the total separator vapor, is combined with stream 35 and the combined stream 36 passes through heat exchanger 12 in heat exchange relation with the cold residue gas (stream 39 ) where it is cooled to substantial condensation. The resulting substantially condensed stream 36 a at −120° F. [−85° C.] is then flash expanded through expansion valve 13 to the operating pressure (approximately 384 psia [2,644 kPa(a)]) of fractionation tower 17 . During expansion a portion of the stream is vaporized, resulting in cooling of the total stream. In the process illustrated in FIG. 3 , the expanded stream 36 b leaving expansion valve 13 reaches a temperature of −141° F. [−96° C.] and is supplied to fractionation tower 17 at the top feed point.
[0039] The remaining 73% of the vapor from separator 11 (stream 37 ) enters a work expansion machine 14 in which mechanical energy is extracted from this portion of the high pressure feed. The machine 14 expands the vapor substantially isentropically to the tower operating pressure, with the work expansion cooling the expanded stream 37 a to a temperature of approximately −69° F. [−56° C.] before it is supplied as feed to fractionation tower 17 at an upper mid-column feed point. The remaining separator liquid in stream 38 (if any) is expanded to the operating pressure of fractionation tower 17 by expansion valve 16 , cooling stream 38 a before it is supplied to fractionation tower 17 at a lower mid-column feed point.
[0040] The liquid product stream 42 exits the bottom of the tower at 130° F. [54° C.]. The residue gas (deethanizer overhead vapor stream 39 ) passes countercurrently to the incoming feed gas in heat exchanger 12 where it is heated from −122° F. [−86° C.] to −29° F. [−34° C.] (stream 39 a ) and in heat exchanger 10 where it is heated to 86° F. [30° C.] (stream 39 b ) as it provides cooling as previously described. The residue gas is then re-compressed in two stages, compressor 15 driven by expansion machine 14 and compressor 19 driven by a supplemental power source. After stream 39 d is cooled to 110° F. [43° C.] in discharge cooler 20 , the residue gas product (stream 39 e ) flows to the sales gas pipeline at 915 psia [6,307 kPa(a)].
[0041] A summary of stream flow rates and energy consumption for the process illustrated in FIG. 3 is set forth in the following table:
[0000]
TABLE III
(FIG. 3)
Stream Flow Summary - Lb. Moles/Hr [kg moles/Hr]
Stream
Methane
Ethane
Propane
Butanes+
Total
31
12,398
546
233
229
13,726
32
12,316
529
211
124
13,496
33
82
17
22
105
230
34
3,351
144
57
34
3,671
36
3,433
161
79
139
3,901
37
8,965
385
154
90
9,825
39
12,398
300
8
1
13,025
42
0
246
225
228
701
Recoveries*
Ethane
45.00%
Propane
96.51%
Butanes+
99.56%
Power
Residue Gas Compression
5,564 HP
[9,147 kW]
*(Based on un-rounded flow rates)
DESCRIPTION OF THE INVENTION
Example 1
[0042] In those cases where the C 2 component recovery level in the liquid product must be reduced (as in the FIG. 2 prior art process described previously, for instance), the present invention offers significant efficiency advantages over the prior art process depicted in FIG. 2 . FIG. 4 illustrates a flow diagram of the FIG. 2 prior art process that has been adapted to use the present invention. The operating conditions of the FIG. 4 process have been adjusted as shown to reduce the ethane content of the liquid product to the same level as that of the FIG. 2 prior art process. The feed gas composition and conditions considered in the process presented in FIG. 4 are the same as those in FIG. 2 . Accordingly, the FIG. 4 process can be compared with that of the FIG. 2 process to illustrate the advantages of the present invention.
[0043] Most of the process conditions shown for the FIG. 4 process are much the same as the corresponding process conditions for the FIG. 2 process. The main differences are the disposition of flash expanded substantially condensed stream 36 b and column overhead vapor stream 39 . In the FIG. 4 process, substantially condensed stream 36 a is flash expanded through expansion valve 13 to slightly above the operating pressure (approximately 402 psia [2,774 kPa(a)]) of fractionation tower 17 . During expansion a portion of the stream may be vaporized, resulting in cooling of the total stream. In the process illustrated in FIG. 4 , the expanded stream 36 b leaving expansion valve 13 reaches a temperature of −138° F. [−94° C.] before it is directed into a heat and mass transfer means inside rectifying section 117 a of processing assembly 117 . This heat and mass transfer means may be comprised of a fin and tube type heat exchanger, a plate type heat exchanger, a brazed aluminum type heat exchanger, or other type of heat transfer device, including multi-pass and/or multi-service heat exchangers. The heat and mass transfer means is configured to provide heat exchange between a combined vapor stream flowing upward through one pass of the heat and mass transfer means, and the flash expanded substantially condensed stream 36 b flowing downward, so that the combined vapor stream is cooled while heating the expanded stream. As the combined vapor stream is cooled, a portion of it is condensed and falls downward while the remaining combined vapor stream continues flowing upward through the heat and mass transfer means. The heat and mass transfer means provides continuous contact between the condensed liquid and the combined vapor stream so that it also functions to provide mass transfer between the vapor and liquid phases, thereby providing rectification of the combined vapor stream. The condensed liquid from the bottom of the heat and mass transfer means is directed to separator section 117 b of processing assembly 117 .
[0044] The flash expanded stream 36 b is further vaporized as it provides cooling and partial condensation of the combined vapor stream, and exits the heat and mass transfer means in rectifying section 117 a at −105° F. [−76° C.]. The heated flash expanded stream discharges into separator section 117 b of processing assembly 117 and is separated into its respective vapor and liquid phases. The vapor phase combines with overhead vapor stream 39 to form the combined vapor stream that enters the heat and mass transfer means in rectifying section 117 a as previously described, and the liquid phase combines with the condensed liquid from the bottom of the heat and mass transfer means to form combined liquid stream 152 . Combined liquid stream 152 leaves the bottom of processing assembly 117 and is pumped to higher pressure by pump 21 so that stream 152 a at −102° F. [−75° C.] can enter fractionation column 17 at the top feed point. The vapor remaining from the cooled combined vapor stream leaves the heat and mass transfer means inside rectifying section 117 a of processing assembly 117 at −117° F. [−83° C.] as cold residue gas stream 151 , which is then heated and compressed as described previously for stream 39 in the FIG. 2 process.
[0045] A summary of stream flow rates and energy consumption for the process illustrated in FIG. 4 is set forth in the following table:
[0000]
TABLE IV
(FIG. 4)
Stream Flow Summary - Lb. Moles/Hr [kg moles/Hr]
Stream
Methane
Ethane
Propane
Butanes+
Total
31
12,398
546
233
229
13,726
32
12,318
529
212
125
13,499
33
80
17
21
104
227
34
3,570
153
61
36
3,912
36
3,650
170
82
140
4,139
37
8,748
376
151
89
9,587
39
9,525
856
31
4
10,699
152
777
485
112
144
1,578
151
12,398
541
1
0
13,260
42
0
5
232
229
466
Recoveries*
Propane
99.65%
Butanes+
100.00%
Power
Residue Gas Compression
5,565 HP
[9,149 kW]
*(Based on un-rounded flow rates)
[0046] A comparison of Tables II and IV shows that, compared to the prior art, the present invention improves propane recovery from 93.60% to 99.65% and butane+recovery from 99.12% to 100.00%. The economic impact of these improved recoveries is significant. Using an average incremental value $1.08/gallon [ 214/m 3 ] for hydrocarbon liquids compared to the corresponding hydrocarbon gases, the improved recoveries represent more than US$1,120,000 [ 835,000] of additional annual revenue for the plant operator. Comparison of Tables II and IV further shows that these increased product yields were achieved using the same power as the prior art. In terms of the recovery efficiency (defined by the quantity of C 3 components and heavier components recovered per unit of power), the present invention represents more than a 3% improvement over the prior art of the FIG. 2 process.
[0047] The improvement in recovery efficiency provided by the present invention over that of the prior art of the FIG. 2 process is primarily due to the indirect cooling of the column vapor provided by flash expanded stream 36 b in rectifying section 117 a of processing assembly 117 , rather than the direct-contact cooling that characterizes stream 36 b in the prior art process of FIG. 2 . Although stream 36 b is quite cold, it is not an ideal reflux stream because it contains significant concentrations of the C 3 components and C 4 + components that deethanizer 17 is supposed to capture, resulting in losses of these desirable components due to equilibrium effects at the top of column 17 for the prior art process of FIG. 2 . For the present invention shown in FIG. 4 , however, there are no equilibrium effects to overcome because there is no direct contact between flash expanded stream 36 b and the combined vapor stream to be rectified.
[0048] The present invention has the further advantage of using the heat and mass transfer means in rectifying section 117 a to simultaneously cool the combined vapor stream and condense the heavier hydrocarbon components from it, providing more efficient rectification than using reflux in a conventional distillation column. As a result, more of the C 3 components and heavier hydrocarbon components can be removed from the combined vapor stream using the refrigeration available in expanded stream 36 b than is possible using conventional mass transfer equipment and conventional heat transfer equipment.
[0049] The present invention offers two other advantages over the prior art in addition to the increase in processing efficiency. First, the compact arrangement of processing assembly 117 of the present invention replaces three separate equipment items in the prior art of U.S. Pat. No. 4,854,955 (heat exchanger 23, the upper absorbing section in the top of distillation column 24, and reflux drum 26 in FIG. 4 of U.S. Pat. No. 4,854,955) with a single equipment item (processing assembly 117 in FIG. 4 of the present invention). This reduces the plot space requirements and eliminates the interconnecting piping, reducing the capital cost of modifying a process plant to use the present invention. Second, elimination of the interconnecting piping means that a processing plant modified to use the present invention has far fewer flanged connections compared to the prior art of U.S. Pat. No. 4,854,955, reducing the number of potential leak sources in the plant. Hydrocarbons are volatile organic compounds (VOCs), some of which are classified as greenhouse gases and some of which may be precursors to atmospheric ozone formation, which means the present invention reduces the potential for atmospheric releases that may damage the environment.
[0050] One additional advantage of the present invention is how easily it can be incorporated into an existing gas processing plant to effect the superior performance described above. As shown in FIG. 4 , only two connections (commonly referred to as “tie-ins”) to the existing plant are needed: for flash expanded substantially condensed stream 36 b (represented by the dashed line between stream 36 b and stream 152 a that is removed from service), and for column overhead vapor stream 39 (represented by the dashed line between stream 39 and stream 151 that is removed from service). The existing plant can continue to operate while the new processing assembly 117 is installed near fractionation tower 17 , with just a short plant shutdown when installation is complete to make the new tie-ins to these two existing lines. The plant can then be restarted, with all of the existing equipment remaining in service and operating exactly as before, except that the product recovery is now higher with no increase in residue gas compression power.
Example 2
[0051] The present invention also offers advantages when product economics favor rejecting only a portion of the C 2 components to the residue gas product. The operating conditions of the FIG. 4 process can be altered as illustrated in FIG. 5 to increase the ethane content of the liquid product to the same level as that of the FIG. 3 prior art process. The feed gas composition and conditions considered in the process presented in FIG. 5 are the same as those in FIG. 3 . Accordingly, the FIG. 5 process can be compared with that of the FIG. 3 process to further illustrate the advantages of the present invention.
[0052] Most of the process conditions shown for the FIG. 5 process are much the same as the corresponding process conditions for the FIG. 3 process. The main differences are again the disposition of flash expanded substantially condensed stream 36 b and column overhead vapor stream 39 . In the FIG. 5 process, substantially condensed stream 36 a is flash expanded through expansion valve 13 to slightly above the operating pressure (approximately 390 psia [2,691 kPa(a)]) of fractionation tower 17 . During expansion a portion of the stream may be vaporized, resulting in cooling of the total stream. In the process illustrated in FIG. 5 , the expanded stream 36 b leaving expansion valve 13 reaches a temperature of −141° F. [−96° C.] before it is directed into the heat and mass transfer means inside rectifying section 117 a of processing assembly 117 . As the combined vapor stream flows upward through one pass of the heat and mass transfer means and is cooled, a portion of it is condensed and falls downward while the remaining combined vapor stream continues flowing upward. The heat and mass transfer means provides continuous contact between the condensed liquid and the combined vapor stream so that it also functions to provide mass transfer between the vapor and liquid phases, thereby providing rectification of the combined vapor stream. The condensed liquid from the bottom of the heat and mass transfer means is directed to separator section 117 b of processing assembly 117 .
[0053] The flash expanded stream 36 b is further vaporized as it provides cooling and partial condensation of the combined vapor stream, and exits the heat and mass transfer means in rectifying section 117 a at −136° F. [−93° C.]. The heated flash expanded stream discharges into separator section 117 b of processing assembly 117 and is separated into its respective vapor and liquid phases. The vapor phase combines with overhead vapor stream 39 to form the combined vapor stream that enters the heat and mass transfer means in rectifying section 117 a as previously described, and the liquid phase combines with the condensed liquid from the bottom of the heat and mass transfer means to form combined liquid stream 152 . Combined liquid stream 152 leaves the bottom of processing assembly 117 and is pumped to higher pressure by pump 21 so that stream 152 a at −133° F. [−92° C.] can enter fractionation column 17 at the top feed point. The vapor remaining from the cooled combined vapor stream leaves the heat and mass transfer means inside rectifying section 117 a of processing assembly 117 at −128° F. [−89° C.] as cold residue gas stream 151 , which is then heated and compressed as described previously for stream 39 in the FIG. 3 process.
[0054] A summary of stream flow rates and energy consumption for the process illustrated in FIG. 5 is set forth in the following table:
[0000]
TABLE V
(FIG. 5)
Stream Flow Summary - Lb. Moles/Hr [kg moles/Hr]
Stream
Methane
Ethane
Propane
Butanes+
Total
31
12,398
546
233
229
13,726
32
12,317
529
212
124
13,497
33
81
17
21
105
229
34
3,632
156
63
37
3,980
36
3,713
173
84
142
4,209
37
8,685
373
149
87
9,517
39
10,689
425
12
1
11,435
152
2,004
298
95
143
2,627
151
12,398
300
1
0
13,017
42
0
246
232
229
709
Recoveries*
Ethane
45.00%
Propane
99.65%
Butanes+
100.00%
Power
Residue Gas Compression
5,565 HP
[9,149 kW]
*(Based on un-rounded flow rates)
[0055] A comparison of Tables III and V shows that, compared to the prior art, the present invention improves propane recovery from 96.51% to 99.65% and butane+recovery from 99.56% to 100.00%. The economic impact of these improved recoveries is significant. Using an average incremental value $0.74/gallon [ 145/m 3 ] for hydrocarbon liquids compared to the corresponding hydrocarbon gases, the improved recoveries represent more than US$575,000 [ 430,000] of additional annual revenue for the plant operator. Comparison of Tables III and V further shows that these increased product yields were achieved using the same power as the prior art. In terms of the recovery efficiency (defined by the quantity of C 3 components and heavier components recovered per unit of power), the present invention represents nearly a 2% improvement over the prior art of the FIG. 3 process.
[0056] The FIG. 5 embodiment of the present invention provides the same advantages related to processing efficiency and the compact arrangement of processing assembly 117 as the FIG. 4 embodiment. The FIG. 5 embodiment of the present invention overcomes the equilibrium limitations associated with expanded stream 36 b in the prior art FIG. 3 process to remove the heavier components from the column overhead vapor via indirect cooling and simultaneous mass transfer in rectifying section 117 a of process assembly 117 . The FIG. 5 embodiment of the present invention also replaces the three separate equipment items in the prior art of the U.S. Pat. No. 4,854,955 process with a single equipment item (processing assembly 117 in FIG. 5 ). This reduces the plot space requirements and eliminates the interconnecting piping, reducing the capital cost to modify an existing process plant to use this embodiment of the present invention while also reducing the potential for atmospheric releases of hydrocarbons that may damage the environment.
Example 3
[0057] The present invention can also be operated to recover the maximum amount of C 2 components in the liquid product. The operating conditions of the FIG. 4 process can be altered as illustrated in FIG. 6 to increase the ethane content of the liquid product to the same level as that of the FIG. 1 prior art process. The feed gas composition and conditions considered in the process presented in FIG. 6 are the same as those in FIG. 1 . Accordingly, the FIG. 6 process can be compared with that of the FIG. 1 .
[0058] Most of the process conditions shown for the FIG. 6 process are much the same as the corresponding process conditions for the FIG. 1 process. The main differences are again the disposition of flash expanded substantially condensed stream 36 b and column overhead vapor stream 39 . In the FIG. 6 process, substantially condensed stream 36 a is flash expanded through expansion valve 13 to slightly above the operating pressure (approximately 396 psia [2,731 kPa(a)]) of fractionation tower 17 . During expansion a portion of the stream may be vaporized, resulting in cooling of the total stream. In the process illustrated in FIG. 6 , the expanded stream 36 b leaving expansion valve 13 reaches a temperature of −140° F. [−96° C.] before it is directed into the heat and mass transfer means inside rectifying section 117 a of processing assembly 117 . As the combined vapor stream flows upward through one pass of the heat and mass transfer means and is cooled, a portion of it is condensed and falls downward while the remaining combined vapor stream continues flowing upward. The heat and mass transfer means provides continuous contact between the condensed liquid and the combined vapor stream so that it also functions to provide mass transfer between the vapor and liquid phases, thereby providing rectification of the combined vapor stream. The condensed liquid from the bottom of the heat and mass transfer means is directed to separator section 117 b of processing assembly 117 .
[0059] The flash expanded stream 36 b is further vaporized as it provides cooling and partial condensation of the combined vapor stream, and exits the heat and mass transfer means in rectifying section 117 a at −141° F. [−96° C.]. (Note that the temperature of stream 36 b drops slightly as it is heated, due to the pressure drop through the heat and mass transfer means and the resulting vaporization of some of the liquid methane contained in the stream.) The heated flash expanded stream discharges into separator section 117 b of processing assembly 117 and is separated into its respective vapor and liquid phases. The vapor phase combines with overhead vapor stream 39 to form the combined vapor stream that enters the heat and mass transfer means in rectifying section 117 a as previously described, and the liquid phase combines with the condensed liquid from the bottom of the heat and mass transfer means to form combined liquid stream 152 . Combined liquid stream 152 leaves the bottom of processing assembly 117 and is pumped to higher pressure by pump 21 so that stream 152 a at −141° F. [−96° C.] can enter fractionation column 17 at the top feed point. The vapor remaining from the cooled combined vapor stream leaves the heat and mass transfer means inside rectifying section 117 a of processing assembly 117 at −139° F. [−95° C.] as cold residue gas stream 151 , which is then heated and compressed as described previously for stream 39 in the FIG. 1 process.
[0060] A summary of stream flow rates and energy consumption for the process illustrated in FIG. 6 is set forth in the following table:
[0000]
TABLE VI
(FIG. 6)
Stream Flow Summary - Lb. Moles/Hr [kg moles/Hr]
Stream
Methane
Ethane
Propane
Butanes+
Total
31
12,398
546
233
229
13,726
32
12,200
503
183
82
13,278
33
198
43
50
147
448
34
3,784
156
57
25
4,118
36
3,982
199
107
172
4,566
37
8,416
347
126
57
9,160
39
12,265
55
5
1
12,508
152
3,854
198
107
172
4,432
151
12,393
56
5
1
12,642
42
5
490
228
228
1,084
Recoveries*
Ethane
89.79%
Propane
98.03%
Butanes+
99.71%
Power
Residue Gas Compression
5,569 HP
[9,155 kW]
*(Based on un-rounded flow rates)
[0061] A comparison of Tables I and VI shows that the present invention achieves essentially the same recovery levels as the prior art when the process is operated to recover the maximum amount of C 2 components. When operated in this manner, the temperature driving force for indirect cooling and simultaneous mass transfer in rectifying section 117 a of process assembly 117 is very low because the temperature of column overhead stream 39 is almost the same as the temperature of flash expanded stream 36 b , reducing the effectiveness of rectifying section 117 a . Although there is no improvement in the component recoveries compared to the prior art when the present invention is operated in this manner, there is no decline either. This means there is no penalty when economics favor operating the plant to recover the maximum amount of C 2 components in the liquid product, but the plant has all the advantages described previously for Examples 1 and 2 when economics favor operating the plant to reject some or all of the C 2 components to the residue gas product.
Other Embodiments
[0062] Some circumstances may favor also mounting the liquid pump inside the processing assembly to further reduce the number of equipment items and the plot space requirements. Such an embodiment is shown in FIG. 7 , with pump 121 mounted inside processing assembly 117 as shown to send the combined liquid stream from separator section 117 b to the top feed point of column 17 via conduit 152 . The pump and its driver may both be mounted inside the processing assembly if a submerged pump or canned motor pump is used, or just the pump itself may be mounted inside the processing assembly (using a magnetically-coupled drive for the pump, for instance). For either option, the potential for atmospheric releases of hydrocarbons that may damage the environment is reduced still further.
[0063] Some circumstances may favor locating the processing assembly at a higher elevation than the top feed point on fractionation column 17 . In such cases, it may be possible for combined liquid stream 152 to flow to the top feed point on fractionation column 17 by gravity head as shown in FIG. 8 , eliminating the need for pump 21 / 121 shown in the FIGS. 4 through 7 embodiments.
[0064] The present invention provides improved recovery of C 3 components and heavier hydrocarbon components per amount of utility consumption required to operate the process. An improvement in utility consumption required for operating the process may appear in the form of reduced power requirements for compression or re-compression, reduced power requirements for external refrigeration, reduced energy requirements for supplemental heating, or a combination thereof.
[0065] While there have been described what are believed to be preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto, e.g. to adapt the invention to various conditions, types of feed, or other requirements without departing from the spirit of the present invention as defined by the following claims. | A process and an apparatus are disclosed for a compact processing assembly to improve the recovery of C 2 (or C 3 ) and heavier hydrocarbon components from a hydrocarbon gas stream. The preferred method of separating a hydrocarbon gas stream generally includes producing at least a substantially condensed first stream and a cooled second stream, expanding both streams to lower pressure, and supplying the streams to a fractionation tower. In the process and apparatus disclosed, the expanded first stream is heated to form a vapor fraction and a liquid fraction. The vapor fraction is combined with the tower overhead vapor, directed to a heat and mass transfer means inside a processing assembly, and cooled and partially condensed by the expanded first stream to form a residual vapor stream and a condensed stream. The condensed stream is combined with the liquid fraction and supplied to the tower at its top feed point. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a color balance indicating device for use in color printing for the determination of a combination of color filters for providing a print having an optimum color balance.
2. Prior Art
For the convenience of being used in a dark chamber along with a color enlarger, prior art color balance indicating devices are equipped with a large size meter and are designed to be operated with an AC power source, thus resulting in increased size and cost of the device itself. Moreover, color printing has hitherto been left exclusively to professional photographers, and so, prior art color balance indicating devices are designed to meet the demands of such professionals. This constitutes one of the factors that make prior art color enlarging devices larger in size and expensive.
A color enlarger easy to be handled even by an amateur has recently been marketed. Notwithstanding, no accessible color balance indicating device is available.
It is those unskilled in the color printing art that want such a color balance indicating device.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a color balance indicating device reduced in size and price to an extent that it is easily accessible to the amateur photographer.
There is provided according to the present invention a less expensive color balance indicating device of small size, wherein indication of various modes of setting and adjustment is achieved by light-emitting indication bodies, thereby dispensing with meters that have been incorporated in prior art devices.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an electric circuit incorporated in the device of the present invention;
FIG. 2 shows the external appearance, as a whole, of a mechanical part of the device;
FIG. 3 is a fragmentary vertical cross-sectional view of a portion of the device;
FIG. 4 is a fragmentary perspective view of the device, partly shown in cross section;
FIG. 5 is a fragmentary perspective view of a color enlarger; and
FIG. 6 is a block diagram of an electric circuit according to another embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1 showing a first embodiment of an electric circuit incorporated in the device of the present invention, one of a plurality of color filters such as red, blue and green filters R, B and G is selectively positioned in front of light receiving element P, such as a photodiode. The color filters serve to impart to light receiving element P a photosensitivity corresponding to the spectral sensitivity characteristic of a photosensitive layer of each primary color (hereinafter referred to as a three-primary color spectral sensitivity) of a printing sheet. Exposure-time measuring filter F imparts an overall spectral sensitivity characteristic (the total value of the three-primary color spectral sensitivities) of a printing sheet, or a visual sensitivity characteristic thereof, to light receiving element P with the measurement of an exposure time. Light receiving element P is connected between the input terminals of operational amplifier A, the output of which is in turn fed back through a logarithmically converting diode D to one input terminal of the amplifier itself, whereby there is formed light measuring circuitry for generating at output terminal a an output proportional to the logarithmic value of light incident on light receiving element P.
Shown at VLo is a level adjusting, first variable resistor, to one terminal of which are switchably connected a fixed resistor VL, a second variable resistor VY and a third variable resistor VM. The connection of these resistors to the one resistor terminal is alternatively selected by changing-over switch S, which is adapted to be changed over from one terminal to another according to a selected color filter. In this connection, changing-over switch S connects fixed resistor VL to constant current source I 1 when red filter R is positioned in front of light receiving element P; connects second variable resistor VY to the source when blue filter B is positioned in front of light receiving element P; connects third variable resistor to the source I 1 for green filter G; and connects a fourth variable resistor VE to the source I 1 for exposure-time measuring filter F. Variable resistor VE is connected in parallel to a series connection of first variable resistor VLo and one of resistors VL, VY, VY', VM or VM'. rB is a biasing, fixed resistor.
Transistor T 1 is connected by the base thereof to output terminal a of the light measuring circuitry, and transistor T 2 is connected by the base thereof to output terminal b of an adjusting circuit including first through fourth variable resistors VLo, VY, VM and VE and fixed resistors VL and rB. Transistors T 1 and T 2 are connected by their emitters to common constant current source I 2 , thereby constituting a differential amplifying circuit, to the output terminals of which are connected light-emitting diodes L 1 and L 2 , respectively. The differential amplifying circuit is so arranged that in case a difference in input between transistors T 1 and T 2 is held in equilibrium, at which the above difference remains below a given value, then light-emitting diodes L 1 and L 2 are both turned on to emit light. If an input to transistor T 1 is higher than a given value, light-emitting diode L 1 alone is turned on to emit light, and if the reverse is the case, light-emitting diode L 2 alone emits light.
FIGS. 2 through 4 illustrate the external appearance and structure of a mechanical portion of the device, in which the circuit of FIG. 1 is to be incorporated. In the front end portion of the top surface of casing 1 is provided light receiving window 2 for light receiving diode P. Shown at 6 is an indication window, through which the light from light-emitting diodes L 1 and L 2 is observed, and at 4 a measuring subject selection dial, on the top surface of which is provided indicia 4a which is respectively aligned with a series of measuring subject indication marks 5 inscribed on the top surface of casing 1. The selection dial is rigidly mounted on shaft 10 journaled by a bearing 8, which in turn is rigidly secured to a printed circuit board 14, in the manner shown in FIGS. 3 and 4. Rigidly mounted on shaft 10 are filter plate 12 for carrying red, blue, green and exposure-time measuring filters R, B, G and F, and support plate 18 for supporting sliding contact 16 of change-over switch S, which contact is adapted to slide on printed circuit board 14. Printed circuit board 14 is rigidly secured to casing 1 by a known means (not shown). On printed circuit board 14 is printed the major portion of the electric circuit of FIG. 1, and respective fixed terminals SL, SY, SM and SE of change-over switch S are formed thereon. Light receiving element P is also supported on printed circuit board 14.
The series of measuring subject indication marks 5 include: mark CN representing that red filter R is positioned in front of light receiving element P and movable contact 16 of change-over switch S is connected to fixed resistor VL for setting a reference level condition with respect to a cyanine filter of a color enlarger; mark Y for selecting a yellow filter of the color enlarger, at which blue filter B is selected and the circuitry of second variable resistor VY is completed; mark M for determining a magenta filter of the color enlarger, at which green filter G and third variable resistor VM are respectively selected; mark E for setting an exposure-level measuring condition, at which exposure-time measuring filter F and fourth variable resistor VE are respectively selected; mark OFF for cutting off the supply of current from the power source; and mark CP representing a set position for selecting another red filter R P with a view to meeting the spectral sensitivity of a red sensitive layer of a printing sheet in the case where it is desired to produce a positive print from a color positive. Shown at 20 is a warning sign window, under which is disposed a warning lamp adapted to be turned on when the light incident on light receiving element P is below a given level, so as to inform the operator of the light level. The warning lamp is connected by controlling or amplifying circuitry (not shown) to output terminal a of the light measuring circuitry.
Shown at 22 is a level-setting knob for adjusting first variable resistor VLo, and at 24 and 26 are holes for receiving therein a screw-driver for rotating adjusting screws for second and third variable resistors VY and VM. In this embodiment, a screw-driver 28 removably fitted in casing 1 is inserted in hole 24 or 26 so as to turn either of the adjusting screws in the casing. Shown at 30 is a memory stage change-over switch for connecting second and third variable resistors VY, VM, and fifth and sixth variable resistors VY', VM' alternatively to the adjusting circuitry. Fifth and sixth variable resistors VY' and VM' are used for selecting between a yellow filter and a magenta filter, like second and third variable resistors VY and VM. In practice, second and third variable resistors VY and VM, for example, are used for producing a print from a human figure picture, and fifth and sixth variable resistors VY' and VM' are used for producing a print from a landscape picture. Shown at 25 and 27 are holes for receiving therein the screw-driver for turning adjusting screws for fifth and sixth variable resistors VY' and VM'.
An exposure-time measuring knob 32 is adapted to be turned relative to casing 1 so as to adjust fourth variable resistor VE. Index graduation disc 34 is arranged to be turned usually integrally with knob 32. Exposure-time graduation disc 36, having a series of exposure-time graduations 36a along the outer circumference thereof, is fitted rotatably with proper friction on a shaft (not shown), on which knob 32 is rigidly mounted. Exposure-time graduation disc 36 is normally turned integrally with knob 32, so as to be aligned with one of graduations 36a with an indicia 38 provided on the top surface of casing 1, thereby allowing an operator to read a selected exposure time. If knob 32 alone is rotated, with exposure-time graduation disc 36 held immovable by an operator's fingers, a resultant position of knob 32 relative to disc 36 is indicated by a combination of point 36b marked on exposure-time graduation disc 36 and one of the graduations on index graduation disc 34. Shown at 40 is a lid for a cell housing, which is slidable in arrow direction 40a into an open position.
Referring first to the manner of determining a color filter of the color enlarger, when it is desired to produce a positive print from a negative, a standard reference negative, which has a color balance employable as a reference and of which a proper exposure time relative to the color balance is known, is set in the color enlarger, and then the color balance indicating device is placed on an easel. At this juncture, when it is desired to reproduce a specific portion properly (for example, a picture of a shoulder of a human figure), the color balance indicating device needs to be set on the easel such that light receiving window 2 is positioned in the specific area of an image projected by means of the color enlarger onto the easel. When it is desired to reproduce the whole picture properly, such as in the case of a landscape picture, then light mixing element 42, consisting of a combination of a condenser lens and a light-diffusing disc, is positioned in the optical path of the projected light, so that the mixed light is measured by light receiving element P.
After the color balance indicating device has been set in the manner described, dial 4 is turned to align indicia 4a with mark CN, and level setting knob 22 is turned to set first variable resistor VLo at a point at which light-emitting diodes L 1 and L 2 are both turned on. Then, dial 4 is turned to align indicia 4a with mark Y, and screw-driver 28 is inserted in hole 24 (at this juncture, memory stage change-over switch 30 has been set to select second and third variable resistors VY and VM), to thereby turn the adjusting screw for second variable resistor VY, thereby setting the second variable resistor at a point at which light-emitting diodes L 1 and L 2 are both turned on. The dial is further turned to align indicia 4a with mark M, and third variable resistor VM is adjusted by means of screw-driver 28 to be set at a position at which light-emitting diodes L 1 and L 2 are both turned on.
After second and third variable resistors VY and VM have been set at positions respectively proper to the standard reference negative, the standard reference negative is replaced with a negative to be printed. Then, dial 4 is again turned to align its indicia with mark CN, and level setting knob 22 is turned to reset first variable resistor VLo at a position at which light-emitting diodes L 1 and L 2 are both turned on. Then, indicia 4a is aligned with mark Y, and the density of the yellow filter of the color enlarger is adjusted to a level at which light-emitting diodes L 1 and L 2 are both turned on. Further, indicia 4a is then brought into coincidence with mark M, and the density of the magenta filter of the color enlarger is adjusted to a level at which light-emitting diodes L 1 and L 2 are both turned on. The adjustment in density of the yellow and magenta filters of the color enlarger in the manner described above prior to a color printing, provides a print with optimum color balance. In case of positive-to-positive printing, indicia 4a has to be brought into coincidence with mark CP, but not with mark CN. However, the other procedures are quite the same as those for negative-to-positive printing.
The above description is based on the following principle. When a standard reference negative is set in the color enlarger and indicia 4a is aligned with mark CN, potentials Va1 and Vb1 at the points a and b in the electric circuit shown in FIG. 1 are represented by the following equations:
Va1=-A Log I.sub.R. . . (1)
Vb1=-(VLo+VL) . . . (2)
wherein A is representative of a constant of a logarithmically converting diode; Ir, the power of spectral light energy incident by way of red filter R to light receiving element P; VLo a terminal-to-terminal voltage at the first variable resistor; and VL a terminal-to-terminal voltage at fixed resistor VL. When light-emitting diodes L 1 and L 2 are both turned on, then:
Va1≈Vb1 . . . (3)
If the equations (1) and (2) are substituted for the equation (3), then:
VLo+VL=Log I.sub.R . . . (4)
In order that both light-emitting diodes L 1 and L 2 are turned on when indicia 4a is aligned with marks Y and M, respectively:
VLo+VY=A Log I.sub.B . . . (5)
VLo+VM=A Log I.sub.G . . . (6)
wherein VY and VM are representative of the terminal-to-terminal voltage at second and third variable resistors VY and VM, respectively; and I B , I G are the energy of light incident through the blue and green filters to light sensitive element P, respectively. From the equations (4), (5) and (6), the following equations are obtained: ##EQU1##
In terms that a negative to be printed is set in the color enlarger, and indicia 4a is brought into coincidence with marks CN, Y and M, respectively, a condition in which both light-emitting diodes L 1 and L 2 are turned on is expressed by the following equations, which correspond to the equations (4), (5) and (6), respectively:
VL'o+VL=A Log I'.sub.R . . . (9)
VL'o+VY=A Log I'.sub.B . . . (10)
VL'o+VM=A Log I'.sub.G . . . (11)
This indicates that fixed resistor VL, second and third variable resistors VY and VM remain unchangeable at the set positions for the standard reference negative, but the powers of spectral light energy incident on first variable resistor VLo and respective filters alone changes. From the equations (9), (10) and (9), (11), the following equations will apply: ##EQU2## By a comparison of equations (12), (13) with equations (7), (8), it is seen that equations (12) and (7) are the same in the right members thereof; the same is the case with equations (13) and (8); and the ratio among the powers of spectral energy I' R , I' B and I' G for negative to be printed is the same as that for the standard reference negative.
Referring to the measurement of an exposure time, dial 4 is turned to align indicia 4a with mark R, and knob 32 is turned, to thereby turn index graduation disc 34 as well as exposure-time graduation disc 36, whereby one of the exposure-time graduations 36a (for example, 10 second as shown in FIG. 2), is aligned with indicia 38, which graduation corresponds to a proper exposure time preset for a reference negative. Then, the standard reference negative is set in the color enlarger, and the light receiving window is positioned in registration with a desired measuring portion of a projected image. When it is desired to effect light measurement uniformly over the entire surface of the picture, such light measurement is easily achieved by using light mixing element 42 as in the case of determination of the filters. Thereafter, with exposure-time graduation disc 36 held immovable by an operator's fingers, knob 32 is turned until both light-emitting diodes L 1 and L 2 are turned on. Then, the reference negative is replaced with a negative to be printed, and exposure-time graduation disc 36 is turned by means of knob 32. An operator thus knows the real value of exposure time from the graduation at which both light-emitting diodes L 1 and L 2 are turned on, and can effect the printing at a proper exposure time according to the value thus indicated. In determination of an exposure time, if the output from the light measuring circuit is brought into balance with a terminal-to-terminal voltage at variable resistor VE, there is determined a proper exposure time for a negative to be printed, which corresponds to a proper exposure time for the standard reference negative. In case of determining a proper exposure time for a negative to be printed, it may be possible to maintain exposure-time graduation disc 36 immovable, and in turn to vary an aperture value of the color enlarger until both light-emitting diodes L 1 and L 2 are turned on.
In determining a color filter as well as in setting a level for a negative to be printed, it is basically possible to adjust the density of a cyanine filter of the color enlarger, instead of adjusting the first variable resistor, but the above-described procedures are preferable from the practical viewpoint.
FIG. 6 shows an electric circuit according to another embodiment of the present invention, wherein elements common to those in the electric circuit shown in FIG. 1 are identified with the same reference numerals. The electric circuit shown in FIG. 6 is based on the same principle as that in FIG. 1. In this circuit, the outputs of the light measuring circuitry and adjusting circuitry are fed as inputs to the input terminals of a first comparator circuit CP, and differential amplifying circuits T 1 and T 2 are arranged to control the lighting of light-emitting diodes L 1 and L 2 according to the difference between the outputs from comparator circuit CP and the reference level. This is for the purpose of providing an improved measuring accuracy. Transistor T 3 , second comparator circuit WP and constant voltage source I 3 form a warning circuit for giving a warning by extinguishing light-emitting diode L 3 when the power of energy of light incident on light sensitive element P is below a given level. Light-emitting diode L 3 is positioned to be observed by an operator through indication window 20 as shown in FIG. 2. Reference T 4 and Th represent a temperature compensating transistor and thermistor, respectively.
What has been described should be construed as illustrating the principle of the present invention, but not in a limitative sense. It is readily understood by those skilled in the art that various changes and modifications may be made. For example, the indication circuit may be so arranged that only a single light-emitting body be used for color balance indication, or one light-emitting element may be provided for each mode "OVER", "PROPER" or "UNDER". | A hand-carriable, compact color meter for indicating proper amount of adjustment of color compensation filters interposed in the light path of a color printer for the compensation of color balance of the light illuminating a film or the slide set on the printer. The color meter includes an indicating lamp, a photocell to be exposed to the light passing through the film or slide, a plurality of optical color filters selectively disposed in front of the photocell to provide the photocell with spectral sensitivities corresponding to the spectral sensitivity of the printing paper, a plurality of fixed or variable resistors selectable in correspondence to the selection of the color filter, and an electric circuit for actuating the indicating lamp in accordance with the relationship between the output of the light measuring circuit and a reference voltage commensurate with the selected one of the resistors. In a preferred embodiment, the color meter further includes a combination of a variable resistor and a filter for determination of exposure time. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to improvements in engines and more particularly, but not by way of limitation, to a crankcase vacuum system for improving the overall operation of the engine.
2. Description of the Prior Art
In an internal combustion engine, or the like, a crankcase is usually bolted or otherwise secured to the engine block for encasing the crank shaft and bearings and for maintaining a supply of suitable lubricating fluid or oil for operation of the pistons, and the like. During the operation of the engine, the lubricating fluid or oil frequently leaks across the piston rings and enters the combustion chamber, which not only fouls the combustion chamber but also reduces the operating efficiency of the engine.
SUMMARY OF THE INVENTION
The present invention contemplates a novel crankcase vacuum system which has been particularly designed for overcoming the foregoing disadvantages. The novel system comprises a check valve interposed between the fuel pump and intake manifold of the engine, and in communication with the crankcase breather. When the engine is started, the normal manifold vacuum quickly evacuates the crankcase through the check valve. The manifold vacuum will pull through the check valve at any time when the intake manifold vacuum is greater than the crankcase vacuum, and this condition is particularly present when the engine is at an idling speed or when the engine is at a part throttle operating condition. The fuel pump continuously draws a vacuum, particularly in these operating conditions, since it is driven by the engine.
During higher throttle operation of the engine, and particularly at a wide open throttle operation, the manifold vacuum will drop below the crankcase vacuum. When this happens, the check valve will automatically close and prevent the communication of the manifold pressure to the crankcase. The fuel pump continues to draw a vacuum, and since the check valve is closed, this fuel pump operation maintains the crankcase vacuum.
Of course, other means of producing a vacuum in the crankcase may be interposed in the system, either in series with or parallel with the manifold, crankcase and fuel pump. In any event, the creation of the vacuum in the crankcase provides an improved oil control, reduces oil consumption, maintains a cleaner condition for the combustion chamber, reduces detonation tendency, and allows a reduction of oil ring tension for reducing engine friction and increasing power output with a cooler running engine. The novel system is simple and efficient in operation and economical of installation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view, partly in section, illustrating a crankcase vacuum system embodying the invention and illustrating a check valve interposed between a fuel pump and an intake manifold and in communication with a crankcase breather.
FIG. 2 is an elevational view, partly in section, of a modified crankcase vacuum system embodying the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in detail, and particularly FIG. 1, a crankcase vacuum system is shown which comprises a suitable check valve 10 secured to a conduit or tube 12 extending to the intake manifold (not shown) of an internal combustion engine, or the like (not shown). Whereas the valve 10 may be of any well known type, as shown herein, the valve comprises a housing 14 having an inlet port 16 provided at one end thereof and an outlet port 18 provided at the opposite end thereof. The inlet port 16 is preferably in communication with the interior of the conduit 12 and suitable sealing means 20 may be interposed between the inlet 16 and conduit 12 for precluding leakage of fluid therebetween. A closure member 22 is movably disposed in the proximity of the outlet port 18 and is yieldable retained in engagement therewith in any suitable manner, such as by a helical spring 24 anchored between the closure member 22 and the inner periphery of the housing 14. The spring member 24 maintains the closure member 22 in a normal closed position against the outlet port 18 as is well known. However, when the pressure differential acting on the closure member 22 exceeds the force of the spring 24, the closure member 22 will be moved away from the port 18 for permitting the flow of fluid therethrough as will be hereinafter set forth.
The outlet port 18 is in communication with a suitable conduit 26 which is connected with a line or conduit 28 by a suitable Tee-fitting 30, or the like, as is well known. The conduit 28 extends between the usual fuel pump 32 and a line or conduit 34 communicating with the usual crankcase breather (not shown), and in this manner the check valve inlet port 22 is in communication with both the fuel pump 32 and the interior of the crankcase for a purpose as will be hereinafter set forth. The fuel pump 32 is provided with an outlet 36 which is open to the atmosphere.
When the engine (not shown) is initially started in the usual or well known manner, a vacuum is pulled or created in the intake manifold, and this vacuum is communicated to the valve 10 through the conduit 12 and the inlet port 16. When the vacuum in the intake manifold is greater than the vacuum present within the crankcase, or in other words, when the pressure within the intake manifold is less than the pressure within the crankcase, the pressure differential acting on the closure member 22 will overcome the force of the spring 24 and move the closure member away from the port 18 whereby communication is established between the intake manifold and the interior of the crankcase. The crankcase will thus be quickly evacuated through the check valve to establish a vacuum in the crankcase. The reduced pressure thus present in the crankcase decreases oil migration around the piston rings (not shown) and valve guides, thus greatly reducing accidental passage of the lubricating fluids into the combustion chamber.
Under any conditions wherein the vacuum present in the intake manifold is greater than the vacuum within the crankcase, the communication will be established between the manifold and crankcase through the valve 10. This condition is usually present at engine idling speeds, and at part throttle conditions.
When the intake manifold vacuum drops to a point below the crankcase vacuum, the closure member 22 will be urged in a direction toward the port 18 and maintained in a closed position thereagainst by the spring 24. This precludes the communication of the manifold pressure to the crankcase, and maintains the crankcase vacuum condition since the fuel pump draws a vacuum during its entire operation and the crankcase is in communication with the fuel pump 32 through the conduits 28 and 34.
Referring now to FIG. 2, a modified crankcase vacuum system is shown wherein a first check valve 40 generally similar to the valve 10 is interposed in a suitable conduit 42 which communicates between the intake manifold (not shown) and a closed circuit conduit 44. The conduit 44 extends from the inlet port 46 of the fuel pump 32 to the outlet port 48 thereof for circulation of fluid pressure as will be hereinafter set forth. A first branch line or conduit 50 is interposed in the circuit 44 and extends into communication with the interior of the crankcase (not shown), and a second check valve 52 is interposed in the circuit 44 outboard of the conduit 50 with respect to the fuel pump 32. A second branch conduit 54 is interposed in the circuit 44 and extends into communication with a third check valve 56 which in turn opens to a pitot tube 58 which empties into the usual exhaust collector 60.
In this embodiment of the invention, fluid pressure is circulated through the fuel pump in a closed pathway through the conduit 44. However, as in the first embodiment, a vacuum is pulled in the intake manifold upon energization of the engine (not shown), which opens the valve 40 and pulls fluid pressure in the direction indicated by the arrow 62. This pulls a vacuum in the crankcase (not shown) through the conduit 50 in the direction indicated by the arrow 64. As long as the pressure within the manifold is less than the pressure in the crankcase, the valve 40 will remain open for pulling the vacuum through the conduit 50. Of course, the pressure being evacuated from the crankcase may be exhausted through the circuit 44 in the direction of either arrow 66 or 68. The pressure moving in the direction of the arrow 66 passes through the open valve 52 for movement through the open valve 56 to discharge through the pitot tube 58 into the exhaust collector 60. Of course, the outlet 48 is also in communication with the valve 56 wherein exhaust from the fuel pump 32 may pass through the valve and into the pitot tube 58 for discharge through the exhaust collector 60.
When pressure conditions in the pitot tube 58 and in the downstream side of the valve 52 exceed the pressure being evacuated from the crankcase, the valve will automatically close, thus assuring that the vacuum condition in the crankcase will be maintained throughout operation of the engine. The valve 56 will close only when the pressure in the pitot tube 58 exceeds the pressure at the outlet 48 of the pump.
As hereinbefore set forth, the novel crankcase vacuum system improves oil control, reduces oil consumption, and facilitates maintenance of a clean operating condition in the combustion chamber. In addition, oil ring tension can be reduced, which reduces engine friction, resulting in a higher power output and a cooler running engine. Furthermore, with the addition of the exhaust in the vacuum system, the capacity of the crankcase vacuum system is boosted or increased, thus enabling the system to handle higher concentrations or amounts of piston ring "blow by", or fluid leakage.
From the foregoing it will be apparent that the present invention provides a novel crankcase vacuum system wherein a vacuum is rapidly pulled or created within the crankcase upon initiation of engine operation, and maintained therein throughout the engine operation, thus reducing piston ring "blow by" or oil leakage around the piston rings which results in a cleaner condition for the combustion chamber and provides greater engine efficiency with less oil consumption.
Whereas the present invention has been described in particularly relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein may be made within the spirit and scope of this invention. | An engine crankcase vacuum system wherein a check valve is interposed between the intake manifold and the fuel pump and is in open communication with the crankcase breather of the engine in order to rapidly create and maintain a vacuum in the crankcase. The crankcase vacuum greatly reduces oil migration around the piston rings and valve guides of the engine in order to reduce oil consumption, decrease contamination of the combustion chamber from oil leakage, and reduce detonation tendency. The crankcase vacuum also allows a reduction in oil ring tension which in turn reduces engine friction, resulting in a high power output and cooler running engine during operation thereof. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims the benefit of and priority on German Patent Application No. 10 2014 017 478.6 having a filing date of 26 Nov. 2014.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The invention relates to a method for sorting laundry items, in particular dirty laundry items, wherein laundry items are taken individually from a delivered batch of laundry and the respective laundry item transferred to a transport system which transports the laundry item to a sorting station where the laundry item is deposited by the transport system at a dropping point which, on the basis of related information, corresponds to at least one sorting criterion of the laundry item.
[0004] 2. Prior Art
[0005] Laundry items, in particular dirty laundry items to be washed or laundry items to be finished, are sorted after delivery in a laundry so that they can be washed, finished or treated in some other way in a purposeful manner.
[0006] The laundry items, and above all the dirty laundry items, are usually delivered in batches, for example in laundry bags or laundry containers. The laundry items must therefore be separated before being sorted. In most cases, this is carried out manually.
[0007] The sorting operation which follows the separation of the laundry items is effected by way of information that can be gathered from the geometry, size, color and/or the type of fabric of the dirty laundry item. Other types of information are derived from the laundry items by an operator, for example by using a read device to transfer information from an information carrier located on the laundry item.
[0008] The sorting activities described above are expensive in terms of labor and time.
BRIEF SUMMARY OF THE INVENTION
[0009] The object of the present invention is to create a method for sorting laundry items, in particular dirty laundry items, which is automated at least for the most part, preferably completely automated.
[0010] A method for solving the aforementioned task comprises a method for sorting laundry items, in particular dirty laundry items, wherein laundry items are taken individually from a delivered batch of laundry and the respective laundry item transferred to a transport system which transports the laundry item to a sorting station where the laundry item is deposited by the transport system at a dropping point which, on the basis of related information, corresponds to at least one sorting criterion of the laundry item, characterized in that a surface profile of at least one laundry item of the delivered batch of laundry is determined, that at least on the basis of the surface profile a location is determined at which the laundry item can be gripped by a gripping means and that this location on the laundry item is gripped in a targeted manner by the gripping means.
[0011] This method is characterized in that a surface profile, in particular a topography, of the respective laundry item of the delivered batch of laundry is determined and, on the basis of this surface profile or topography, a location on the laundry item is identified at which it can and/or should be gripped by a gripping means of the transport system. The item of laundry is then gripped at this location by the gripping means in a targeted manner. This results in an automatic separation of the laundry item from the pile of laundry.
[0012] One advantageous option of the method provides that the gripping means having at least one high-speed servo axis is moved toward a significant location identified by the recorded surface profile or recorded topography of the laundry item. Such a high-speed servo axis can be formed by an electrically or pneumatically driven linear drive unit such as a pneumatic cylinder or a rack-and-pinion drive powered by an electric motor. Such linear drives are capable of achieving quite high acceleration and speed rates and consequently short transfer times. This results above all in short cycle times due to the identified position of the preferred location on the laundry item to grip as determined, in particular calculated, by imaging methods.
[0013] Preferably the method can be further refined by a position, calculated from the recorded surface profile or recorded topography of the laundry item, of a location that is intended or suited for the gripping of the laundry item. The gripping means can then be moved toward this location in a controlled, targeted manner, in particular on at least one high-speed servo axis for moving the gripping means. Here, too, it is possible to achieve short cycle times and a high sorting capacity.
[0014] According to another possible further development of the method, it is provided that the surface profile or the topography of the respective laundry item is recorded stereoscopically by at least one camera, preferably a number of cameras, at different positions. This makes it possible to record a three-dimensional image of the respective laundry item prior to and/or after the separating process. The use of electronic image processing makes it possible to identify automatically a location which is particularly easy to grip, preferably a location where the laundry item exhibits a significant curvature but also different characteristic features of the laundry item as a whole or at least a representative part of said laundry item.
[0015] Provision is preferably made that, on the basis of the recorded surface profile, in other words the topography from which the three-dimensional image of the laundry item can be determined, it is possible to calculate where a convenient or required location on the laundry item for gripping is situated and that the position of this location can be calculated in triaxial coordinates. After the targeted gripping or suction handling of the laundry item, it can then be pulled out of the pile of laundry and thereby deliberately separated out from the laundry.
[0016] The method can be designed such that, preferably after a laundry item has been separated out, the laundry item is graphically recorded by an imaging device, if possible including its topography or surface profile, and with the image of the laundry item recorded in this manner at least one sorting criterion of the laundry item is determined or derived. Accordingly, as least a number of sorting criteria for the laundry item can be reliably established automatically in a simple manner without the need of operating personnel.
[0017] The image of the laundry item recorded by the imaging device, particularly when it is a colored, three-dimensional image, can be preferably used to determine the shape, size, structure or type of fabric and/or the color of the laundry item and to derive therefrom at least one part of the sorting criteria of the laundry item.
[0018] Further, the method can be configured such that the laundry item is graphically recorded by the imaging device prior to its transfer or during its transfer on a fastening means of the transport system. This position is particularly suitable for making at least one image of the laundry item, from which at least one sorting criterion can be derived. As an alternative or in addition, the image recorded by the imaging device can be used to influence the transfer operation of the laundry item to the fastening means of the transport system, in particular to control or regulate it. This can thereby result in a more reliable automatic transfer of the laundry item from the separating station to the following transport system.
[0019] It is particularly advantageous to employ the image recorded by the imaging device for determining at least several sorting criteria of the laundry item and to control or regulate the transfer process of the laundry item to the transport system. This results in an appreciable increase in the sorting capacity because the preparations involved in sorting the laundry items, in particular the dirty laundry items, can be carried out not only fully automatically but also with short cycle times made possible by the automation.
BRIEF DESCRIPTION OF THE DRAWING
[0020] In the following, the invention will be described in more detail as based on the drawing. The single FIGURE of the drawing, FIG. 1 , shows a schematic view of one part of a sorting device for in particular dirty laundry items, namely the preparation of dirty laundry for sorting purposes.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] In this description it is assumed that the laundry items to be sorted are dirty laundry items that have been delivered to a laundry. Referring to FIG. 1 , the dirty laundry items 10 are first sorted before being washed, dried and, if appropriate, ironed and/or folded. The dirty laundry items 10 can be so-called shaped pieces, such as table linen, bed linen or the like, but can also be shaped pieces such as items of clothing, in particular workwear garments. The dirty laundry items 10 are usually delivered to the laundry unsorted in laundry bags or also in laundry containers.
[0022] In the shown exemplary embodiment, a pile containing a plurality of dirty laundry items 10 is fed by a conveyor, specifically a belt conveyor 11 in the FIGURE, from a laundry bag, for example, to a sorting station. In the FIGURE only a front part, i.e. the start, of the sorting station is shown. This is a separation device 12 , which is followed by the start of a transport system 13 , which transports separated dirty laundry items 10 to the appropriate dropping points of the sorting station, thereby sorting the items by dropping them at the dropping point corresponding to the sorting criterion of the respective dirty laundry item 10 .
[0023] The pile containing a plurality of dirty laundry items 10 , which are usually tossed together, and possibly also intertwined with each other, is transported by the belt conveyor 11 into the operating area of the separation device 12 and gripped by a clamp 14 of the separation device 12 and thereby separated. The shown separation device 12 has a linear and diagonally ascending elongated rail 14 , on which, as shown in the exemplary embodiment, two clamps 15 for the purposes of separation can be moved. The two clamps 15 alternately grip a dirty laundry item 10 from the pile containing a plurality of dirty laundry items 10 which still lies on the belt conveyor 11 . While one clamp 15 grips a dirty laundry item 10 at the lower end region of the rail 14 , the other clamp 15 at the top end region transfers a separated dirty laundry item 10 to a clamp 16 of the transport system 13 .
[0024] The separation device 12 is assigned an imaging device, which determines the surface profile or topography of the pile containing a plurality of dirty laundry items 10 located at the separation site. This imaging device is equipped with at least one camera 17 as suggested in the FIGURE. Preferably the imaging device has two or more cameras 17 , which are arranged at different positions in order to record and generate by stereoscopic means a three-dimensional picture of the pile containing a plurality of laundry items 10 . The image of the surface profile or topography of the pile of a plurality of laundry items 10 , recorded by preferably a plurality of cameras 17 , is then electronically evaluated by image processing in that a three-dimensional surface model of at least one significant part of the dirty laundry item 10 is determined. This is used to determine which dirty laundry item 10 can best be gripped and to detect which location on it is most suitable for being gripped by the clamp 15 . Such a location is characterized by a small radius of curvature, a distinctive curvature or a large curvature gradient. Preferably the dirty laundry item 10 chosen for separation has a fold, a crease, an edge or a corner at the detected location.
[0025] At the location determined by image capture and image evaluation the clamp 15 of the separation device 12 grips the next dirty laundry item 10 to be drawn out of the pile containing a plurality of dirty laundry items 10 . By being run up along the rail 14 , the gripped dirty linen item 10 is pulled out of the pile and thereby separated from it.
[0026] The separated dirty laundry item 10 is run up the rail 14 by the clamp 15 until it reaches the upper end region of the rail 14 . There the individual dirty laundry item 10 , which has been gripped by the clamp 15 at an arbitrary location, hangs down from the clamp 15 .
[0027] Another imaging device records the surface profile or the topography of the dirty laundry item 10 hanging down from the clamp 15 at the upper end region of the rail 14 . The FIGURE shows schematically only one camera 18 of the imaging device for recording the dirty laundry item 10 hanging down from the clamp 15 . Here a single camera 18 can be sufficient for recording a significant part of the surface profile of the dirty laundry item 10 , preferably one side of the same. It is also conceivable that here too a three-dimensional surface model, in particular the topography, of the dirty laundry item 10 hanging down from the clamp 15 is determined stereoscopically by employing a plurality of preferably identical cameras 18 . Preferably the cameras 18 or even only the one camera 18 constitute a camera 18 that can produce a color image of the dirty laundry item 10 .
[0028] The at least one camera 18 determines not only the surface profile or topography of the dirty laundry item 10 under the clamp 15 but also at least one sorting criterion relevant to the sorting process. This may involve the profile or shape, the size, the color and/or the fabric surface structure of the dirty laundry item 10 hanging down from the clamp 15 .
[0029] The surface profile or topography of the dirty laundry item 10 hanging down from the clamp 15 as recorded by at least one camera 18 can also be used to determine that location on the dirty laundry item 10 that is particularly suited for being gripped by the clamp 16 of the transport system 13 . This can involve an arbitrary location on the dirty laundry item 10 , but if necessary also a significant location such as an edge or corner of the dirty laundry item 10 . The dirty laundry item 10 is gripped by the clamp 16 of the transport system 13 at this location and transported along the transport system 13 to the dropping point corresponding to the sorting criterion in order to complete the sorting process.
[0030] It is conceivable that the transport system 13 or the clamp 16 of same is assigned a weighing mechanism which determines the weight of the dirty laundry item 10 hanging on the clamp 16 .
[0031] In the following, the method according to the invention will be described in more detail with reference being made to the FIGURE of the drawing:
[0032] The dirty laundry items 10 delivered to the laundry facilities are fed in batches or piles to the separation device 12 by the belt conveyor 11 to the start of the sorting station. In this process a pile of unsorted dirty laundry items 10 , which are tossed together and possibly intertwined with each other, arrives at the separation device 12 .
[0033] A three-dimensional image is recorded by preferably a plurality of cameras 17 of the surface structure or topography of the pile of dirty laundry items 10 on the belt conveyor 11 , with this image being used to calculate data of a three-dimensional surface model of the dirty laundry item 10 . A graphic image is recorded by at least two cameras 17 of the pile containing a plurality of dirty laundry items 10 from at least two different angles. A three-dimensional image of the pile of dirty laundry items 10 is thereby displayed, making it possible to determine three spatial coordinates. For this purpose, the three-dimensional coordinates X, Y and Z of each point or several points on the surface of the pile and/or of a single dirty laundry item 10 are calculated. The resulting three-dimensional image of the surface structure or topography of the pile of dirty laundry items 10 is electronically processed, preferably with a computer (not shown), data of the three-dimensional surface model are calculated and preferably also stored.
[0034] The cameras 17 can record images continuously in order to determine the surface profile or the topography of the dirty laundry items 10 . But it is also conceivable that pictures are recorded at regular intervals. What is decisive is that, before a dirty laundry item 10 is gripped from the pile, the topography or surface profile of the next dirty laundry item 10 to be gripped and separated has been determined.
[0035] Once image processing has determined the topography or surface profile of the visible dirty laundry items 10 located in the pile, a dirty laundry item 10 that is particularly suited for being gripped is identified and a location on this dirty laundry item 10 is determined which is particularly suited for being gripped and separated. This is preferably such a location at which the individual dirty laundry item 10 can be reliably gripped and drawn out of the pile containing a plurality of dirty laundry items 10 . A location on the dirty laundry item 10 that is particularly suitable for this purpose is one which has a small radius of curvature, in other words a distinctive curvature and/or a large curvature gradient, for example, a fold, a crease, an edge and/or a corner of the dirty laundry item 10 . For the purpose of determining said location, the topography or the surface profile of the image of the pile of dirty laundry items 10 taken by the camera, in particular of the laundry item that is the preferred one for being gripped, is evaluated such that, for respectively adjacent points, the angle between two tangents or tangential planes of these points is determined. If this angle is flat, for example, the dirty laundry item 10 has a large radius of curvature at this location. If, on the other hand, the angle is acute or if the tangents do not intersect at all, one can assume a small radius of curvature, in other words, a location that is appropriate for separating the dirty laundry item 10 .
[0036] Based on the location on the dirty laundry item 10 which is particularly suitable for being gripped, the electronically identified or calculated coordinates of the particularly suitable location for gripping are transmitted by the image analysis apparatus, in particular a computer, to a controller of the clamp 15 . By means of this controller the clamp is moved with its high-speed servo axis 15 precisely toward the location on dirty laundry item 10 that has been identified and calculated by image processing or image analysis.
[0037] If the determined surface profile or topography of the dirty laundry item 10 results in more than one location being identified as suitable for gripping, an evaluation is conducted as to which location is best suited, in particular situated at the shortest distance from the clamp 15 or which can be approached by the latter most quickly.
[0038] If necessary, provision can be made for detecting a specially defined location, for example, an edge or a corner of the dirty laundry item 10 . For the purpose of this detection, a library containing a large number of recorded significant locations, in particular corners and edges, that have been recorded by the cameras 17 of previous dirty laundry items 10 , can be stored in the image processing device or evaluation device, for example a computer, and used to make a comparison.
[0039] After the clamp 15 of the separation device 12 has gripped the preferred location of the dirty laundry item 10 that was identified by the at least one camera 17 and calculated by image processing, the clamp 15 is run up along the rail 14 with a high-speed servo axis, thereby pulling the dirty laundry item 10 it is holding out of the pile of a plurality of dirty laundry items 10 and thereby separating it from the pile. After the clamp 15 with the separated dirty laundry item 10 has been run up along the rail 14 to the end position at the opposite end of the rail 14 , the dirty laundry item 10 has been pulled out of the pile far enough that it hangs down freely from the clamp 15 . Here is where a transfer of dirty laundry item 10 from the clamp 15 to the clamp 16 of the transport system 13 takes place. At this transfer point the dirty laundry item 10 is also recorded graphically by at least one camera 17 in order to create an image of it. At this transfer point, it may be sufficient to record merely a two-dimensional image of the dirty laundry item 10 . But it is preferred that a three-dimensional image is stereoscopically recorded also at the point of transfer of the dirty laundry item 10 from the clamp 15 by means of clamp 16 of the transport system 13 , specifically and preferably a color image, which allows conclusions to be made concerning the surface profile and topography of the dirty laundry item 10 hanging on the clamp 15 . This therefore makes it possible to detect a location on the dirty laundry item 10 which is particularly suitable for the transfer of the dirty laundry item 10 to the transport system 13 , in particular for being gripped by the clamp 16 .
[0040] At least one sorting criterion is also determined by the at least one camera 18 . One sorting criterion or also a plurality of sorting criteria can also be derived from a two-dimensional image of the dirty laundry item 10 at the transfer point to the clamp 16 . The sorting criteria can include the shape of the dirty laundry item 10 . For example, a determination can be made as to whether the dirty laundry item 10 is a shaped piece (such as a piece of clothing) or a piece of flat linen (for example, a bed sheet). Furthermore, as an alternative or in addition, the size of the dirty laundry item 10 , the surface structure of the dirty laundry item 10 , in particular of the fabric, can additionally be determined, from which, for example, the type of fabric of the dirty laundry item 10 can be known. If the at least one camera 18 is a color camera, the image it records can also provide further information about the color of the dirty laundry item 10 , in particular it can be established whether it is a piece of colored fabric. Alternatively or in addition, it is conceivable that the at least one recorded image of the dirty laundry item 10 can be used to determine whether this item has defects, such as holes, stains or is heavily soiled. Such laundry items can then be sorted out.
[0041] After a two- or three-dimensional image of the dirty laundry item 10 has been graphically recorded by the at least one camera 18 , the dirty laundry item 10 is gripped and removed by the clamp 16 of the transport system 13 at the location determined by corresponding image analysis. The image analysis determines this location in the same manner as described with respect to the camera 17 at the separation site. If necessary, the weight of the dirty laundry item 10 in the state in which it hangs on the clamp 16 , but also on the clamp 15 , can be determined. From this a further sorting criterion can be derived.
[0042] The determination of the topography or the surface profile of the dirty laundry item 10 using at least one camera 18 can, as an alternative, also be carried out after the dirty laundry item 10 has been gripped by the clamp 16 of the transport system 13 and hangs down from this clamp 16 .
[0043] The respective dirty laundry item 10 hanging on the clamp 16 is transported by the transport system 13 past the individual dropping points, being released from the clamp 16 , in other words dropped, at that dropping point which corresponds to the sorting criterion, or if appropriate, to a combination of a plurality of criteria, as previously determined by the imaging recording and evaluation processes. This leads to the sorted drop-off of the dirty laundry item 10 by the transport system 13 , with the dirty laundry item 10 landing in a container or also on a conveyor provided for the dirty laundry item 10 which corresponds to the at least one sorting criterion.
[0044] As described above, the individual dirty laundry items 10 are progressively separated from the pile containing a plurality of dirty laundry items 10 and subsequently sorted. Due to the processing and evaluation of the images recorded by the cameras 17 and 18 , preferably three-dimensional surface profiles or topographies, the separating process as well as at least one portion of the sorting process are automated, and can therefore be performed on a fully automatic basis.
LIST OF DESIGNATIONS
[0000]
10 dirty laundry item
11 belt conveyor
12 separation device
13 transport system
14 rail
15 clamp
16 clamp
17 camera
18 camera | The sorting of laundry items, in particular dirty laundry items, has hitherto been carried out manually in most cases, which is costly in terms of personnel and time. High sorting capacities are therefore only possible with the corresponding personnel expenses. The invention provides that, at the start of sorting, specifically during their separation, and prior to their further transport to the individual sorting sites, the dirty laundry items are scanned by imaging techniques and, as a result of the appropriate image analysis, it is possible to determine the areas of the dirty laundry items to be preferably gripped and/or at least a number of sorting criteria, such as size and color. These measures result in a largely automated sorting procedure. These measures can be extended so as to achieve a fully automatic sorting procedure. | 3 |
FIELD OF INVENTION
This invention relates to a multimode heatsink for an electronic module which mounts to a printed circuit board.
BACKGROUND OF INVENTION
Present day electronic devices require special provisions for removing heat. Some prior art examples include adding heatsinks and other thermally conductive structures to the electronic device. It is also known to have air cooling for structures containing electronic devices.
More recently heatpipes have been employed to transfer heat from the device to a remote location where the heat is then removed by a heatsink, a fan, or any other appropriate device.
The cooling requirement, available physical space for the cooling solution, cost of the solution and the reliability requirement of the solution help determine the type of external cooling solution. Where the reliability and the cost of the cooling solution are the most important criteria for an application, a heatsink is an ideal candidate. It has been found, however, that when cooling requirements are stringent and available physical space is constrained in the height or z direction, a large thin heatsink is inadequate. Heatpipes have not found universal application because the heatpipe merely transfers the heat but does not dissipate the heat.
SUMMARY OF INVENTION
It is an object of the present invention to efficiently transfer heat from a heat source to all portions of a heatsink for more efficient dissipation. It is a further object of this invention to improve upon heatsinks by eliminating variation in temperature over the heatsink.
More specifically, it is an object of this invention to provide a heatpipe within a heatsink to efficiently transfer heat within the heatsink and to improve reliability and thermal performance.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages will occur to those skilled in the art from the following description of preferred embodiments and the accompanying drawings in which:
FIG. 1 is a three dimensional view of a heatsink mounted to an electronic module according to the present invention;
FIG. 1A is a cross-sectional view of the heatsink of FIG. 1;
FIG. 1B is a three dimensional view showing the side of the heatsink that is mounted to the electronic module;
FIG. 2 is a three dimensional view of a heatsink having several heatpipes and mounted to an electronic module which is mounted on a printed circuit board;
FIG. 3 is a partial cross section of the heatsink of FIG. 1 showing the groove therein for the heatpipe according to the present invention; and
FIG. 4 is another partial cross section view of the heatsink showing a modification of the groove therein for the heatpipe according to the present invention;
FIG. 5 is a partial cross section of the heatsink in which the heatpipe is flat or flattened to improve thermal contact with the module; and
FIG. 6 is a partial cross section of the heatsink in which the heatpipe is integral with the heatsink; e.g., the heatpipe is a hole within the heatsink.
DESCRIPTION OF THE INVENTION
With more specific regard now to FIG. 1, there is shown a heatsink 10 having a base 12 and fins 14 for heat dissipation. Within the base 12 a groove 16 is formed providing a channel within which a heatpipe 18 is located. In this embodiment the heatsink 10 and heatpipe 18 are attached by a thermal adhesive 20 to an electronic module 22 having pins 24 for connecting to a printed circuit board 26 (see FIG. 2). Electronic module 22 is a packaged integrated chip. It could also be an IC chip or discrete power component directly attached to heatsink 10 and heatpipe 18.
As seen in FIG. 1A the groove 16 in the base 12 is sized to allow the heatpipe 18 to contact the module 22 (FIG. 1) along the plane of base 12 via the adhesive layer 20 (FIG. 1). FIG. 1B shows the groove 16, extending from edge 28 to edge 30 of the heatsink 10. Area 31 is the area of contact between heatsink 16 and module 22. Heatpipe 18 transfers heat within heatsink 10 from area 31 to distant portions of heatsink 10 to reduce thermal gradients and provide more efficient cooling of module 22.
Referring now to FIG. 2, there is shown another embodiment of this invention having several grooves 32, 34, 36, 38 and 40 for heatpipes, three of which are in contact with module 42. Module 42 is electrically connected to printed circuit board 26.
In one embodiment, shown in FIG. 3, the groove 16 (or groove 32, 34, 36, 38, 40) is formed by an arcuate wall 46 and converging walls 48 and 50. In this groove construction the heatpipe 18 will rest on module 22 in the plane of base 12 (FIG. 1). Space 51 between heatpipe 18 and walls 46, 48, and 50 is filled with thermally conducting adhesive 58 to facilitate heat transfer from heatpipe 18 to heatsink 10. Groove 16 is made only slightly larger than heatpipe 18 to further facilitate heat transfer. Preferably groove 16 is sized so that at least 1/2 of the surface area of heatpipe 18 is in initimate contact with groove 16 to provide efficient heat transfer between heatpipe and heatsink. If groove 16 is made shallower than the diameter of heatpipe 18, in mounting module 22 to heatsink 10 heatpipe 18 will be flattened, increasing the area of contact 60 between module 22 and heatpipe 18 in the region where module 22 is located, as shown in FIG. 5. This improves heat transfer by providing a larger area of contact between module 22 and heatpipe 18 and more direct contact between heatpipe 18 and heatsink 10 along arcuate wall 50 of groove 16.
Groove 16 can also have parallel sidewalls 52 and 54 connected by arcuate wall 56, as shown in FIG. 6. In this form the heatpipe 18 is also provided within a thermally conductive adhesive 58 to transfer heat from the electronic module directly to heatpipe 18 and then to heatsink 10.
The construction shown in FIG. 3 has a half circle with an inverted wedge shaped channel or groove extruded in the base of the heatsink. The heatpipe diameter, its tolerances, and the straightness of the heatpipe along with the extrusion processes forming channel 16 will determine the radius of the half circle and the angle of the inverted wedge. Similarly, for the C-shaped channel of FIG. 4, the channel depth and width are determined by adding the tolerance of the heatpipe diameter and the straightness and die-cast process tolerances to the nominal diameter of the heatpipe.
The present invention is particularly applicable where the area of base 12 of heatsink 10 is at least four times that of the area of contact between module 22 and heatsink 10. The larger heatsink facilitates a larger heat dissipation from a module, and the heatpipes allow the large heatsink to operate more efficiently by facilitating heat transfer within the heatsink for a more uniform temperature in all portions of the large heatsink.
In assembling the heatpipe and heatsink, the groove 16 (or 32, 34, 36, 38, 40) is extruded or die-cast in the heatsink, and the groove 16 is then cleaned with a cleaning solution, such as isopropyl alcohol. Groove 16 is formed in heatsink 10 during extrusion of the heatsink at no extra cost. Heatpipe 18 is also a very low cost part. Thus, the cost of the integrated heatpipe and heatsink is low.
Thereafter a measured thermally conductive adhsive 58 (i.e. Loctite 384) is inserted into groove 16 and the heatpipe 18 is inserted from an end (FIG. 3) or from the base (FIG. 4) depending on the type of groove. Alternatively, heatpipe 18 can be brazed or soldered into groove 16. In the next step, a thermally conductive double sided adhesive tape 20 may be placed over the groove to contain heatsink 18 within groove 16. Sized equal to the surface area of contact with module 22, adhesive tape 20 can also be used to bond heatsink 10 to module 22. Before adhesive 58 cures the assembly is inverted whereupon heatpipe 18 will drop so that its surface will extend to the surface plane 12 of the heatsink 18 squeezing the adhesive to fill the groove 16 and to preclude any air gap above the heatpipe 18 in the groove 16. In the preferred embodiment the heatpipe is made of copper and the heatsink from aluminum whereby the mismatch of their coefficients of expansion is not large enough to affect this assembly. The heatsink can also be made of copper, but at higher cost. Alternatively heatpipe 18 can be brazed or soldered into groove 16. Heatpipe 18' can also be fabricated as a hole within heatsink 10 located at or near the surface of base 12 which contacts module 22 as shown in FIG. 6. This improves thermal transfer by eliminating adhesive 58.
Having now set forth a description of this invention and a method of assembly thereof it is now desired to set forth the scope of protection afforded by these Letters Patent in the form of appended claims. | A heatsink mounted to an electronic device having an area substantially greater than that of the device includes a heatpipe in the heatsink for transferring heat within the heatsink to reduce thermal gradients therein. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to the field of computer controlled and laser guided portable machines for machining parts or work-pieces and, in particular, to a machine that uses a laser position determination system to correct errors in the position of the machining head due to uncontrolled movements of the machine or work-piece.
[0003] 2. Description of Related Art
[0004] Computer controlled milling machines and the like are old in art. They generally consist of a very rigid rails to which is mounted a movable carriage containing a head for mounting a cutter or other tool. The work-piece to be machined is mounted on a very rigid platform and the head is moved thereover. Such machines are so rigid that the head and tool can be precisely positioned under the control of a computer.
[0005] Some machines, by the nature of their design, can not position the head and tool to a precise position and thus require supplemental alignment systems. For example, U.S. Pat. No. 5,302,833 “Rotational Orientation Sensor For Laser Alignment Control System” by M. R. Mamar, et al.
[0006] U.S. Pat. No. 5,044,844 “Machining Apparatus” by A. E. Backhouse discloses a machine wherein the machining head is mounted on a carriage located on the end of a boom. The boom pivots in a horizontal plane about an axis on spaced circular rails. A laser alignment system senses any inaccuracies in the level of the rails and adjusts the machining head accordingly. However, this system assumes that the cutting head is always properly positioned. This is because the boom and carriage are robust assemblies and only subject to rail inaccuracies. A somewhat similar system is disclosed in U.S. Pat. No. 5,240,359 “Machining Apparatus” also by A. E. Backhouse.
[0007] U.S. Pat. No. 5,768,137 “Laser Aligned Robotic Machining System For Use In Rebuilding Heavy Machinery” by R. J. Polidoro, et al. discloses a positioning system for resurfacing and repairing rails and guideways of large heavy machinery. A monorail assembly incorporating the milling head is assembled parallel to the rail. The straightness of the rail is determined by a laser measurement system. This information is fed to a computer and is used to align the monorail with the rail. The rail can then be machined to bring it back into tolerance. However, this machine requires a complex set up procedure and is only adapted to machine rails. It could not be used to machine molds and the like.
[0008] None of the above machines are capable of being brought to a remote site and used to machine a work-piece that has been previously setup in a fixed position. All of the prior art machines require precise alignment of the work-piece to the machine. In addition, none of the prior art machines automatically monitor the position of the cutting head and insure that it is in the proper position during machining operations; thus compensating for any movement of the machine or work-piece.
[0009] Thus, it is a primary object of the invention to provide a portable machine for performing machining operations.
[0010] It is another primary object of the invention to provide a portable machine for performing machining operations on a work-piece that does not require precise positioning of the machine prior to commencement of machining operations.
[0011] It is a further object of the invention to provide a portable machine for performing machining operations on a work-piece that automatically compensates for any movement, inadvertent or otherwise, of the machine or work-piece being machined.
SUMMARY OF THE INVENTION
[0012] The invention is a machine for performing machining operations on a work-piece. In detail, the invention includes a carriage having a movable robotic arm assembly incorporating a head containing a tool for performing the machining operations on the work-piece. A laser position determination system is included for determining the actual spatial relationship of the carriage and the work-piece and provides a first signal representative thereof. The laser position determination system further determines the spatial relationship of the head to the work-piece during actual machining operations on the work-piece and provides a second signal representative thereof. A computer running computational software provides a third signal to the robotic arm for machining the work-piece based on a predetermined spatial relationship between the carriage and the work-piece. The computer is adapted to receive the first and second signals and the software adjusts the third signal based on the actual spatial relationship between the carriage and the work-piece prior to machining operations and between the head and the work-piece during machining operations.
[0013] In a first embodiment, it is assumed that the work-piece remains in a fixed position, thus it is only the carriage that can move due to vibrations or the like and the robotic arm subject to error in positioning. Thus it is only necessary to initially determine the spatial relationship between the carriage and work-piece and thereafter only monitor the spatial position of the head during machining operations. Therefore, the laser position determination system includes a single laser transceiver assembly and at least one laser target on the carriage, work-piece and head of the robotic arm assembly. The laser transceiver is first used to determine the spatial relationship of the work-piece, then the carriage and then is placed in a tracking mode to track the head during machining operations.
[0014] In the second embodiment, it is assumed that the work-piece may move. For example, the work-piece could be on a conveyor system that passes by the machine. The work-piece could also be stationary, but subject to movements due to vibrations and the like. Preferably, there are three laser transceivers, one to determine the spatial relationship of the work-piece prior and during machining operations, one to determine the spatial relationship of the carriage prior to machining operations and a third to determine the spatial relationship of the head of the robotic arm assembly during machining operations. In this, embodiment, the computer program continuously monitors the spatial relationship of the work-piece during machining operations and adjusts the third signal accordingly.
[0015] The method of increasing the accuracy of a machine for performing machining operations on a work-piece, the machine having a movable head containing a tool for performing the machining operations on the work-piece, the head movable to predetermined positions directed a computer program within a computer, includes the steps of:
[0016] 1. Determining the actual spatial relationship between the carriage and work-piece prior to machining operations and providing a first signal representative thereof;
[0017] 2. Continuously determining the actual spatial relationship between the head and work-piece during the performance of machining operations and providing a second signal indicative of the actual position; and
[0018] 3. Adjusting predetermined spatial relationship of the head during machining operations based on the first and second signals.
[0019] The method of using the second embodiment involves the steps of:
[0020] 1. Continuously determining the actual spatial relationship between the carriage and work-piece and providing a second signal representative thereof;
[0021] 2. Continuously determining the actual spatial relationship between the head and work-piece during the performance of machining operations and providing a third signal indicative of the actual position;
[0022] 3. Continuously determining the actual spatial relationship of the work-piece during machining operations and providing a third signal indicative thereof; and
[0023] 4. Adjusting the spatial relationship of the head based on the difference between the first, second and third signals.
[0024] The first embodiment of the machine can be used to perform machining operations on a stationary work-piece while compensating for inadvertent movement of the carriage or positional errors caused by the robotic arm. In the second embodiment inadvertent movement of the carriage, robotic arm errors, as well as unintentional movement of the work-piece can be compensated for. In fact, this latter embodiment could be used with parts on a movable assembly line, because the work-piece position is continuously monitored.
[0025] The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages thereof, will be better understood from the following description in connection with the accompanying drawings in which the presently preferred embodiments of the invention are illustrated by way of examples. It is to be expressly understood, however, that the drawings are for purposes of illustration and description only and are not intended as a definition of the limits of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] [0026]FIG. 1 is a side view of the machine and work-piece to be machined.
[0027] [0027]FIG. 2 is a perspective view of the machine and work-piece to be machined.
[0028] [0028]FIG. 3 is a view similar to FIG. 1 illustrating the machine actually performing machining operations on the work-piece.
[0029] [0029]FIG. 4A is a first part of a flow chart of process for controlling the machine.
[0030] [0030]FIG. 4B is a second part of the flow chart illustrated in FIG. 4A.
[0031] [0031]FIG. 5 is a top view of a second embodiment of the machine illustrating the machining of a work-piece in a first position along a moving conveyor.
[0032] [0032]FIG. 6 is a view similar to FIG. 5 illustrating the machine with the conveyor having moved the work-piece to a second position.
[0033] [0033]FIG. 7 is a portion of FIG. 4B illustrating a revised In-Situ Processing Step.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] Referring to FIGS. 1 - 4 , a work-piece or part to be machined, indicated by numeral 10 , is shown secured to the floor 12 by a mounting fitting 14 . As illustrated, the work-piece 10 is rigid foam; however, the work-piece could be a ceramic or metal. The top surface 16 includes three tooling holes 18 in a spaced relationship thereon. The subject machine, generally designated by numeral 19 , includes a laser alignment system 20 , which comprises a laser transceiver assembly 22 mounted in proximity to the work-piece 10 , and three laser targets 24 A, 24 B and 24 C mounted in the tooling holes 18 . A typical laser alignment system is fully discussed in U.S. Pat. No. 4,714,339 “Three to Five axis Laser Tracking Systems” b y K. C. Lau, et al., herein incorporated by reference; although other laser alignment systems can be used.
[0035] In detail, the laser transceiver tracking assembly 22 transmits a laser beam, indicated by numeral 26 to the laser targets 24 A-C mounted on the work-piece 10 and is directed back to the tracking assembly. An interferometer interferes the source beam with the beam that has traveled twice between the laser transceiver assembly 22 and targets in order to measure the separation. By measuring the directions of the beams relative to the to targets, the targets can be located in spatial coordinates and additionally the orientation of the targets can be determined. The measurements are fed to a laser-tracking computer (not shown), which is able to calculate the spatial coordinates of the tool 10 . Systems based on this technology are commercially available. It must be noted that while three laser targets are shown, in some applications a single target may be adequate.
[0036] The machine 19 further includes a portable carriage 28 having a robotic arm assembly 30 mounted on top. The carriage 28 includes wheels 32 , stabilizing jacks 34 and a computer 36 . As illustrated the robotic arm has a tool head 38 in which is mounted a cutter 40 . Robotic arms are commercially available from companies such as Fanuc Robotics, Rochester Hills, Mich. The front face 42 of the carriage 28 includes three laser targets 44 A, 44 B and 44 C in a spaced relationship; although in some applications, a single target can be used. While the targets 44 A-C are shown positioned on the front face 42 other positions are possible such as on the top surface 43 . The carriage 28 is wheeled up to the work-piece 10 and locked in place by the jacks 34 . Preferably, the carriage 28 is positioned in a predetermined optimum position in relationship to the work-piece 10 . This optimum position would be the position of carriage as originally set in the machining program in the computer 36 . However, even if the carriage is set with precise hand measurements, they will not generally be precise enough, such that compensation for positional error must be taken into account.
[0037] Thus the alignment system 20 is used to determine the spatial relationship of carriage 28 to the work-piece 10 using the targets 24 A-C and 44 A-C. Again, it should be noted that in some cases a single target 44 A might suffice. The spatial coordinates of the work-piece 10 and carriage 28 are provided to the computer 36 . Since the relationship between the carriage 28 and robotic arm assembly 30 will be known by the computer 36 , the relationship of the robotic arm to the work-piece can be computed. Thus the computer 36 can calculate the actual offsets to the spatial relationship required to compensate for the actual position of the carriage 28 to the work-piece 10 .
[0038] As previously stated, the carriage 10 , even if locked in place by the jacks 34 , may move and the robotic arm assembly 30 may introduce inaccuracies, and the work-piece 10 is not necessarily on a rigid platform, as in the case of a typical milling machine or the like. Therefore, it is possible that such movement, even if extremely small, could cause inaccuracies in the machining operations. Thus a laser target 46 is mounted on the head 38 of the robotic arm assembly 30 . The laser transceiver assembly 22 uses the target 46 to locate the actual spatial relationship of the head 38 during actual machining operations. This information is provided to the computer 36 , which continuously adjusts the position of the head 38 so that it is in the required spatial relationship to the work-piece 10 .
[0039] In FIG. 4 is a flow chart of the machining process. The flow chart is divided into four sections:
[0040] 1. Set up 50 , wherein the work-piece and carriage positions are determined. The carriage 28 is wheeled into position in proximity to the work-piece 10 . Once in position, the jacks 34 are engaged so that all the weight of the carriage 28 is on the jacks. Note, while desirable, the carriage 28 need not be level or in a particular orientation. The laser alignment system 20 is used to determine the position of the work-piece 10 and carriage 28 . The data on the coordinates of both the work-piece and carriage are used to update the computer program within the computer 36 for machining the work-piece.
[0041] 2. Pre-Processing 52 , wherein the computer processes the positional information and up-dates the machining program. The position information is stored in the computer 36 and is used to calculate a coordinate transformation matrix that will be applied to adjust the robotic arm assembly 30 to machine the work-piece 10 . This allows the tool 40 to be moved to any position necessary to perform the machining operations on the work-piece.
[0042] 3. In-Situ Processing 54 , wherein the work-piece is machined with the laser tracker assembly providing head 38 position information to correct for errors. Prior to machining operations, transceiver assembly 22 will focus on the target 46 on the head 38 of the robotic arm assembly 30 and go into a live feedback tracking mode. The robotic arm assembly 30 will follow the preprogrammed computer program that has been modified by the incorporation of actual positions of the carriage 28 and work-piece 10 . However, the transceiver assembly receives real-time head 38 spatial relationship information. If there is a deviation, the computer program calculates a difference or offset matrix and uses it to “real time” re-position the head 38 to the required position. This process is updated several times a second insuring a smooth machining operation.
[0043] 4. Post Processing 56 , wherein the work-piece is inspected. After the machining operation, the robotic arm assembly 30 is used to inspect the work-piece 10 . It will replace the cutter 40 with an inspection target (not shown). The transceiver assembly 22 tracks the inspection targets' position as the now the machined work-piece is probed. In detail, the flow chart is as follows.
[0044] Section 1, Set up 50 involves steps of:
[0045] Step 60 —Set up carriage 28 and alignment system 20 in proximity to the work-piece 10 .
[0046] Step 62 —Determination of positional relationship of work-piece to the robotic arm assembly 30 of the carriage 28 and provides the information to the computer 36 .
[0047] Section 2, Pre Processing 52 involves the steps:
[0048] Step 64 —Store positional information in computer 36 .
[0049] Step 66 —Perform coordinate transformation to generate transformation matrix
[0050] Step 68 —Update machining program using transformation matrix.
[0051] Section 3, In-Situ Processing 54 involves the steps of:
[0052] Step 70 —Transceiver assembley 22 tracks target 46 .
[0053] Step 72 —Machine to preprogrammed path.
[0054] Step 73 —Measure actual position of head
[0055] Step 75 —Determine if head 38 at proper position. Computer program determines deviation between actual head position and desired position. If the head 38 is at the proper position, to Step 76 .
[0056] Step 76 —Determine if machining is complete. If complete then to Step 78 of Post Processing 56 Section. If machining is not complete then Step 80 .
[0057] Step 80 —Generate a delta transformation matrix and calculate offsets. Thereafter return to Step 72
[0058] Section 4, Post Processing 56
[0059] Step 78 —Robotic arm assembly 30 replaces cutter 40 and inserts a spring loaded laser target (not shown)
[0060] Step 82 —Machine work-piece inspected.
[0061] Step 84 —Record measured data
[0062] Step 86 —compare measured data with desired surface contour. If not within tolerance, return to step 80 , if within tolerance then job is complete.
[0063] A second embodiment of the invention is depicted in FIGS. 5 and 6. Here work-pieces 90 A, 90 B and 90 C are shown mounted on a conveyor system 92 and have two slots 94 A and 94 B shown on completed part 90 C, partially machined on work-piece 90 B and in dotted lines on part 90 A. The carriage 28 ′ is identical to carriage 28 except that the laser targets 44 A, 44 B and 44 C are mounted on the top surface 43 . The tool 40 mounted in the head 38 of the robotic arm 30 is shown machining the slot 94 A in the work-piece 90 B. In FIG. 6, the work-piece 90 B, which has moved further down the conveyor system 92 and the machine has machined the slot 94 A and has started to machine slot 94 B. A support column 96 extends up from the floor 12 , which includes a horizontal arm 98 extending over the conveyor system 92 and carriage 28 ′. The arm 98 mounts three laser transceiver assemblies 100 A, for tracking laser targets 44 A- 44 C; 100 B for tracking laser targets 24 A, 24 B and 24 C mounted on the work-piece 90 B; and 100 C for tracking laser target 46 mounted on the head 38 . The spatial relationships of the work-piece 90 B and head 38 can be tracked as the conveyor system 92 moves the work-pieces there along. Note that is not necessary to track the carriage 28 ′ during the machining operations because the head 38 is monitored. Therefore, the laser transceiver 100 C could be used to initially locate the carriage 28 ′ and thereafter used to monitor head 38 position; thus only two laser transceiver assemblies are really necessary.
[0064] Referring to FIG. 7, the process is similar to that disclosed in FIG. 4B except the In-Situ Processing Section, now indicated by numeral 54 ′, includes a “Step 73 A Determination of actual position of work-piece” between “Step 73 —Determine if head is in proper position” and “Step 74 —Is mill at proper position 74 . In Step 73 A, the laser transceiver assembly 100 B tracks the targets 24 A, B and C to determine if the work-piece has moved from its initial position.
[0065] Thus the invention can be used to perform machining operations on a work-piece. In the first embodiment, it can accommodate movement inadvertent movement between the work-piece and carriage. In the second embodiment, the machine can accommodate continuous movement between the carriage and work-piece. Furthermore, while a conveyor system was shown for purposes of illustration, a basically stationary work-piece, subject to small movements, could easily accommodated. Additionally, it should also be noted that while the machining operations discussed were milling, hole drilling or other operations can be performed with the machine.
[0066] While the invention has been described with reference to particular embodiments, it should be understood that the embodiments are merely illustrative, as there are numerous variations and modifications, which may be made by those skilled in the art. Thus, the invention is to be construed as being limited only by the spirit and scope of the appended claims.
Industrial Applicability
[0067] The invention has applicability to the machine tool industry. | A machine for performing machining operations on a work-piece is disclosed that includes a carriage with a robotic arm mounted thereon. The arm includes a movable head containing a tool for performing the machining operations on the work-piece. A laser position determination system is included for determining the actual spatial relationship position the carriage and the work-piece and providing a first signal representative thereof and further determining the spatial relationship of the head to the work-piece during actual machining operations on the work-piece and providing a second signal representative thereof. A computer having a computer program provides a third signal to the robotic arm for machining the work-piece based on a predetermined spatial relationship between the carriage and the work-piece and for receiving the first and second signals and adjusting the third signal based on the actual spatial relationship between the carriage and the work-piece and the head and the work-piece. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to the art of electrolytic formation of coatings on metallic parts. More specifically, it relates to electrolytic formation of a coating on a metallic substrate by cathodic deposition of dissolved metallic ions in the reaction medium (electrolyte) onto the metallic substrate (cathode), or anodic conversion of the metallic substrate (anode) into an adherent ceramic coating (oxide film).
BACKGROUND OF THE INVENTION
[0002] It is well known that many metallic components or parts need a final surface treatment. Such a surface treatment increases functionality and the lifetime of the part by improving one or more properties of the part, such as heat resistance, corrosion protection, wear resistance, hardness, electrical conductivity, lubricity or by simply increasing the cosmetic value.
[0003] One example of a part that is typically surface treated is the head of aluminum pistons used in combustion engines. (As used herein an aluminum component is a component at least partially comprised of aluminum, including aluminum alloys.) Such piston heads are in contact with the combustion zone, and thus exposed to relatively hot gases. The aluminum is subjected to high internal stresses, which may result in deformation or changes in the metallurgical structure, and may negatively influence the functionality and lifetime of the parts. It is well known that formation of an anodic oxide coating (anodizing) reduces the risk of aluminum pistons performing unsatisfactorily. Thus, many aluminum piston heads are anodized.
[0004] There is a drawback to anodizing piston heads. Conventional anodizing with direct current or voltage, increases the surface roughness of the initial aluminum surface by applying an anodic coating. The increase in surface roughness can be as high as 400%, depending on the aluminum alloy and process conditions. The amount of VOC (Volatile Organic Compounds) in the exhaust of a combustion engine is correlated with the surface finish of the anodized aluminum piston: higher surface roughness reduces the efficiency of the combustion, because a greater proportion of organic compounds can be trapped in micro cavities more easily. Therefore, a smooth surface is required, which may not always be provided by anodization.
[0005] A typical prior art power supply for the conversion of metallic aluminum into a ceramic coating (aluminum oxide or alumna) provides direct current, normally between 3 and 4 A/dm2. Typically, a film thickness of 20 to 25 microns is reached after 30 to 40 minutes.
[0006] Convention anodizing includes subjecting the aluminum to an acid electrolyte, typically composed of sulfuric acid or electrolyte mixed with sulfuric and oxalic acid. The anodizing process is generally performed in electrolytes containing 12 to 15% v/v sulfuric acid at relatively low process temperature, such as from −5 to +5 degrees C. Higher concentrations and temperature usually decrease the formation rate significantly. Also, the formation voltage decreases with higher temperature, which adversely affects the compactness and the technical properties of the oxide film.
[0007] Performing anodizing process at (relatively) low temperature and fairly high current density increases the compactness and technical quality of the coating performance (high hardness and wear resistance). The anodization produces a significant amount of heat. Some heat is the result of the exothermic nature of the anodizing of aluminum. However, the majority of the heat is generated by the resistance of the aluminum towards anodizing. Typically, the reaction polarization is high, such as from 15-30 volts, depending upon the composition of the alloying elements and the process conditions. Given typical current densities, from 80% to 95% of the total heat production will be resistive heat.
[0008] The electrolyte is acidic, and thus chemically dissolves the aluminum oxide. Thus, the net formation of the coating (aluminum oxide) depends on the balance between electrolytic conversion of aluminum into aluminum oxide and chemical dissolution of the formed aluminum oxide.
[0009] The rate of chemical dissolution increases with heat. Thus, the total production of heat is a significant factor influencing this balance and helps determines the final quality of the anodic coating. Heat should be dispersed form areas of production toward the bulk solution at a rate that prevents excess heating of the electrolytic near the aluminum part. If the balance between formation and dissolution is not properly struck, and dissolution is favored, the oxide layer may develop holes, exposing the alloy to the electrolyte. This often happens in prior art anodization methods and is known as a “burning phenomena”.
[0010] Heat produced at the aluminum surface is dispersed by air agitation or mechanically stirring of the electrolyte in which the oxidation of aluminum is taking place, in the prior art, to help reach the desired balance.
[0011] Another way of dispersing the heat is by spraying the electrolyte toward the aluminum surface (U.S. Pat. No. 5,534,126 and U.S. Pat. No. 5,032,244). The electrolyte is sprayed toward the aluminum surface at an angle of 90 degrees, moving heat toward the areas of production, and then symmetrically dispersed away from the aluminum surface.
[0012] Another way to disperse heat is to pump the electrolyte over the aluminum substrate (U.S. Pat. No. 5,173,161). The electrolyte is moved parallel to the aluminum surface, moving heat from the lower part of the aluminum substrate over the entire surface before it is finally dispersed away from the aluminum surface.
[0013] A steady state transport mechanism in electrochemical analysis (not anodization) techniques based on wall jet processes can be achieved by either rotating the working electrode, or by directing the flow toward a stationary electrode, at an angle of between 60 and 70 degrees. By angling the jet stream of the reaction medium to 60-70 degrees where steady state conditions are obligatory, electrochemical analysis can be made. Steady state conditions in a jet stream orthogonal to the working electrode is less suitable for wall jet electrochemical analysis. The inventor is not aware of this information having been applied to an electrolytic process.
[0014] The driving force of the charge-transfer reaction taking place at the substrate surface in the process described in U.S. Pat. Nos. 5,032,244, 5,534,126 and 5,173,161, was direct current. The reaction medium was a solution of sulfuric acid or a combination of sulfuric and oxalic acid in U.S. Pat. No. 5,032,244. The electrolyte formulation was 180 g/l sulfuric acid and the process temperature was +5 degrees C. A current density of 50 A/dm2 produced a coating with a thickness of 65 microns in 3 minutes. The microhardness of the obtained coating was between 200 and 300 HV.
[0015] A second process included the addition of 10 g/l oxalic acid at the same current density. A coating having a thickness of more than 60 microns and having a microhardness greater than 400 HV was obtained in 5 minutes.
[0016] After anodizing, the aluminum parts are typically rinsed and dried. Both anodizing, rinsing and drying is made in the same process chamber in all three US patents mentioned above. Some chambers have at least two aluminum parts (see U.S. Pat. No. 5,534,126 or 5,173,161). Others have a single part in each chamber (see U.S. Pat. No. 5,032,244).
[0017] Conventional batch anodizing has used square wave alternation of current or potential. This allows anodizing to be performed at higher current densities compared to anodizing with direct current. The pulse anodizing is characterized by a periodically alternation between a period with high current or voltage, during with the film is formed, and a period with low current or voltage, during which heat is dispersed (U.S. Pat. No. 3,857,766). This technique utilizes the “recovery effect”, after a period of high formation rate (a pulse period), heat is allowed to disperse during the following period with low formation rate (a pause period) and defects in the coating are repaired before the current increases during the next pulse. The relative durations of the higher magnitude and lower magnitude currents determine the relative amount of oxide formation and heat dispersion. One such type of simple pulse pattern may be found in U.S. Pat. No. 3,857,766 or Anodic Oxidation of Al. Utilizing Current Recovery Effect , Yokohama, et al. Plating and Surface Finishing, 1982, 69 No. 7, 62-65.
[0018] U.S. Pat. No. 3,983,014, entitled Anodizing Means And Techniques, issued Sep. 28, 1976 to Newman et al., discloses another type of pulse pattern. The pulse pattern described in Newman has a high positive current portion, followed by a zero current portion, followed by a low negative current portion, followed again by a zero current portion. Each of the pulse portions represent one quarter of the cycle. Thus, the current has a high positive value during the first quarter of the cycle. No current is provided during the next quarter of the cycle. The current has a low negative value during the third quarter cycle. Zero current is provided during the final quarter of the cycle.
[0019] Another prior art pulse pattern is described in U.S. Pat. No. 4,517,059, issued May 14, 1985, to Loch et al. Loch discloses a pulse pattern that is a square wave alternating between a relatively high positive current and a relatively low negative current. The durations of the positive and negative portions of the pulses are controlled used in an attempt to control the anodizing process.
[0020] U.S. Pat. No. 4,414,077, issued Nov. 8, 1983, to Yoshida et al. describes a train of pulses superimposed on a dc current. The pulses are of a plurality opposite to that of the dc current.
[0021] Other prior art methods use a sinusoidal voltage wave, or portions thereof, applied to the voltage buses used for generating the anodizing currents (i.e. potentiostatic pulses). However, such prior art systems do not utilize current pulses for controlling the anodizing process. Examples of such prior art systems may be found in U.S. Pat. No. 4,152,221, entitled Anodizing Method, issued May 1, 1979, to Schaedel; U.S. Pat. No. 4,046,649, entitled Forward-Reverse Pulse Cycling Pulse Anodizing And Electroplating Process issued Sep. 6, 1977, to Elco et al; and U.S. Pat. No. 3,975,254, entitled Forward-Reverse Pulse Cycling Anodizing And Electroplating Process Power Supply, issued Aug. 17, 1976, to Elco et al.
[0022] Each of the aforementioned prior art methods, while utilizing a pulse of some sort, does not provide adequate hardness and thickness while maintaining a low reject rate. Moreover, such prior art systems are relatively slow and take a relatively long period of time to complete the anodizing process.
[0023] The time of each period is typically ranges from 1 to 100 seconds in the prior art, depending on the aluminum substrate. The prior art does not describe a correlation between a pulse pattern (pulse current, pulse duration, pause current and pause duration) and the result of the anodizing process. (See Yokogama, above). Thus, the optimal pulse conditions have been determined by trial and error. The coating quality of pulse anodized aluminum is generally superior to anodic coatings produce with direct current according to the prior art (Surface Treatment With Pulse Current, Dr. Jean Rasmussen, December 1994.)
[0024] An anodizing method and apparatus that reduces processing time with high formation potentials and minimal handling to obtain coatings of desirable quality and consistency is desirable. The process and apparatus will preferably lessen production costs and have a closed loop process design that reduces the impact of the electrolyte on internal and external environments. The process will preferably remove heat from near the component being anodized.
SUMMARY OF THE PRESENT INVENTION
[0025] According to one aspect of the invention a method of anodizing an aluminum component begins by placing an aluminum component in an electrolyte solution. Then a number of pulses are applied to the solution and component. Each pulse is formed by a pattern including a portion having a first magnitude, a portion having a second magnitude, and a portion having a third magnitude. The third magnitude is less than the first and second magnitudes, and all three magnitudes are of the same polarity.
[0026] According to one embodiment the third magnitude is substantially less than the first and second magnitudes. Another embodiment provides that the third magnitude is substantially zero.
[0027] A different embodiment has the pulse pattern include alternations between the first and second magnitudes, and following the alternations, the third magnitude. Another variation provides the pulse pattern having the first magnitude portion, followed by the second magnitude portion, followed by the first magnitude portion, and then followed by the third magnitude portion. Yet another embodiment includes the pulse pattern having the first magnitude portion, followed by the third magnitude portion, followed by the third magnitude portion.
[0028] A different embodiment includes the pulse pattern having the first, second and third magnitudes substantially constant. Another alternative provides that at least one of the first, second and third magnitudes is not constant.
[0029] Another embodiment has the duration of at least one of the second and third portions different from the duration of the first magnitude portion. An alternative includes applying the portions in the sequence of the first magnitude portion followed by the third magnitude portion, followed by the second magnitude portion. Another variation includes a pulse pattern having four or more different magnitudes.
[0030] An additional step of applying at least one additional pulse, having a different pulse pattern, is included in an alternative embodiment. The transition between magnitudes is fast in one embodiment, and slow in another.
[0031] According to a second aspect of the invention an apparatus for anodizing an aluminum component includes a reaction chamber, which has at least a portion of the component placed therein. The reaction chamber can hold a reaction fluid or electrolyte. A transport chamber is in fluid communication with the reaction chamber. The fluid enters the reaction chamber from the transport chamber through a plurality of inlets directed toward the component. The fluid follows a return path, such that the fluid returns from the reaction chamber to the transport chamber.
[0032] A fluid reservoir is provided in one alternative. The reservoir is in fluid communication with the transport chamber, and the return path includes the fluid reservoir. A pump between the fluid reservoir and the transport chamber pumps fluid to the transport chamber, thereby forcing the fluid through the inlets to the component in a plurality of jets directed at the component in a variation.
[0033] The reaction chamber has a substantially circular cross section, as does the transport chamber in various alternatives. The transport chamber may be substantially concentric with the reaction chamber.
[0034] In one embodiment the fluid is directed toward the component at an angle of between 15 and 90 degrees. In another embodiment the fluid is directed toward the component at an angle of between 60 and 70 degrees.
[0035] The reaction chamber is substantially vertical, and has at least one side wall and at least one bottom wall in another embodiment. The inlets are in the side wall such that the fluid enters the reaction chamber substantially horizontally. The reaction chamber has at least one outlet beneath the inlets. The outlet may be in the bottom wall.
[0036] The side wall is a common wall with the transport chamber in another embodiment. Also, the reaction chamber has a top with a removable portion, in an alternative. The top is adapted for mounting the component therein, and a portion of the component extends into the reaction chamber and a portion extends above the reaction chamber. The inlets are at the same height as at least a portion of the component in one alternative.
[0037] The component is held in a mounted position mechanically or pneumatically in various alternatives.
[0038] The inlet is the cathode, and the component is the anode, whereby current flows between the cathode and the anode in another embodiment.
[0039] Other principal features and advantages of the invention will become apparent to those skilled in the art upon review of the following drawings, the detailed description and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] FIG. 1 is a block diagram of a general method implementing the present invention;
[0041] FIG. 2 is a schematic sectional view of process container implementing the present invention;
[0042] FIG. 3 is a detailed schematic sectional view a working electrode mounted in a mounting fixture, in accordance with the preferred embodiment;
[0043] FIG. 4 is a detailed schematic sectional view a working electrode mounted in a mounting fixture, in accordance with the preferred embodiment;
[0044] FIG. 5 is a graph showing an current pulse pattern in accordance with the present invention;
[0045] FIG. 6 is a graph showing formation rate vs. current density for two temperatures;
[0046] FIG. 7 is a graph showing surface roughness vs. average current density for two and three level pulse patterns;
[0047] FIG. 8 is a graph showing formation rate vs. average current density for two prior art processes;
[0048] FIG. 9 is a graph showing surface roughness vs. average current density for two prior art processes; and
[0049] FIG. 10 is a top sectional view of an outer wall of a reaction chamber, with inlets in accordance with the preferred embodiment.
[0050] Before explaining at least one embodiment of the invention in detail it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. Like reference numerals are used to indicate like components.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0051] While the present invention will be illustrated with reference to a particular process for anodizing and a particular fixture for holding an aluminum part and directing the electrolyte thereto, it should be understood at the outset that other process parameters, such as alternative material or solutions, or other apparatus may be employed to implement the invention.
[0052] The process and apparatus described herein is generally shown by a block diagram of FIG. 1 . Anodizing occurs in a process container 100 (described in more detail later). A working electrode 102 (i.e. the part to be anodized) is placed in a reaction container 104 , which is part of container 100 . After anodizing part 102 is moved to a rinsing tank 110 , where the working electrode is rinsed with D.I. water, pumped from a rinse reservoir 112 by a pressure pump 114 into a rinse chamber 116 , through a set of spray nozzles 118 . The rinse water leaves the rinse chamber 116 through a rinse outlet 119 and returns to the rinse reservoir 112 . Working electrode or part 102 is mechanically held in position during the rinse. After rinsing, working electrode 102 is transferred to a drying container 120 , where it is dried with hot air from a heater 122 , which is pumped into the drying container 120 through several drying inlets 124 .
[0053] Alternatives include performing multiple steps (such as anodizing and rinsing) in a single container or providing a station (following drying container 120 , e.g.) that scan the component as a quality control measure. The scanning may be automatically performed using known techniques such as neural network analysis.
[0054] Referring now to FIG. 2 , a schematic of a section of process container 100 and related components, is shown to comprise an outer circular transport chamber 201 and inner reaction container 104 . The reaction medium (electrolytic solution) is transported from a medium reservoir 202 , located below process container 100 , by a pressure pump 203 into transportation chamber 201 through several inlet channels 205 . Alternatives include other shaped chambers, as well as the inlets and outlets being in different locations.
[0055] Transportation channel 201 and reaction container 104 are separated by an inner wall consisting of a lower portion 206 , made of an inert material, and an upper electrochemically active portion 207 , which is the counter electrode. Alternatively, the entire wall may be the electrode. The reaction medium enters reaction container 104 through a set of reaction inlets 210 through counter electrode 207 . The reaction medium enters reaction container 104 angled relative to the surface of the part, aluminum substrate, or working electrode 102 . The angle to the part is within the range of 15 to 90 degrees, preferably 60 to 70 degrees.
[0056] The reaction medium leaves reaction container 104 through a reaction outlet 212 and returns to medium reservoir 202 . The inner wall (comprised of portions 206 and 207 ), and an outer wall 213 are fixed to a bottom wall 214 . Walls 206 , 213 and 214 are comprised of an inert material, such as polypropylene. Reaction container 104 is closed by a moveable top lid made of an inert material such as polypropylene, which includes a cover lid 219 and a mounting fixture 220 , and in which working electrode 102 is placed. Mounting fixture 220 is exchangeable and specially designed for the particular parts or working electrode 102 which is being anodized.
[0057] The upper portion of working electrode 102 is exposed to air, enhancing the dispersion of heat accumulated in working electrode 102 during processing. Working electrode 102 connected to a typical rectifier (controlled as discussed below) by an electrical contact 230 , which is pressed against working electrode 102 after mounting.
[0058] Selective formation of coatings on working electrode 102 is ensured by a top mask consisting of a inert top jig 225 holding a rubber mask 226 , which abuts the lower face of working electrode 102 . The top mask is mounted to mounting fixture 220 by a number of adjustable fasteners 228 , which are comprised of an inert material.
[0059] Working electrode 102 mounted in mounting fixture 220 is shown in more detail in FIG. 3 . Working electrode 102 is pressed against top mask, particularly rubber mask 226 , and held in position by a rubber O-ring 301 . Rubber o-ring 301 is compressed mechanically toward the top mask by a mounting ring 303 . Working electrode 102 is removed by releasing the pressure on rubber O-ring 301 , by moving mounting O-ring 302 away from the top mask.
[0060] FIG. 4 shows a pneumatic mounting design, in which O-ring 301 is pressed against working electrode 102 by pumping compressed air into a pressure tank 401 through several air inlets 402 . The pressure on working electrode 102 is released by opening a pressure valve 403 , so that working electrode 102 can be removed.
[0061] The reaction medium is sprayed toward the metallic substrate through holes in the counter electrode in a manner that reaction products (heat) are carried away from the metallic substrate (working electrode). FIG. 10 shows a top sectional view of reaction chamber 104 . A plurality of inlets 1001 are shown, and are angled between 60 and 70 degrees. The mounting and masking device allows selective formation of coatings on the metallic substrate at high speed by applying a specially designed modulation of direct current or voltage characterized by periodically alternation from at least one period of high reaction potential and periods of no, low or negative reaction potential.
[0062] The apparatus discussed thus far has several advantageous (although not necessary) features. First, process container provides for flow of the reaction medium from a bulk solution below the container through the reaction chamber and back into the reservoir. Second, the reaction medium moves toward the working electrode at an angle so that heat may be quickly dissipated away from the working electrode. Third, the mounting, while easy to use and economical, allows for heat to be dissipated away from the top of the working electrode, which is exposed to air. Fourth, the reaction medium is sprayed toward the metallic substrate through holes in the counter electrode in a manner that reaction products, in addition to heat, are carried away from the metallic substrate (working electrode).
[0063] In addition to the apparatus described above, the inventive method using a reaction medium comprised of a solution of sulfuric acid or mixtures of sulfuric acid and suitable organic acids like oxalic acid. The concentration of sulfuric acid ranges from 1% v/v to 50% v/v, but preferably from 106% v/v to 20% v/v. The concentration range of one or more organic acids, added to the sulfuric acid electrolyte, is from 1% v/v to 50% v/v, but preferable from 10% v/v to 15% v/v. Working electrode 102 is an aluminum piston (aluminum 1295 or 1275, e.g.) acting as anode (connected positively to the rectifier) and the counter electrode 201 is aluminum 6062 (or titanium) acting as the cathode (connected negatively to the rectifier). The component may be made of other materials.
[0064] The electrolyte is stored and chilled to an appropriate process temperature ranging from −10 degrees C. to +40 degrees C., preferable between +10 degrees C. and +25 degrees C., in a reservoir below the reaction container. The electrolyte is pumped up into the reaction chamber at a flow rate from 4 LPM (Liter Per Minute) to 100 LPM, but preferable between 30 LPM and 50 LPM and returned to the reservoir.
[0065] The flow of direction of electrolyte is toward the aluminum surface so heat is transported away from the areas of heat production. Steady state heat dispersion is established by spraying the reaction medium at an angle from 15 to 90 degrees, but preferably between 60 and 70 degrees relative to the aluminum substrate surface.
[0066] The electrolyte is transported up to the reaction site in an outer circular inlet chamber and through the counter electrode toward the aluminum piston. The counter electrode contains from one to 50, but preferable from 8 to 12 transport inlets to the reaction chamber and is made of e.g. aluminum AA 6062 , or other materials (such as titanium e.g). The counter electrode is connected to the rectifier and acts as cathode (negative).
[0067] The jet stream of electrolyte, angled toward the piston surface, establishes a steady state dispersion of heat away from the areas of production. Furthermore, dispersion of heat is enhanced gravitationally, when the electrolyte enters the lower part of the reaction chamber. The electrolyte leaves the reaction chamber at the outlet in the bottom of the reaction chamber and returns to the reservoir container below the reaction chamber.
[0068] The piston is mounted in the mounting fixture and is pressed toward the top mask in order to ensure masking of the piston crown. The piston is held in position by pressure from the rubber O-ring. The pressure on the O-ring is either mechanically as shown in FIG. 3 or pneumatic as in FIG. 4 . The piston is then connected to the rectifier as anode (positive).
[0069] After anodizing, the electrical contact to the piston is removed and pressure is removed from the O-ring relaxes. The piston is then transferred to the rinsing container after which it is dried with hot air.
[0070] The design of the pulse current pattern of the preferred embodiment is a periodically alternation between perio s of very high current density (preferably more than 50 A/dm2), high current density (preferably more than 4 A/dm2), and low current density (preferably less than 4 A/dm2). The duration of each individual current density ranges from 0.12 seconds to 40 seconds, but preferable from 1 second to 5 seconds. The final number of repeated pulse cycles is determined by the specified nominal thickness of the oxide layer.
[0071] The duration of the period between a pulse, i.e., the transient time necessary for new stabilized conditions at the bottom of the pores for the new current conditions, is related to the difference between pulse and pause current density. Increased difference between the two current densities reduces the time necessary for 100% utilization of the recovery effect. Also, raising the temperature of the anodizing solution increases the transient time for the recovery effect. The transient time for the recovery effects during batch anodizing for cast aluminum containing high amounts of silicon (7% w/w) is between 10 and 25 seconds, depending in the process conditions.
[0072] A formation rate in the range of 25 microns per minute, nearly twice as fast as conventional direct current batch anodizing, requires a large difference in the pulse current densities, especially if the process temperature is above the typically range of conventional anodizing (>+5 degrees C.). Then inventor has learned that a pulse pattern having periodic alternation between three current densities in combination with increased process temperature (between +10 degrees C. and +15 degrees C.) and concentration of sulfuric acid (17% v/v) results in a coating thickness of 25 microns in less that one minute. Table 2 below shows various experimental data. The temperature and the amount of sulfuric acid in the anodizing electrolyte are generally higher than the maximum values in prior art anodizing.
[0073] A pulse modulated current pattern (one cycle) in accordance with the present invention is shown in FIG. 5 . Each cycle includes alternations between a medium current density 501 and a high current density 502 , followed by a time of low (or zero) current density 503 . This pattern is repeated several times until the final thickness of the anodic coating is reached.
[0074] The average current of the pulse patterns determines the formation rate. A comparison of formation rate, surface roughness and microhardness of aluminum piston batch processed under direct current conditions and with pulse modulated current is shown in Table 1.
TABLE 1 Direct Current Pulse Temperature (C.) 0 15 15 Sulfuric Acid (% v/v) 13 17 17 Current Density (A/dm 2 ) 24 25 25 Formation rate (μm/min) Fail Fail 22.4 Surface roughness (μm) N/A N/A 2.2 Microhardness (HV 0.025 ) N/A N/A 217
[0075] The inventor has learned, as shown in Table 1, that batch anodization of aluminum pistons is possible with high current density (>>3 A/dm2) if the recovery effect is utilized, as in the pulse current method of the present invention. The formation of heat during direct current anodizing disturbs the balance between formation and dissolution of the oxide film, resulting in a breakdown of the coating (the burning phenomena). The low microhardness for the pulse-anodized piston is a result of high heat production and insufficient removal of heat in a batch process.
[0076] FIG. 6 is a graph showing that formulation rate depends on the average current density for various pulse patterns (in accordance with the pattern of FIG. 5 ), and that the formation rate is substantially independent of process temperatures between +7 degrees C. and +13 degrees C.
[0077] Surface roughness increases with process time and current density for conventional batch anodizing using direct current. The surface roughness, measured as R a , increases with average current density for pulse designs containing alteration between a pulse period and a pause (a two level pulse pattern). However, the surface roughness is independent of the average current density for pulse designs containing two pulses and a pause period (a three level pulse patter such as that of FIG. 5 ). This is shown in the graph of FIG. 7 , which plots surface roughness vs. current density for two and three level pulses. The surface roughness for three level pulse patterns changed from 1.6 microns prior to anodizing to 2.2 microns after anodizing, which is approximately a 38% increase. The pulse designs of the experiments are shown in table 2 below, and generally include a pulse pattern having two relatively high current portions (33 A/dm2 and (33 A/dm2 e.g.) and a third portion have a substantially lower current portion (less than one-half, and preferably about one-tenth, e.g.). The electrolyte contained 17% v/v sulfuric.
TABLE 2 1) 10 s at 20 A/dm 2 , 5 s at 2 A/dm 2 , repeated 3 times at 15° C. 2) 10 s at 26 A/dm 2 , 5 s at 2 A/dm 2 , repeated 3 times at 15° C. 3) 10 s at 33 A/dm 2 , 5 s at 2 A/dm 2 , repeated 3 times at 15° C. 4) 5 s at 33 A/dm 2 , 2 s at 53 A/dm 2 , 3 s at 33 A/dm 2 , 5 s at 2 A/dm 2 , repeated 3 times at 15° C. 5) 2 s at 33 A/dm 2 , 2 s at 53 A/dm 2 , 1 s at 33 A/dm 2 , 2 s at 53 A/dm 2 , 3 s at 33 A/dm 2 , 5 s at 2 A/dm 2 , repeated 3 times at 7° C. 6) 2 s at 33 A/dm 2 , 2 s at 53 A/dm 2 , 1 s at 33 A/dm 2 , 2 s at 53 A/dm 2 , 1 s at 33 A/dm 2 , 2 s at 53 A/dm 2 , 5 s at 2 A/dm 2 , repeated 3 times at 7° C. 7) 2 s at 33 A/dm 2 , 2 s at 59 A/dm 2 , 1 s at 33 A/dm 2 , 2 s at 59 A/dm 2 , 1 s at 33 A/dm 2 , 2 s at 59 A/dm 2 , 5 s at 2 A/dm 2 , repeated 3 times at 7° C.
[0078] Alternatives include fewer repetitions, varying the order of the different magnitudes, having one pulse pattern different from the other pulse patterns, and providing zero current in the low current portion.
[0079] The formation rate and surface roughness of direct current anodized pistons according to process principles in U.S. Pat. Nos. 5,534,126 and 5,032,244, where the electrolyte is sprayed orthogonal toward the piston head, is shown in FIGS. 8 and 9 . The roughness and formation rate provided by these prior art processes is not as good as the roughness and formation rate provided by the present invention. The prior art formation rate increases with current density in sulfuric acid electrolytes. Also, there is a slightly increased formation rate by addition of oxalic acid. The surface roughness increases with current density and by addition of oxalic acid. Anodizing at 20 A/dm2 in a sulfuric acid electrolyte containing 10 g/l oxalic acid produces in 90 seconds 24 μm oxide coating in 90 seconds. The surface roughness is 2.64 μm. Raising the current density to 30 A/dm2, the formation rate increases and 23 μm coating is produced in 1 minute, but the surface roughness increases to 3.01 μm. For comparison, the surface roughness of pistons after conventional direct current anodizing at 0 degrees C. and at 3 A/dm2, is 2.66 microns.
[0080] Numerous modifications may be made to the present invention which still fall within the intended scope hereof. Thus, it should be apparent that there has been provided in accordance with the present invention a method and apparatus for anodizing parts that provides a fixtures that disperses heat from the part, and provides an anodizing current in a pulsed pattern such that the anodization is faster and/or has desirable properties that fully satisfies the objectives and advantages set forth above. Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. | A method and apparatus of anodizing a component, preferably aluminum, is disclosed. The component is placed in an electrolyte solution. A number of pulses are applied to the solution and component. Each pulse is formed by a pattern including having three magnitudes. The third magnitude is less, preferably substantially less, than the first and second magnitudes, and all three magnitudes are of the same polarity. The pulse pattern may include alternations between the first and second magnitudes, and following the alternations, the third magnitude. Other patterns may be provided. The solution is in a reaction chamber, along with at least a portion of the component. The fluid enters the reaction chamber from a transport chamber through a plurality of inlets directed toward the component, preferably at an angle of between 60 and 70 degrees. The inlet is preferably the cathode, and the component is the anode, whereby current flows between the cathode and the anode in another embodiment. The inlets are in a side wall such that the fluid enters the reaction chamber substantially horizontally. The reaction chamber has at least one outlet beneath the inlets. The outlet may be in a bottom wall. The fluid follows a return path, such that the fluid returns from the reaction chamber to the transport chamber. The component is held in a mounted position mechanically or pneumatically in various alternatives. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of Provisional Application Ser. No. 61/001,438, filed Nov. 1, 2007, the entire content of which is hereby incorporated by reference.
BACKGROUND
[0002] A variety of heat exchangers exist in which a number of tubes are connected to and in fluid communication with a collection tank for introducing and/or removing fluid from the flat tubes. In many cases, the applications of such heat exchangers result in high pressure and thermal stresses, such as in locations at and adjacent to the connections of the flat tubes to the collection tank. Also, it is desirable for such collection tanks and the connections of the flat tubes thereto to withstand significant pressure without excessive deformation or damage—despite the desire to construct collection tanks from increasingly thinner and lighter materials. Particularly in cases in which the collection tanks are constructed of multiple parts (e.g., a header plate and a structure defining the remainder of the collection tank), this capability should extend to the interface between the collection tank parts.
[0003] Further design issues for many heat exchangers relate to the use of gaskets between heat exchanger components, such as tube-to-header plate gaskets, gaskets located between header plates and other collection tank components, and the like. Such gaskets must perform their hydraulic or pneumatic sealing functions while being exposed in some applications to high pressures and/or temperatures, material expansion and contraction, and other challenges. Reliable gaskets and gasket retention continue to be elusive in many applications.
[0004] Accordingly, it will be appreciated that heat exchangers having collection tanks and collection tank-to-flat tube joints adapted to withstand thermal and/or pressure stresses and cycling are welcome additions to the industry, as are reliable heat exchanger gaskets and gasket retention designs, and heat exchangers that are relatively light weight and that can be produced more efficiently and at a lower cost.
SUMMARY
[0005] Some embodiments of the present invention provide a header for a collection tank of a heat exchanger. The header can provide an increased level of strength to the heat exchanger and to connections between the header and tubes connected thereto. The header can have a convex shape configured to reduce thermal mechanical stresses at tube-to-header joints, and to reduce pressure stresses.
[0006] In some embodiments, the header of the collection tank is manufactured from plastic, and is curved about a longitudinal axis of the collection tank, thereby presenting a generally convex shape toward the tubes connected thereto, and a generally concave shape toward an interior of the collection tank. The tubes can have any cross-section shape desired. However, unique advantages can be achieved by the use of flat tubes (i.e., tubes having opposing substantially broad flat sides joined by opposing narrow sides) connected to the header.
[0007] By virtue of a curved header as described above, plastic headers can withstand internal collection tank pressures that could otherwise generate significant header deformation. Under pressure loading of the curved plastic header described above, there is a considerably reduced degree of header deformation. In some embodiments, such deformation can even be eliminated. As a result, the mechanical load experienced by connections between the header and tubes fastened thereto is considerably reduced.
[0008] Additionally, by virtue of the curved plastic header as described above, it is possible in some embodiments to achieve increased strength of the header and of the connections between the header and tubes. Since the strength of the header and the tube-to-header connections often decreases from the periphery of the header toward the center of the header, the above-described header curvature in a central region of the header significantly increases the strength of the header in the central region. As a result of the increased strength, it is possible to achieve weight and cost savings by reduction of the thickness of the material from which the header and/or tubes is constructed. The increased mechanical strength also increases the service life of a collection tank and heat exchanger having such a header. Such advantages do not necessarily require any additional expenditure with regard to the header and collection tank material, the number of header and collection tank components, and the individual production stages of the header and collection tank. Also, reproducible and permanently sealed connections between the header and individual tubes are possible using the curved header described above and relatively low production tolerances.
[0009] Other aspects of the present invention relate to manners in which a header can be connected to the rest of a collection tank while retaining a gasket or other seal in position with respect to such parts, manners in which to provide a seal at the interfaces between the tubes and header of a heat exchanger, and manners in which the collection tank and portions of the collection tank and header interface can be reinforced to increase the pressure capacity of the collection tank and/or to enable the use of thinner and different collection tank materials.
[0010] In some embodiments, a heat exchanger is provided, and comprises a plurality of tubes each having opposing broad and substantially flat sides joined by two opposing narrow sides; a header having a plurality of apertures each dimensioned to receive a corresponding tube of the plurality of tubes; a collection tank coupled to the header and having an internal chamber in fluid communication with the plurality of tubes; a gasket located between the collection tank and the header; and at least one reinforcement extending across the internal chamber.
[0011] Some embodiments of the present invention provide a heat exchanger, comprising a plurality of tubes each having opposing broad and substantially flat sides joined by two opposing narrow sides; a plastic collection tank having an internal chamber in fluid communication with the plurality of tubes; a metal header coupled to the plastic collection tank and having a plurality of apertures each dimensioned to receive a corresponding tube of the plurality of tubes, the metal header elongated in a longitudinal direction and curved about a longitudinal axis of the metal header to present a concave shape to the internal chamber and a convex shape away from the internal chamber; a gasket at least partially separating the metal header from the plastic collection tank and sealing a gap between the metal header and the plastic collection tank; and a reinforcement extending across the internal chamber and at least partially retaining the gasket in position between the metal header and the plastic collection tank.
[0012] In some embodiments, a heat exchanger is provided, and comprises a plurality of tubes each having opposing broad and substantially flat sides joined by two opposing narrow sides; a collection tank having an internal chamber in fluid communication with the plurality of tubes; a header coupled to the collection tank and having a plurality of apertures each dimensioned to receive a corresponding tube of the plurality of tubes, the header elongated in a longitudinal direction and curved about a longitudinal axis of the header to present a concave shape to the internal chamber and a convex shape away from the internal chamber; and a gasket received on a tube of the plurality of tubes and curved about the longitudinal axis of the header.
[0013] Still other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view of a collection tank having a tank reinforcement member according to an embodiment of the present invention.
[0015] FIG. 2 is an exploded view of the collection tank shown in FIG. 1 .
[0016] FIG. 3 is a detail view of the tank reinforcement member shown in FIGS. 1 and 2 .
[0017] FIG. 4 is a detail view of the gasket shown in FIGS. 2 and 3 .
[0018] FIG. 5A is a cross-sectional view of the collection tank shown in FIG. 1 , taken along line 5 A- 5 A of FIG. 1 .
[0019] FIG. 5B is a perspective assembled view of the collection tank and the tank reinforcement member shown in FIGS. 1-3 and 5 A.
[0020] FIG. 6A is a schematic cross-sectional view of a collection tank, reinforcement member, and header according to an embodiment of the present invention.
[0021] FIG. 6B is a perspective view of a collection tank assembly according to an embodiment of the present invention.
[0022] FIG. 6C is an exploded perspective view of the collection tank assembly shown in FIG. 6B .
[0023] FIG. 6D is a detail view of the collection tank assembly shown in FIGS. 6B and 6C .
[0024] FIG. 6E is a perspective view of a part of the collection tank assembly shown in FIGS. 6B-6D .
[0025] FIG. 6F is a cross-sectional perspective view of part of the collection tank assembly shown in FIGS. 6B-6E .
[0026] FIG. 6G is a cross-sectional perspective view of part of a heat exchanger according to another embodiment of the present invention.
[0027] FIG. 6H is a cross-sectional perspective view of part of a heat exchanger according to another embodiment of the present invention.
[0028] FIG. 6I is a cross-sectional perspective view of part of a heat exchanger according to another embodiment of the present invention.
[0029] FIG. 7 is a top perspective view of a header according to an embodiment of the present invention.
[0030] FIG. 8 is a bottom perspective view of the header shown in FIG. 7 .
[0031] FIG. 9 is a perspective view of part of a heat exchanger according to another embodiment of the present invention.
[0032] FIG. 10 is a cross-sectional perspective view of the heat exchanger shown in FIG. 9 , taken along line 10 - 10 of FIG. 9 .
[0033] FIG. 11 is a cross-sectional perspective view of a heat exchanger according to another embodiment of the present invention.
[0034] FIG. 12 is a perspective view of a grommet shown in FIG. 9 .
[0035] FIG. 13 is an end view of the grommet shown in FIG. 11 .
DETAILED DESCRIPTION
[0036] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
[0037] FIGS. 1-5B illustrate a collection tank assembly header 110 adapted for a collection tank of a heat exchanger 124 . The heat exchanger 124 is suitable for any application in which heat exchange takes place with fluid passing through the collection tank. Such applications exist in vehicle systems, such as those used in conjunction with internal combustion engines. In some applications for example, the heat exchanger 124 can function as a cooler, as a condenser, or as an evaporator. Also, in some applications, the heat exchanger 124 can be connected to exchange heat in a refrigerant circuit.
[0038] The collection tank assembly 110 illustrated in FIGS. 1-5B includes a collection tank 100 (only part of which is shown in FIGS. 1-5B ), a tank reinforcement member 104 , and a gasket 108 . The illustrated collection tank 100 is constructed of a first portion 100 A at least partially defining an enclosure through which fluid flows, and another portion (not shown in FIGS. 1-5B ) called a header. The header connects with the first portion 100 A of the collection tank 100 to substantially enclose an internal chamber of the collection tank 100 . An example of a header 204 that can be used in conjunction with the first collection tank portion 100 A is shown in FIGS. 7 and 8 , and will be described in greater detail below.
[0039] In some embodiments, the first portion 100 A of the collection tank 100 is made of aluminum, steel, iron, or other metal, whereas the header (e.g., header 104 ) is made of plastic. Although this material combination provides unique performance results (including a thin-walled but strong first portion 100 A able to withstand significant pressures while permitting the use of a less expensive and/or easy to manufacture plastic header), other materials and material combinations are possible. For example, in other embodiments, both the first portion 100 A and the header are made of plastic. As another example, in other embodiments, both the first portion 100 A and the header are made of metal. Alternatively, in still other embodiments, the first portion 100 A is made of plastic, while the header is made of metal.
[0040] The first portion 100 A of the collection tank 100 can be secured to the header (e.g., header 204 shown in FIGS. 7 and 8 ) in a number of different manners, some of which provide a degree of resistance to fluid leakage under internal collection tank pressures. To this end, peripheral edges of the first portion 100 A can abut peripheral edges of the header, such as the planar peripheral edges of the header 204 shown in FIGS. 7 and 8 . The first portion 100 A and the header can be secured in these and other locations by welding, soldering, brazing, and the like.
[0041] To prevent leakage of fluid out of the collection tank 100 , a gasket 108 is located between the first portion 100 A of the collection tank 100 and the header. The illustrated gasket 108 extends about the periphery of the first portion 100 A and the header, and can be made of rubber, plastic, or any other material suitable for forming a seal.
[0042] As mentioned above, the collection tank assembly 110 shown in FIG. 105B also includes a tank reinforcement member 104 to help retain the gasket 108 in a position with respect to the first portion 100 A of the collection tank 100 and the header in which fluid is prevented from exiting the collection tank 100 during operation of the heat exchanger 124 . The reinforcement member 104 shown in FIG. 7 is plastic, and can be manufactured by injection molding. Alternatively, the reinforcement member can be made of any other suitable material (including without limitation aluminum, steel, iron, and other metals, composite materials, and the like), and can be manufactured in any other suitable manner (including without limitation casting, stamping, pressing, deep drawing, extruding, machining, and the like).
[0043] The tank reinforcement member 104 illustrated in FIGS. 1-3 , 5 A, and 5 B includes interlock apertures 112 configured to receive the gasket 108 . The apertures 112 can be dimensioned to receive and retain portions of the gasket 108 by an interference fit. The illustrated tank reinforcement member 104 further includes cross-webs 116 , which provide further support to the tank reinforcement member 104 . The cross-webs 116 enable the collection tank assembly 110 to withstand greater internal pressures, and can enable the collection tank assembly 110 to withstand loads experienced by a header being crimped to the collection tank 100 .
[0044] The illustrated gasket 108 includes gasket cross-webs 120 configured to provide additional support to the gasket 108 . In some embodiments, the cross-webs 120 extend across the internal chamber of the collection tank 100 . In some embodiments, the gasket 108 further includes positioning shoulders 124 which guide placement of the gasket 108 within the interlock slots 112 (e.g., insuring that the cross-webs 120 are positioned properly within the collection tank 100 upon installation of the gasket 108 and/or maintaining a peripheral portion of the gasket 108 in proper position within a seat 111 defined by the tank reinforcement member 104 ).
[0045] In operation, the tank reinforcement member 104 can be placed in the collection tank 100 immediately after the collection tank 100 is molded. Alternatively, the tank reinforcement member 104 can be placed in the collection tank 100 any time prior to usage. The collection tank 100 can be shaped and dimensioned to receive the tank reinforcement member 104 by a clearance fit, snap fit, press fit, or in any other mating manner. For example, the tank reinforcement member 104 illustrated in FIGS. 1-3 , 5 A, and 5 B mate with the collection tank 100 via multiple projection and aperture sets. This mating relationship can enable the projections and apertures to slide with respect to one another until reaching a limit of movement (e.g., a bottom of each aperture), thereby defining a positive stop for accurate placement of the tank reinforcement member 104 with respect to the collection tank 100 . Accurate placement of the tank reinforcement member 104 can allow for proper gasket placement and compression without contact or interference with the heat exchanger header. A locking feature or a heat staking operation can be used to provide further support and retain the tank reinforcement member 104 within the collection tank 100 .
[0046] By virtue of the relationship between the gasket 108 and the tank reinforcement member 104 described above with regard to some embodiments of the present invention, the gasket 108 can be installed on the tank reinforcement member 104 (e.g., by pressing cross-webs 116 or other portions of the gasket 108 into apertures 112 in the tank reinforcement member 104 ), and the tank reinforcement member 104 and gasket 108 can be moved or otherwise manipulated by a user or machine for installation in the collection tank 100 . In those embodiments in which there is an interference fit of the gasket 108 with the tank reinforcement member 104 (e.g., within the apertures 112 described above), this movement or manipulation can even place the tank reinforcement member and gasket assembly in an inverted position.
[0047] In light of the relationship between the gasket 108 and the tank reinforcement member 104 described above, assembly of a resulting heat exchanger can be simplified and improved. Also, the gasket 108 can be retained in proper position with respect to the collection tank 100 and header throughout the life of the heat exchanger.
[0048] Although a separate tank reinforcement member 104 as described above is desirable in many applications, it should be noted that the tank reinforcement member 104 and any of the gasket retention features described above can instead be integral with the collection tank 100 (e.g., molded as part of the collection tank 100 ) in other embodiments.
[0049] FIGS. 6A-6I illustrate collection tank assemblies 210 with tank reinforcement members 203 according to other embodiments of the present invention. Like the illustrated embodiment of FIGS. 1-5B above, the collection tank assemblies 210 illustrated in FIGS. 6A-6I each have a collection tank 200 comprising a first collection tank portion 200 A and a header 204 , a tank reinforcement member 203 , and a gasket 208 . The illustrated collection tank assemblies 210 are well-suited, for example, to radiator and charge air cooler applications utilizing brazed or grommeted tube-to-header joints. As also provided in the embodiment of FIGS. 1-5B (but not shown therein), the header 204 can be attached to flat tubes received within slot-shaped openings 216 in the header 204 . The tubes can be fastened to and within the header 204 in a pressure-tight manner by soldering, welding, adhesive or cohesive bonding material, or in any other suitable manner.
[0050] With reference to the embodiments of FIGS. 6A-6F and 6 H- 6 I, headers 204 illustrated therein have a generally curved central portion 220 and a peripheral shoulder 222 extending laterally therefrom. The curved central portion 220 presents a convex shape to the tubes and a concave shape to the interior of the collection tank 200 . The design of the illustrated header 204 provides an increase in strength of the header 204 and provides an increase in strength of the connections between the header 204 and tubes (not shown) by stiffening the header 204 near the tube-to-header joints. Also, the curved central portion 220 reduces pressure stresses in both the header gasket well 221 (i.e., the location in which the gasket 208 is retained) and in the tube noses. Therefore, it is possible to reduce the cross-sectional thickness of the individual components of the collection tank assembly 210 to achieve weight and cost savings. As a result of the increase in the mechanical strength of the header 204 (and more generally, of the collection tank assembly 210 ), the service life of the collection tank assembly 210 and of a correspondingly configured heat exchanger is increased without any additional material expenditures, heat exchanger components, or individual production steps.
[0051] Also by virtue of the curved shape of the central header portion 220 described above and illustrated in FIGS. 6A-6F , and 6 H- 8 , deformation of the header 204 is anticipated. It will be appreciated that under moderate collection tank pressures, deformation of a header 204 having no curvature is likely. However, due to the curved central portion 220 of the header 204 , when the curved central portion 220 of the header 204 is under pressure loading, the header 204 experiences a considerably reduced degree of deformation. As a result, mechanical load on the connections between inserted tubes and the header are reduced, and bending stress upon the header 204 (e.g., due to internal pressures of the collection tank 200 ) are converted into tensile stresses, thereby providing increased strength of the header 204 and the header-to-tube connections. Since the strength of the header 204 and/or of the header-to-tube connections can decrease toward the center of the header 204 in many embodiments, the curvature of the central portion 220 of the header 204 increases the strength of the header 204 in the center of the header 204 .
[0052] With continued reference to the illustrated header embodiments of FIGS. 6A-6F and 6 H- 8 , the header 204 also has a substantially flat peripheral shoulder 222 which can extend about the entire periphery of the curved central portion 220 . This shoulder 222 can at least partially define a gasket well 221 (mentioned above) in which a gasket 208 between the header 204 and first collection tank portion 200 A is retained in any of the manners described above.
[0053] In some embodiments, the header 204 of the collection tank 200 is manufactured from plastic, and is curved about a longitudinal axis of the collection tank 200 , thereby presenting a generally convex shape toward the tubes connected thereto, and a generally concave shape toward an interior of the collection tank 200 . In other embodiments, other header materials can instead be used as desired. Also, any of the material combinations described above in connection with the embodiment of FIGS. 1-5B are applicable in connection with FIGS. 6A-6I .
[0054] The tubes for connection to the headers 204 shown in FIGS. 6A-6I can have any cross-section shape desired. However, unique advantages can be achieved by the use of flat tubes (i.e., tubes having opposing substantially broad flat sides joined by opposing narrow sides) connected to the header 204 .
[0055] The collection tank assemblies 210 illustrated in FIGS. 6A-6F and 6 H- 8 each have a tank reinforcement member 203 . The tank reinforcement member 203 can be substantially flat as shown in FIGS. 6A-6F and 6 H- 8 , and can have any number of reinforcing webs 212 extending across the interior of the collection tank 200 in longitudinal or lateral directions (thereby increasing the strength of the collection tank 200 ) without obstructing or significantly obstructing flow through the collection tank 200 to or from the tubes connected to the collection tank 200 . The tank reinforcement member 203 can be connected to the collection tank 200 in any of the manners described above. For example, in some embodiments, slots in the tank reinforcement member 203 accept collection tank features with a snap-fit, press-fit, or other mating engagement when the collection tank 200 is installed upon a core of a heat exchanger. As shown in FIGS. 6A-6F and 6 H- 6 I, in some embodiments the tank reinforcement member 203 is received within and/or lies upon the header 204 . In some embodiments, the tank reinforcement member 203 lies within and/or upon the shoulder 222 of the header 204 , and can extend beneath, below, or beside the gasket 208 . The tank reinforcement member 203 can increase the material thickness of the collection tank assembly 210 (e.g., doubling the thickness of the gasket well area 221 , for example), such as in an area of the collection tank 200 adjacent the gasket 208 . Also, the tank reinforcement member 203 can strengthen the collection tank 200 in various ways, such as by extending the capability of tank-to-header crimp joints in high-pressure applications.
[0056] In some embodiments, the tank reinforcement member 203 can be assembled with the header 204 prior to or during core assembly. The tank reinforcement member 203 can be connected to the header 204 , for example, in any manner desired, including without limitation by brazing or welding, by Tox® rivets (Tox Pressotechnik GmbH & Co. KG), or in any other manner desired. For example, a complete braze joint between the header 204 and tank reinforcement member 203 can be used in those embodiments in which the tank reinforcement member 203 at least partially defines a sealing surface for the gasket 208 .
[0057] Some embodiments of the present invention utilize additional collection tank strengthening elements alone or in conjunction with any of those described above (e.g., the tank reinforcing members 104 , 203 ). FIGS. 6 A and 6 G- 6 I provide examples of such strengthening elements. With reference first to FIG. 6A , the collection tank 200 can be provided with one or more reinforcements 250 extending from one or more walls of the collection tank 200 to a position engaged with a tank reinforcement member 203 as shown schematically in FIG. 6A . These reinforcements 250 can have any shape desired, such as elongated fingers as shown in FIGS. 6A , 6 H, and 6 I, wider plates as shown schematically in FIG. 6G (in which case the reinforcements 250 can compartmentalize the interior of the collection tank 200 , in some embodiments), and the like. Also, these reinforcements 250 can be integral with the collection tank 200 or can be separate elements permanently or releasably attached thereto in any manner. The reinforcements 250 can be positioned and oriented to engage the tank reinforcement member 203 so that flexure or other movement of the collection tank 200 can be limited. The reinforcements 250 can also be movable with respect to the tank reinforcement member 203 (e.g., by a sliding fit, one or more lost motion connections, and the like), thereby enabling force to be transmitted through the reinforcements 250 in one direction, but with no or limited ability for force transmission in an opposite or other direction. For example, it may be desirable for the reinforcements 250 to prevent outward bulging or flexure of a collection tank wall, while still permitting inward movement of the same wall, or to permit movement of one or more portions of the collection tank 200 (e.g., header flexure) responsive to varying heat exchanger tube expansion and contraction during operation of the heat exchanger. Although only two collection tank reinforcements 250 are shown in particular positions in FIGS. 6A and 6G , and a particular number of such reinforcements are visible in FIGS. 6H and 6I , it will be appreciated that any number of such reinforcements 250 extending across the interior of the collection tank 200 can be used, in many cases without disruption to flow within the collection tank 200 .
[0058] FIGS. 9-13 illustrate heat exchangers utilizing various features according to some embodiments of the present invention. With reference to FIGS. 9 , 10 , 12 , and 13 , an option for any of the curved header heat exchangers described above is to utilize curved grommets 228 . Such grommets 228 can be made from rubber, EPDM, or any other material suitable for providing a fluid-tight seal, and could be installed within the tube apertures of the header 204 or upon the ends of tubes being inserted within the tube apertures of the header 204 . With particular reference to FIGS. 12 and 13 , the illustrated grommet 228 has an opening 232 similar to the openings 216 in the header 204 , and is also configured to receive a flat tube 224 . The grommets 228 in the illustrated embodiment are shaped to provide an interference fit with the exterior of the flat tubes in order to prevent fluid leakage through the header-to-tube joints, while still allowing tubes experiencing thermal expansion and contraction to move as necessary. Regardless of the cause of tube movement, such grommets 228 can enable the tubes to move independently of one another and of the header 204 (by sliding within the grommets 228 , in some cases). The grommet design can be used for plastic tank radiators, charge-air-coolers, all-aluminum tank and header designs, and a number of other heat exchanger applications.
[0059] The embodiments described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention. | Various embodiments of the present invention provide a heat exchanger having a collection tank having an internal chamber, and a header connected to the collection tank and receiving a number of flat tubes through apertures in the header. In some embodiments, a reinforcing member received within the collection tank and/or the header functions to reinforce the header and/or the collection tank in applications where these elements are subject to internal pressures that would otherwise deform the header and/or collection tank to an unacceptable extent. Also, some heat exchanger embodiments utilized a curved gasket on each flat tube to match the shape of the flat tubes and a curved header. Also, another gasket can be located between a metal or plastic collection tank and a plastic or metal header, respectively, to prevent leakage therebetween. | 5 |
This application is the national phase under 35 U.S.C. § 371 of PCT International Application No. PCT/IS01/00023 which has an International filing date of Dec. 19, 2001, which designated the United States of America.
FIELD OF THE INVENTION
The present invention relates to a method to measure the shape of a foot by means of comparing the foot with a reference foot and by means of selecting out a reference area where there is a deviation from the foot and the reference foot. The outcome of this is a much more inexpensive and faster way to built orthopaedic shoes.
DESCRIPTION OF THE PRIOR ART
One way to measure a foot is by means of electro-optical scanner, which is capable of accurately determining the foot sizing data. From the data a precise foot wear last can be made by using computer automated design mechanism.
A simpler method to make an orthopaedic shoe is by means of a footwear system wherein a sample shoe is tried on by a wearer and the one providing the best fit is chosen. Thereafter, a stock shoe is re-formed with a moulding apparatus to provide a shoe last which is a copy of the stock shoe. The shoe last is what a shoemaker needs to make an orthopaedic shoe.
What characterises these methods is how time consuming the process is from the fitting to the making of the shoes and how expensive it is. Furthermore, there is a difference between the foot when the person is walking and the foot when the persons is standing still. The scanning method can have the disadvantage that this difference is not taken into account when the orthopaedic shoe is made.
The problem in relation to the present invention differs from the above mentioned inventions that it is a time saving method. A reference shoe can be produced in about 20-30 seconds compared to 15 minutes using current state of the art methods, which involve a vacuum presser and 2-3 plastic sheets. Furthermore, the new plastic shoe costs only a fraction of the cost of the old ones.
GENERAL DESCRIPTION OF THE INVENTION
It is an object of the present invention to provide a method and a system that will allow for a cheaper and faster way to make orthopaedic shoes. Further, the object of the present invention is to present a new way for ordering orthopaedic shoes through a communication channel such as the Internet.
According to the first aspect, the invention relates to a method for measuring the shape of a foot, said method comprising the steps of:
compare the shape of the foot with the shape of a reference foot by:
a) fitting a reference shoe to the foot, b) locating an area wherein the foot and the reference shoe do not coincide, c) selecting a filler unit for the located area and attaching the filler unit to a corresponding area of a shoe last, d) reforming the shape of the reference shoe by fitting the reference shoe to the shoe last.
If the reference shoe does still not fit to the foot the procedure a)-d) are repeated until the reference shoe and the foot fit together. Comparing the shape of the foot with the shape of a reference foot preferably comprises fitting the foot to be measured to a reference shoe of the same size by means of fitting the bare foot to the reference shoe. The reference shoe could be available in at least one width so the most likely width would be chosen before starting the fitting procedure and preferably made of resilient material. One way to locate the area where the reference shoe and the foot do not coincide is to inspect where the colour difference of the skin of the foot due to increased pressure from the reference shoe to the foot changes colour, i.e. returns to white. This calls for transparent material of the reference shoe.
In order to locate the area where changes in the reference shoe have to be made in order to fit it to the foot, is to provide the reference shoe with a measuring system. In one embodiment the measuring system is in the form of longitudinal and latitude line wherein the longitudinal lines are marked with for example numbers and the latitude lines with letters. The areas may therefore be transferred to the shoe last, which would be provided with the same measuring system.
After detecting the area where changes from the reference shoe compared to the foot are needed, appropriate filler unit that corresponds to the deviation between the foot and the reference shoe has to be chosen. Preferably these filler units are provided with different sizes and shapes and may be identified by means of numbers or letters or both, wherein the number of areas within the reference shoe is based on information regarding where deviations from a predetermined reference foot generally occur. The filler units may be made of plaster, plastic or any other kind of material. Besides detecting the deviation from the reference shoe, height differences between two legs may be evened out by integrating an insole which corresponds to the height difference between the legs without changing the thickness of the bottom. This makes the height difference invisible.
After selecting a filler unit/units that are likely to correspond to the deviation between the foot and the reference foot, they are attached to a shoe last, wherein the shoe last is provided with the same measuring system as the reference shoe. This enables the attaching of the filler units at the exact same area as where the deviation between the foot and the reference shoe was detected. The attaching of the filler units to the shoe last may be done by means of trammeling them to the shoe last, wherein the shoe last may be made of plaster, plastic or other material. By putting the shoe last with the filler unit/units into the reference shoe, the reference shoe may be reformed to the shape of the last with the filler units attached to it. Preferably the reforming is accomplished by means of heating the shoe last until the material of the reference shoe reforms. After the reforming of the reference shoe, it is fitted again to the foot and the process be repeated, if further changes are needed. If however the reforming fits to the foot, the information regarding the filler units with the numbering regarding the size and shape and the location could be sent to a shoemaker.
A further object of the invention is a method of making shoes fitted to a specific person, said method comprising:
receiving information regarding:
a seize and width of a reference shoe, a number, type and the coordinate of filler units, a height, shape and the type of the insole, and a shoe type and the material and the colour of the material to be used,
wherein based on the received information a orthopaedic shoe is made where information regarding the seize, width, type of insole, number of filler units, type of filler units and the location of the filler units are obtained at the fitting procedure.
The customer may in addition to that choose the type of shoe, the material and the colour by himself. The customer may also receive the information obtained from the fitting and make the order by himself for example through the Internet, wherein the receiver of the information would be provided with the shoe last and the filler units of the same type.
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the invention will now be described in details with reference to the drawing in which:
FIG. 1 shows a Layout Diagram of how the invention,
FIG. 2 shows a reference shoe 1 and the measuring system,
FIG. 3 shows an example of filler units that are used to detect the deviation from the reference foot,
FIG. 4 shows where the filler units are attached to a shoe last and wherein a reference shoe of the same size and width as shown in FIG. 1 is reformed in accordance with the filler units,
FIG. 5 shows an example of how the reforming is made by beans of fitting the shoe last with filler units to the reference shoe, and
FIG. 6 shows an example of how the registration of the filler-unit coordinates on the reference shoe could be made by means of using a computer with a software.
The functionality's of the method in FIG. 1 may be grouped into several parts, whereby the first part is where a reference shoe is fitted to a foot 1 in for example a shoe store, where a sales person fits a reference shoe to the foot of a customer. The fitting could preferably be performed by means of fitting a bare foot to the reference shoe of the same size as the foot. In order to make the fitting more convenient the reference shoe should be made of resilient material such as plastic material. The deviation from the foot 2 from the reference shoe may be located by means of detecting where the foot constricts to the reference foot. This can be achieved by means of detecting where the colour of the barefoot changes when it is both in a rest position and also when it moves. The determination would also be based on where the customer experiences pain. In order to locate where the foot constricts to the reference foot, the reference shoe has to be provided with a measuring system.
After determining where changes on the reference shoe have to be made, appropriate filler units that correspond to the deviation between the foot and the reference shoe have to be chosen 3 . This choice can be based on the experience of the sales person. Preferably the filler units are provided with different sizes and shapes and may be identified by means of numbers or letters or both.
After choosing the appropriate filler units, they are attached to a shoe last of the same size and width as the reference shoe and the reforming procedure of the reference shoe begins. One way of attaching the filler units to the shoe last can be done by means of trammeling them to the shoe last, that is if the shoe last is made of material such as plaster or plastic. The shoe last could also be made of metals and therefore the attaching of the filler units would be made in another way such as by means of gluing them to the shoe last or by means of screwing them to the shoe last. In order to attach the filler units to the exact same as in the reference shoe, the shoe last has to be provided with a similar measuring system as the reference shoe. After attaching the filler units to the shoe last, the reforming procedure may be started 4 . The reforming may be done by means of moulding, wherein the shoe last with the filler units attached to it is fitted to the reference shoe and then heated until the reference shoe has reformed so the shape of the filler units is added to the shape of the reference shoe. If the shoe last would be made of metal the heating could be controlled by means of heating the shoe last until the reference shoe has been reformed.
After the reforming of the reference shoe the customer tries on the new reformed reference shoe again 5 . If the reference shoe is still not properly customised the process from 1 - 4 has to repeated again 6 . If however the reference shoe is customised to the foot of the customer 7 , an order can be sent to a shoemaker. The information could comprise the size and the width of the reference shoe and also the number and the type of the filler units with their location on the reference shoe. Furthermore, height differences between to customers legs may be evened out by means of integrating an insole to the shoe with a height that corresponds to the height difference between the legs without changing the thickness of the bottom. This would make the height difference invisible.
FIG. 2 shows the reference shoe 9 with an example of a measuring system, wherein the measuring system is in the form of longitudinal and latitudinal lines and wherein the longitudinal lines are marked with numbers 10 and the latitudinal lines with letters 11 . The purpose of such coordinate system is to locate where a reforming from the reference shoe is needed, i.e. to locate the filler units, and to transform the changes that are needed to the shoe last, which should be provided with a similar measuring system. As already mentioned, the material of the reference shoe is preferably made of transparent material. This is in order to be able to visually locate the area where the foot and the reference shoe do no coincide, wherein the location is based on colour differences on the bear foot as mentioned before. Furthermore, the reference shoe should be made of deformable material such as plastic material.
FIG. 3 shows an example of filler units of a different sizes but located within the same reference area, where the smaller one 12 indicates a small deviation from the reference shoe and the larger one 13 larger deviation. Each reference area can be provided with plurality of filler units with a different shape and size.
FIG. 4 shows an example where the filler units 14 - 16 are attached to a shoe last with the same size and width as the reference shoe. The figure shows also where the height difference between the legs has been integrated by means of using an insole instead of increasing the thickness of the bottom 17 .
FIG. 5 shows an example of the reforming procedure wherein the shoe last 18 with the attached filler units 19 is fitted to a reference shoe 20 . For an exact registration of the filler-unit-coordinates on the reference shoe, a computer with a software may be used as shown in FIG. 6 , wherein the resolution of the coordinate system would be much higher than the one on the reference shoe. By means of showing the exact same shoe on the screen, i.e. the same size and width, the exact coordinates could be chosen by means of approaching the reference area on the computer monitor where the foot and the reference shoe do not coincide as close as possible and select that point. By selecting it, the result could be registered in the computer system with the type of filler unit.
The registration could also be performed by means of registering manually directly from the reference shoe. This is however more inaccurate due to the lower resolution. Example of this is where the reference area of the foot and the reference shoe do not lie between a longitudinal line 5 and a latitudinal line 7 . The resolution of the measuring system on the shoe would not be enable an exact location of that point wherein the computer software would provide more exact result.
From the number, type and the coordinates of the filler units along with the shoe type, material of the shoe and the type of bottom that the customer wishes an order may be sent to a shoemaker or shoe factory that even specialises in making orthopaedic shoes. The order could be carried out through a communication channel such as the Internet or by means of faxing the order to the shoe factory. The factory would be provided with similar shoe lasts and filler units, and by means of having this information, orthopaedic shoes in accordance with the customers wishes could be made. | The present invention relates to a method for measuring the shape of a foot by means of comparing the shape of the foot with the shape of the reference foot. This is done by fitting a reference shoe to the foot, locating the area wherein the foot and the reference shoe do not coincide, selecting appropriate filler units for the located area and attaching the filler unit to a corresponding area of a shoe last and reforming the shape of the reference shoe by fitting the reference shoe to the shoe last. This is repeated until the reference shoe and the foot fit together. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method and an apparatus for performing a conversion process on the basis of a colorimetry result of a color patch output by an output device.
[0003] 2. Related Background Art
[0004] Conventionally, a color masking method of obtaining an output color space by performing a matrix calculation on an input color space, and a method of obtaining an output color space from an input color space using a lookup table (LUT) have been widely used as methods of correcting color to improve a color reproduction effect in a color reproduction process on a printer.
[0005] However, since the output characteristic of a color printer includes strong nonlinearity, a global method such as the color masking method, that is, a method in which the entire output color space is affected by a change of a matrix value, has difficulty in adequately approximating the characteristic of a color printer in all color ranges. Also in the method using the LUT, table values are often determined according to the masking method, so that the same difficulty in color reproducibility is found.
SUMMARY OF THE INVENTION
[0006] An object of the present invention is to precisely approximate the nonlinear output characteristic of an output device and thus enable color reproduction with high precision.
[0007] In order to achieve the above object, the present invention is characterized as follows.
[0008] That is, according to the invention, there is provided an image processing method for converting a device-independent color space into a color space dependent on an output device, comprising the steps of:
[0009] inputting a colorimetry value of a color patch output by the output device and represented in the device-independent color space;
[0010] extracting a colorimetry value close to a conversion target value represented in the device-independent color space, from the input colorimetry value; and
[0011] performing, according to a distance between the input colorimetry value and the extracted colorimetry value in the device-independent color space, a weighting process for a color value corresponding to the extracted colorimetry value and represented in the color space dependent on the output device so as to obtain a color value corresponding to the input colorimetry value and represented in the color space dependent on the output device.
[0012] Further, according to the invention, there is provided an image processing method for mapping input data outside a color reproduction range of an output device onto the color reproduction range of the output device, based on a colorimetry result of a color patch output by the output device, comprising:
[0013] extracting from the input data the plural colorimetry results close to a position where a vertical line is down onto the color reproduction range of the output device, based on the colorimetry result of the color patch positioned on the outside edge of the color reproduction range; and
[0014] obtaining a mapping result for the input data from the plural extracted colorimetry results.
[0015] The above and other objects, features and advantages of the invention will become more apparent by reference to the following detailed description of the invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] [0016]FIG. 1 is a diagram showing the configuration of the first embodiment of the present invention;
[0017] [0017]FIG. 2 is a diagram showing an example of an input color→Lab LUT 102 ;
[0018] [0018]FIG. 3 is a diagram showing an example of a color patch 109 ;
[0019] [0019]FIG. 4 is a diagram showing colorimetry values obtained in a colorimetry process by a color patch colorimetry unit 110 ;
[0020] [0020]FIG. 5 is a diagram showing the process of selecting Lab values (Lab→DeviceRGB conversion unit 106 );
[0021] [0021]FIG. 6 is a diagram showing a weight function depending on a distance;
[0022] [0022]FIG. 7 is a diagram showing a sample point function;
[0023] [0023]FIG. 8 is a diagram showing the configuration according to the second embodiment of the present invention; and
[0024] [0024]FIG. 9 is a diagram showing the configuration according to the third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] {First Embodiment}
[0026] The first embodiment of the present invention will be described below by referring to the attached drawings.
[0027] [0027]FIG. 1 shows the contents of the process according to the present embodiment. An input signal is a color space signal dependent on a device, and can be, for example, an RGB signal read by a scanner A, a CMYK signal to be output to a printer B. When the present embodiment is applied to a copying machine, the signal can be the RGB signal read by the scanner. When a proof is checked, the signal can be the CMYK signal to be output to the target printer.
[0028] The above input signals are input to an input color Lab conversion unit 101 , and converted into signals in a Lab space which is a color space independent of a device. According to the present embodiment, the conversion is realized by an LUT conversion using the input color Lab LUT 102 . At this time, a table used in the conversion is to be set appropriate in an input color space. For example, when an RGB color space dependent on the scanner A is an input side, a three-dimensional input/three-dimensional output RGB→Lab conversion table corresponding to an RGB signal value and a Lab value dependent on the scanner A is set as an LUT. Similarly, when a CMYK color space dependent on the printer B is an input side, a four-dimensional input/three-dimensional output CMYK→Lab conversion table corresponding to a CMYK signal value and a Lab value dependent on the printer B is set as an LUT. FIG. 2 shows an example of an LUT. The example shown in FIG. 2 shows the correspondence between an RGB value having 8 bits for each of the R, G, and B and a Lab value, and only the Lab value is stored as an actual LUT.
[0029] In the input color→Lab conversion unit 101 , the address on the table is computed from the input signal to retrieve the Lab value from the LUT, interpolation calculation is performed using the retrieved Lab value, and a Lab value corresponding to the input signal is obtained.
[0030] The Lab signal obtained by the input color→Lab conversion unit 101 is then input to a Lab→DeviceRGB conversion unit 104 , and is converted into a signal in a DeviceRGB space which is a space dependent on a printer 107 by using DeviceRGB→Lab LUT 105 .
[0031] When an input color space is an RGB space, the color range is larger than the color reproduction range of the printer in most cases. Therefore, a color space compression conversion unit (or a color gamut mapping unit) 103 first performs a mapping process in the color reproduction range, and then inputs a Lab signal into the Lab→DeviceRGB conversion unit 104 .
[0032] A signal converted by the Lab→DeviceRGB conversion unit 104 for the DeviceRGB space is also converted by the Lab→DeviceRGB conversion unit 106 for a CMYK color space dependent on the printer 107 , and is then transferred to the printer 107 . Various well-known methods can be used for the RGB→CMYK conversion, and thus any of the methods can be arbitrarily used.
[0033] According to the present embodiment, the following equations are used for conversion.
K =min(1.0− R , 1.0 −G, 1.0 −B )
C= (1.0 −R )− K
M= (1.0 −G )− K
Y= (1.0 −B )− K
[0034] (Lab→DeviceRGB Conversion Process)
[0035] Described below in detail are the Lab DeviceRGB conversion unit 104 and the DeviceRGB Lab LUT 105 .
[0036] In the Lab→DeviceRGB conversion unit 104 , a conversion process is performed based on the correspondence between the DeviceRGB signal value stored in a color patch generation unit 108 and the Lab colorimetry value obtained by the color patch colorimetry unit 110 .
[0037] (Generation of DeviceRGB→Lab LUT 105 )
[0038] First, the color patch generation unit 108 generates a color patch signal indicating a color patch image as shown in FIG. 3. The color patch signal is transferred to the printer 107 through a process path only passing the Lab→DeviceRGB conversion unit 106 , and the printer 107 generates a color patch image 109 .
[0039] The color patch signal is generated such that the DeviceRGB space can be equally divided. In FIG. 3, an RGB space having 8 bits each for R, G, and B is equally divided into 9×9×9 unit, and 729 patches are obtained. In this example, the color space dependent on the printer 107 is a CMYK color space. However, since it is considered that an RGB space can be converted into a CMYK color space according to the conversion rule from the RGB space, the RGB space is considered to be a color space dependent on the printer 107 .
[0040] Second, the color patch colorimetry unit 110 performs a colorimetry process on the obtained color patch image 109 , and a Lab colorimetry value is obtained for each patch. FIG. 4 shows an example of the obtained Lab colorimetry value.
[0041] In the operation, the RGB value generated by the color patch generation unit 108 and the Lab colorimetry value obtained by the color patch colorimetry unit 110 can be obtained. Therefore, a DeviceRGB→Lab LUT for storing the correspondence between the DeviceRGB and the Lab colorimetry value on the points on which the DeviceRGB space is equally divided can be obtained.
[0042] (Lab→DeviceRGB Conversion)
[0043] A Lab→deviceRGB conversion is performed using the generated DeviceRGB→Lab LUT, but a problem occurs in the conversion. That is, when an LUT computation is performed, conventional interpolation calculation such as the interpolation on a cube, the interpolation on a tetrahedron, etc. is performed. However, the above interpolation calculation can only be performed on a table value when the table input side has a uniform grid. Nevertheless, the DeviceRGB→Lab LUT obtained in the above process does not have a uniform table value for an input Lab value. Therefore, the interpolation calculation cannot be normally performed using a Lab value as an input value.
[0044] Therefore, according to the present embodiment, a Lab→deviceRGB conversion is performed in the following procedure.
[0045] First, the distance (equal to the color difference obtained by a Lab color difference equation) between the Lab value in the DeviceRGB→Lab LUT and the input Lab signal is computed and stored. The obtained distance is expressed by d.
[0046] Second, N entries are selected from the DeviceRGB→Lab LUT in order from the shortest distance d for the input Lab value.
[0047] At this time, the Lab values are expressed as follows in order from the shortest distance.
[0048] DeviceRGB 1 →Lab 1 d 1
[0049] DeviceRGB 2 →Lab 2 d 2
[0050] DeviceRGB 3 →Lab 3 d 3
[0051] [0051]FIG. 5 shows the process of selecting Lab 1 , Lab 2 , . . . .
[0052] Third, the DeviceRGB value for an input Lab value is computed as follows.
RGB=ΣRGBi×f ( di )
i=N
f ( x )=1/(1+ x ^ 4)
[0053] In this case, f(x) is a function having the curve as shown in FIG. 6. That is, the interpolation calculation is performed with a larger weight assigned to an RGB value having a shorter distance in the Lab space.
[0054] The number N of the table values in the interpolation calculation can be constant (e.g., 8) in the Lab space.
[0055] However, in the method of the DeviceRGB→CMYK conversion unit, as shown in FIG. 4, the colorimetry values concentrate on a low brightness L* area. Therefore, a problem can occur when N is a constant. In this area, when N is too small, the distance between the input Lab value and the Lab value of the sample point is too short. Accordingly, the interpolation calculation is performed on a small number of sample points using a large weight. As a result, the problems such as a gradation jump in the DeviceRGB space, a bad white balance in a low brightness range, etc. occur.
[0056] Therefore, when the interpolation calculation is performed by changing the number of samples depending on the value of the L of the input Lab value as shown in FIG. 7, the effect of solving the above problems can work. Furthermore, in a high brightness range, the number of samples in the interpolation calculation can be limited, thereby suppressing unclear color. In the function N(L) shown in FIG. 7, the ¼ exponent function is shown as an example with the value of 128 assigned to L=0, and the value of 4 assigned to L=100.
[0057] (Color Space Compression)
[0058] Described below is the color space compression method used by the color space compression conversion unit 103 . There are various methods of color space compression. For example, a color space compression process is performed in a uniform color space as disclosed by Japanese Patent Application Laid-Open No. 8-130655.
[0059] Another example is a method of setting a color space compression conversion condition using a Lab colorimetry value obtained by the color patch colorimetry unit 110 .
[0060] In this color space compression method, a predetermined number (e.g., 8) of Lab values are selected from the DeviceRGB→Lab LUT such that the distance d between the input color outside the color reproduction range and the Lab value of the point of the vertical line down onto the color reproduction range from the input color is short, and that the Lab value is positioned on the outside edge of the color reproduction range. The data of the position of the outside edge of the color reproduction range is the data of the position on the 6 planes of a cube forming a DeviceRGB space. That is, the data of the position of the outside edge of the color reproduction range can be detected in advance based on the RGB value generated by the color patch generation unit 108 .
[0061] As in the above method of obtaining the DeviceRGB for the input Lab value, the interpolating process is performed using a predetermined number of Lab values weighted by the distance d, and a conversion Lab value in the color reproduction range corresponding to the input color outside the color reproduction range is obtained.
[0062] In this color space compression method, an input color outside the color reproduction range can be converted into a color near the outside edge of the color reproduction range having a Lab value of a color close to an input color. That is, a color outside the color reproduction range can be successfully converted into a clear color.
[0063] {Second Embodiment}
[0064] [0064]FIG. 8 shows the configuration of the second embodiment, that is, a modification of the first embodiment, of the present invention. According to the present embodiment, unlike the first embodiment, the conversion from a device independent color space to a printer-dependent color space is performed in the LUT process as in the conversion from an input color to a device independent color space.
[0065] After an input color→Lab conversion unit 801 and an input color→Lab LUT 802 perform the same processes as the input color→Lab conversion unit 101 and the input color→Lab LUT 102 according to the first embodiment, a Lab→CMYK conversion unit 803 performs an LUT conversion using a Lab→CMYK LUT 804 . The CMYK signal processed in the Lab→CMYK conversion is transmitted to a printer 805 and output. The Lab→CMYK LUT 804 is created as follows. A DeviceRGB color patch image is converted into a DeviceCMYK by a DeviceRGB→CMYK conversion unit 807 , and is output on the printer 807 . An output color patch 808 is processed by a color patch colorimetry unit 809 , and an LUT is created by a Lab→CMYK LUT creation unit 810 based on the obtained colorimetry value and the RGB value generated by the color patch generation unit 806 .
[0066] The process of the Lab→CMYK LUT creation unit 810 can be performed by performing the color space compression process according to the first embodiment, the Lab→DeviceRGB conversion process, and the DeviceRGB→CMYK conversion on the grid value of the Lab input into the LUT.
[0067] For example, if the Lab value is processed as an eight-bit signal, then the grid of the Lab is configured with the value of L ranging from 0 to 255, and with the value of a, b ranging from −128 to 127 in 16 units. When the above processes are performed on each grid value, a Lab→CMYK LUT can be created.
[0068] With the above configuration, the conversion performed in the first embodiment from the Lab color space to the CMYK color space can be performed using the LUT, thereby efficiently performing the computation.
[0069] {Third Embodiment}
[0070] According to the present embodiment, the configuration used in the case in which an sRGB color space which has become a standard color space on the Internet is used as an input color space is described. The correspondence between the sRGB color space and the XYZ color space is defined, and the sRGB color space can be considered a device independent color space. Therefore, if the sRGB color value is converted into an XYZ value and a Lab value, and the conversion is performed from the Lab value to the printer color space as described above, the signal in the sRGB color space can be reproduced on a printer.
[0071] [0071]FIG. 9 shows the configuration according to the present embodiment. The input sRGB signal is converted into a CMYK value in the LUT conversion process using an sRGB→CMYK LUT 902 by an sRGB→CMYK conversion unit 901 , transmitted to a printer 903 , and output. The sRGB→CMYK LUT 902 is created by a sRGB→CMYK generation unit 908 based on the colorimetry value obtained by performing the colorimetry process on a color patch 906 by a color patch colorimetry unit 907 and the RGB value generated by a color patch generation unit 904 .
[0072] An sRGB→CMYK LUT is created as follows. Assume that an input sRGB signal is processed as an eight-bit signal, and sRGB grids are configured as 17×17×17 grids. After performing operations of converting sRGB→XYZ and XYZ→Lab by a definition equation, the above Lab→DeviceRGB conversion process and DeviceRGB→CMYK conversion process are performed on each grid value, thereby obtaining an sRGB→CMYK LUT.
[0073] {Modification}
[0074] In the above embodiments, a Lab is used as a color space independent of a device, but other spaces such as XYZ, Luv, etc. can also be used.
[0075] Furthermore, a printer is used as an output device, but other output devices such as a printing device, etc. can also be used. Similarly, a color signal to be transferred to a printer unit is not limited to the YMCK, but other color signals can be used.
[0076] In the above embodiments, the number of patches is 729, but other numbers can also be used.
[0077] While the number N of the table values for use in the interpolation calculation is set based on the brightness L as shown in FIG. 4, it may be set three-dimensionally in consideration of a and b addition to the brightness L.
[0078] Additionally, the present invention also includes the above devices operated by a program stored in the computer (CPU or MPU) of a system or a device connected to the devices to realize the function of the above embodiments and to operate the devices by providing a program code of the software for realizing the function of the above embodiments.
[0079] In this case, the functions of the above embodiments are realized by the program code of the software. The program code and a unit for providing the program code for the computer, for example, a storage medium storing the program code configure the present invention.
[0080] As a storage medium storing the program code can be a floppy disk, a hard disk, an optical disk, a magneto-optical disk, CD-ROM, a magnetic tape, a nonvolatile memory card, ROM, etc.
[0081] Furthermore, the present invention obviously includes the program code not only in the realization of the functions of the above embodiment by executing the program code provided for the computer, but also in the realization of the functions of the above embodiments in cooperation with the OS (operating system) operated in the computer, or other application software, etc.
[0082] Additionally, the present invention obviously includes the program code in the realization of the functions of the above embodiments when the program code is stored in the memory of a computer function extension board or a function extension unit connected to the computer, and the CPU, etc. in the function extension board or the function extension unit performs a part or all of the actual process according to an instruction of the program code.
[0083] As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the present invention is not limited to the specific embodiments thereof expect as defined in the appended claims. | To precisely approximate the nonlinear output characteristic of an output device and enable high-precise color reproduction, a method is provided to convert a device-independent color space into an output device-dependent color space, comprising the steps of: inputting a colorimetry value of a color patch output by the output device and represented in the device-independent color space; extracting a colorimetry value close to a conversion target value represented in the device-independent color space, from the input colorimetry value; and performing, according to a distance between the input and extracted colorimetry values in the device-independent color space, a weighting process for a color value corresponding to the extracted colorimetry value and represented in the output device-dependent color space to obtain a color value corresponding to the input colorimetry value and represented in the output device-dependent color space. | 6 |
1. FIELD OF THE INVENTION
This invention relates generally to release mechanisms for supporting a survival craft such as a lifeboat or capsule from a ship or structure. More specifically, method and apparatus for testing the hook mechanism attached to and supporting the survival craft in the stored position is provided.
2. BACKGROUND OF THE INVENTION
Ships and offshore structures are supplied with lifeboats, capsules or other survival craft that can be used in an emergency to evacuate personnel from the vessel or structure. Such craft must be quickly accessible for use in case of an emergency. The craft have one or more release hooks used to support the craft from a davit. The davit includes cables and a winch mechanism that may be used to lower the craft to the water surface and raise the craft from the water. The release hook mechanism on the craft is normally operated when the craft is on the surface of the water. Since the release hook mechanisms are used infrequently, testing them periodically to determine that the release hooks are in operable condition is necessary. To insure operability, regulations require those release hook mechanisms be tested under no load and under an overload condition. It is current practice to simulate or launch the survival craft to determine that the release mechanism is operable under no load. To test under a load, it is current practice to place a load in the survival craft, lower the survival craft to a position just above the water surface and then operate the hook release mechanism on the craft.
A variety of models of davits and release hook mechanisms are approved for supporting the emergency craft. One hook is required on capsules, rescue boats and similar vessels and two hooks, which must release simultaneously, are required on lifeboats. The release lever mechanism for releasing the hooks is normally found inside the craft.
Regulations of the U.S. Coast Guard/Solas/IMO require that the release mechanism be tested once every five years. These regulations apply to U.S. and foreign flag vessels operating anywhere in the world. Many other countries also require that the support and release hook mechanism of the survival craft on their flag state vessels or structures in their territorial waters be periodically tested for operability. Resolution MSC 66/24 of the International Maritime Organization (IMO) requires that the release mechanism shall have two release capabilities: a normal release capability that will release a survival craft when it is waterborne (no load on the hooks) and an on-load release capability that will release the lifeboat with a load on the hooks. The on-load release capability should be demonstrated under any condition of loading from no load to a load of 1.1 (110%) times the total mass of the lifeboat when loaded with its full complement of persons and equipment.
There is need for a method and apparatus for testing the release hooks on capsules and similar vessels under a load required by regulations without launching the survival craft from the davit. Such a method and apparatus should make possible safer, less expensive testing and testing, if needed, more frequently. This will contribute to the safety and protection of life and property in sea operations.
SUMMARY OF THE INVENTION
Apparatus is provided for performing tests of release hook mechanisms on survival craft, capsules or other vessels. The apparatus includes a means for applying force, such as a hydraulic cylinder, and means for measuring the force applied.
A method is provided for placing a rigid test structure between a davit and the release hook mechanism support of a survival craft, capsule or other vessel such that a selected load can be applied to the hook while the release hook mechanism is released without launching the survival craft from its davit to the water. A hydraulic cylinder may apply the load and a load cell can measure the load. The test structure apparatus may be attached to the davit and to the release hook mechanism on the survival craft, capsule or other vessel by two padeyes that are normally used to attach the maintenance pendants or other attachment points.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1(a) shows the side view of a lifeboat supported in a davit.
FIG. 1(b) shows the front end view of the lifeboat and davit.
FIG. 2 shows a drawing of one embodiment of the apparatus of this invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1(a), lifeboat 10 is shown supported by davit 12. Support of the boat is through release hook assembly 14 on each end of the boat. The boat may be lowered or raised using winch 16, drum 18 and other mechanisms well known in the art of davit systems. Release hook assembly 14 is attached to the hull of boat 10 to support the boat under all working loads and includes hook release 13 and padeye 15. Such release hook mechanisms are available, for example, under the names VIKING, ROTTMER, TITAN, TOR and BG-7. Other release hook mechanisms are known in the art. The sizes and designs of the release hook assemblies may vary.
FIG. 1(b) shows the front end view of boat 10 and davit 12 of FIG. 1(a). Maintenance pendant 20 is attached to davit 12 by the upper end of pendant 20. The lower end of pendant 20, shown in its stored position hooked to the platform of davit 12, may be released and lowered to attach it to padeye 15 in release hook assembly 14. Pendant 20 may be used as a backup support for boat 10 when personnel enter boat 10 in its stored position to insure that boat 10 will not drop to the water in the event cable 22 of davit system 12 is inadvertently released from hook 13. Hook 13, sometimes called a "release gear hook," operates directly on ring 23, which may be a D-ring or other form of a ring, which is attached to cable 22. Hook 13 is normally actuated remotely from the console of boat 10 such that ring 23 is released from the hook, thereby releasing boat 10 from davit 12.
One embodiment of the apparatus of this invention, which can be used to place a selected load on hook 13 to insure that the hook can be remotely actuated in the presence of a load, is shown in FIG. 2. Beam 25 provides for rigid attachment of a lifeboat or other vessel to a davit during the testing method provided by this invention. Beam 25 has upper padeye 27 and lower padeye 29 rigidly attached to the beam. Padeyes may be attached by a bar or bolts extending through beam 25 such that alternate padeyes may be used or other removable mechanisms may attach padeyes or they may be permanently attached. For example, a single padeye or a clevis padeye may be attached to beam 25, the padeyes being adapted to the padeyes on the davit and release hook assembly where a test is to be performed. Lateral member 31 is attached to beam 25 such that it has sufficient strength to apply the test load of the inventive apparatus. Lateral member 31 may be attached by welding. Release gear hook 13 is a part of release hook assembly 14, shown in FIG. 1(a). Round link or D-ring 35 is adapted to and sized to engage hook 13 of the release hook assembly on the boat to be tested. Ring 35 can be connected by shackles 30 or other means known in the art to load cell 37, which is suitable for measuring loads applied. Dynalink Company supplies a suitable load cell. Model MSI 7200 fitted with two shackles may be used. Load bearing rod 38, having an eye at one end, is attached to load cell 37 by shackle 30 or other means. Rod 38 extends through lateral member 31 and hydraulic cylinder 40 and may be threaded to be held in place by hex nut 39. Hydraulic cylinder 40 is preferably adapted for center-hole loading, but other arrangements for applying applied loads to rod 38 may be used. A hand-operated hydraulic pump may power hydraulic cylinder 40 to extend the cylinder and place tensile loading on rod 38. A single-acting center-hole hydraulic cylinder available from Power Team Co., Mod. RH-203, having a 20-ton capacity, is suitable for some applications. Alternatively, the applied load may be applied by a screw mechanism, a pneumatic cylinder or other means commonly known in industry, which is used in place of hydraulic cylinder 40.
In another embodiment of the apparatus of this invention, load cell 37 may be replaced by strain gauge 50 (FIG. 2). Strain gauge 50 serves the same purpose as load cell 37, measuring the tensile force applied to ring 35 in hook 13.
The method for testing a release hook mechanism according to this invention is as follows, referring to FIG. 1 and FIG. 2: [1] check that release hooks 13 are closed and that winch 16 on davit 12 is working; [2] detach and remove maintenance pendants 20 from davit 12; [3] for each hook that is to be tested, attach upper padeye 27 of the test apparatus to davit 12 in place of the maintenance pendant; [4] slowly lower boat 10 using winch 16 until lower padeye 29 on the test apparatus can be attached to maintenance lug 15 of release hook assembly 14 and attach the padeye; [5] lower the boat until the weight is completely transferred from launch cables 22 to beam 25 of the test apparatus; [6] release the brake on the winch and payout additional cable and detach launch cables 22 from boat 10; [7] attach ring 35 to hook 13 of the release hook assembly and rig up the test fixture to apply and measure loads using hydraulic cylinder 40 and test cell 37; zero out test cell 37; [6] pump hydraulic cylinder 40 to apply a selected load to the hook mechanism, which may be equal to 1.1 times (110% of) the maximum working load of the boat; and [7] one person enter the boat and remotely actuate the hook on the boat and observe whether the hook releases. The test is now complete. After the test, ensure that the release gears closed then reset the release gear and install the safety pin, remove the hydraulic cylinder, load cell and test ring from the test apparatus, and reinstall the launch cables back in the release hook 13 and raise the boat to remove lower padeye 29 from release assembly 14. Then raise boat 10 back to its fully stored position and remove upper padeye 27 of the test apparatus from davit 12. Then reattach maintenance pendant 20 to davit 12.
A suitable material for the beams of the test apparatus is ASTM A-500 Gr. B steel or equivalent. Welding should be in accord with American Bureau of Shipping requirements.
Although the present invention has been described with reference to specific details, it is not intended that such details should be regarded as limitations upon the scope of the invention, except as and to the extent that they are included in the accompanying claims. | Apparatus and method are provided for testing the release hook mechanism used to release an emergency survival craft from its davit. The test is performed with a selected load applied to the hook mechanism, and is designed to satisfy regulations for no-load and on-load testing of release mechanisms. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit of priority under 35 U.S.C.§119 to Japanese Patent Application No. 2002-210666, filed on Jul. 19, 2002, the entire contents of which are incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a manufacturing method of a semiconductor device and the semiconductor device, and particularly relates to a manufacturing method of a semiconductor device in which semiconductor elements having favorable characteristics are formed and the semiconductor device.
[0004] 2. Description of the Related Art
[0005] In recent semiconductor devices, in order to achieve a reduction in the resistance of polysilicon wiring and a diffusion layer, a salicide metal layer is formed on the surface sides thereof. In forming the salicide metal layer, the formation of the uniform salicide metal layer on the polysilicon wiring and a wiring layer is demanded. A manufacturing process to form such a salicide metal layer is disclosed, for example, in Japanese Patent Laid-open No. 8-250716.
[0006] The manufacturing process of a related semiconductor device, which is disclosed in Japanese Patent Laid-open No. 8-250716 and so on, will be explained based on FIG. 1 to FIG. 3. FIG. 1 is a diagram showing a section of the related semiconductor device before the salicide metal layer is formed, and FIG. 2 is a diagram showing a section of the related semiconductor device after the salicide metal layer is formed. FIG. 3 is a plan view of FIG. 2.
[0007] As shown in FIG. 1, to form the uniform the salicide metal layer, cleaning with dilute HF is performed before the salicide metal layer is formed. Namely, oxide films and particles, which are naturally formed on the surfaces of P + diffusion regions 10 and 10 , the surfaces of N + diffusion regions 12 and 12 , and the surfaces of the gate electrodes 14 made of a polysilicon layer, are removed.
[0008] Thereafter, as shown in FIG. 2, the salicide metal layer is formed on the surfaces of the P + diffusion regions 10 and 10 , the surfaces of the N + diffusion regions 12 and 12 , and the surfaces of the gate electrodes 14 made of the polysilicon layer.
[0009] However, in the related manufacturing method, there is a problem that during cleaning treatment with dilute HF, a silicon oxide film (SiO 2 ) which forms a buried insulating film 20 for element isolation dissolves due to the dilute HF. In other words, there is a problem that SiO 2 and HF react with each other as shown in the following formula to thereby precipitate water mark.
SiO 2 +4HF→SiF 4 +2H 2 O
[0010] Particularly as shown in FIG. 3, when this precipitated water mark 30 adheres to the surfaces of P + diffusion regions 10 and 10 , the surfaces of N + diffusion regions 12 and 12 , and the surfaces of the gate electrodes 14 made of the polysilicon layer, the water mark 30 functions like a mask material. Hence, as shown in FIG. 2, the salicide metal layer is not formed in portions corresponding to the water mark 30 , and as a result, the uniform saliside metal layer cannot be obtained. If the uniform salicide metal layer is not formed, the resistance of the P + diffusion regions 10 and 10 , the N + diffusion regions 12 and 12 , and the gate electrodes 14 made of the polysilicon layer increases, which deteriorates characteristics of MISFETs as semiconductor elements.
[0011] Moreover, in the semiconductor device shown in FIG. 2, the height of the buried insulating film 20 and the height of the gate electrode 14 are different, thereby a step occurs between the buried insulating film 20 and the gate electrode 14 . Therefore, there is a problem that when an interlayer dielectric is formed thereon, the planarity of the interlayer dielectric is deteriorated.
SUMMARY OF THE INVENTION
[0012] In order to accomplish the aforementioned and other objects, according to one aspect of the present invention, a manufacturing method of a semiconductor device, comprises:
[0013] forming a buried insulating film in a semiconductor substrate;
[0014] forming semiconductor elements isolated by the buried insulating film;
[0015] cleaning a surface side of the semiconductor substrate with a cleaning solution; and
[0016] covering a surface side of the buried insulating film with a protective film before the step of cleaning the surface side of the semiconductor substrate, wherein a protective film is resistant to the cleaning solution.
[0017] According to another aspect of the present invention, a semiconductor device, comprises:
[0018] a buried insulating film which is formed in a semiconductor substrate;
[0019] semiconductor elements which are formed on the semiconductor substrate and which are isolated by the buried insulting film; and
[0020] a protective film which covers all of a surface side of the buried insulating film but which does not cover at least a region in which a salicide metal layer of the semiconductor element is formed, wherein the protective film is resistant to a hydrofluoric acid based solution.
[0021] According to another aspect of the present invention, a semiconductor device, comprises:
[0022] a buried insulating film which is formed in a semiconductor substrate;
[0023] MISFETs which are formed on the semiconductor substrate and which are isolated by the buried insulating film;
[0024] a protective film which covers all of a surface side of the buried insulating film and which is resistant to a hydrofluoric acid based solution; and
[0025] a salicide metal layer which is formed on source/drain diffusion regions of the MISFET and which is formed in a self-alignment manner relative to the protective film.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] [0026]FIG. 1 is a sectional view explaining a manufacturing process of a related semiconductor device (cleaning treatment);
[0027] [0027]FIG. 2 is a sectional view explaining the manufacturing process of the related semiconductor device (salicide metal layer forming processing);
[0028] [0028]FIG. 3 is a plan view of the semiconductor device in FIG. 2;
[0029] [0029]FIG. 4 is a sectional view explaining part of a manufacturing process of a semiconductor device according to a first embodiment;
[0030] [0030]FIG. 5 is a sectional view explaining part of the manufacturing process of the semiconductor device according to the first embodiment;
[0031] [0031]FIG. 6 is a sectional view explaining part of the manufacturing process of the semiconductor device according to the first embodiment;
[0032] [0032]FIG. 7 is a sectional view explaining part of the manufacturing process of the semiconductor device according to the first embodiment;
[0033] [0033]FIG. 8 is a sectional view explaining part of the manufacturing process of the semiconductor device according to the first embodiment;
[0034] [0034]FIG. 9 is a sectional view explaining part of the manufacturing process of the semiconductor device according to the first embodiment;
[0035] [0035]FIG. 10 is a sectional view explaining part of a manufacturing process of a semiconductor device according to a second embodiment;
[0036] [0036]FIG. 11 is a sectional view explaining part of the manufacturing process of the semiconductor device according to the second embodiment;
[0037] [0037]FIG. 12 is a sectional view explaining part of the manufacturing process of the semiconductor device according to the second embodiment;
[0038] [0038]FIG. 13 is a sectional view for explaining an example of a case where a wiring layer is formed in the semiconductor device according to the second embodiment; and
[0039] [0039]FIG. 14 is a circuit diagram for explaining an example of a case where an SRAM cell includes MISFETs shown in FIG. 13.
DETAILED DESCRIPTION OF THE EMBODIMENTS
First Embodiment
[0040] In the first embodiment, by covering at least the surface of a buried insulating film with a protective film resistant to dilute HF before cleaning a semiconductor device with dilute HF, dissolution of the buried insulating film at the time of cleaning with dilute HF is avoided. Further details will be given below.
[0041] First, as shown in FIG. 4, a buried insulating film 102 is formed in a semiconductor substrate 100 , for example, made of silicon. In this embodiment, the buried insulating film 102 is formed by a silicon oxide film (SiO 2 ). Additionally, in this embodiment, the buried insulating film 102 is formed by an STI manufacturing process. Subsequently, an N-type well 110 is formed by implanting impurity ions such as arsenic into the surface side of the semiconductor substrate 100 , and a P-type well 112 is formed by implanting impurity ions such as boron into the surface side of the semiconductor substrate 100 .
[0042] Thereafter, as shown in FIG. 5, an insulating film such as a silicon oxide film and a polysilicon layer are formed on the surface of the semiconductor substrate 100 , and these insulating film and polysilicon layer are etched in a predetermined pattern by RIE (Reactive Ion Etching), so that gate insulating films 114 and 116 and gate electrodes 120 and 122 are formed. Then, by covering a region corresponding to the P-type well 112 and a predetermined region of the N-type well 110 with a resist or the like and implanting the impurity ions such as boron, P + diffusion regions 130 and 130 are formed. One of these p + diffusion regions 130 and 130 becomes a source diffusion region and the other thereof becomes a drain diffusion region. Subsequently, contrary to the above, by covering a region corresponding to the N-type well 110 and a predetermined region of the P-type well 112 with the resist or the like and implanting the impurity ions such as arsenic, N + diffusion regions 132 and 132 are formed. One of these N + diffusion regions 132 and 132 becomes a source diffusion region and the other thereof becomes a drain diffusion region. Hence, a P-type MISFET and an N-type MISFET each with an LDD structure (Lightly Doped Drain Structure) are formed.
[0043] Next, as shown in FIG. 6, an insulating film 140 is formed on the surface of the semiconductor substrate 100 . In this embodiment, the insulating film 140 is formed of a silicon nitride film (SiN). Then, a resist 142 is formed and patterned on the insulating film 140 so as to cover an upper portion of the buried insulating film 102 .
[0044] Thereafter, as shown in FIG. 7, by etching the insulating film 140 by RIE, sidewalls 150 and 152 are formed on the side of the gate electrodes 120 and 122 , and a protective film 154 which covers all the surface side of the buried insulating film 102 is formed on the buried insulating film 102 . Namely, by etching back the insulating film 140 , the sidewalls 150 and 142 are formed in a self-alignment manner. Moreover, the protective film 154 is formed by leaving a portion of the insulating film 140 , which is covered with the resist 142 , by etching. This protective film 154 is formed so as to cover all the surface side of the buried insulating film 102 and so as not to cover at least a region in which an undermentioned salicide metal layer is formed. Subsequently, a natural oxide film and particles on the surface of the semiconductor substrate 100 are removed by cleaning with dilute HF. Since the buried insulating film 102 is covered with the protective film 154 at the time of this cleaning with dilute HF, the dissolution of SiO 2 can be prevented, which can prevent the generation of water mark.
[0045] Thereafter, as shown in FIG. 8, salicide metal layers 160 , 162 , 170 , and 172 are formed on the surface sides of the polysilicon layers of the gate electrodes 120 and 122 and the surface sides of the diffusion regions 130 and 132 . In this embodiment, the salicide metal layers 160 , 162 , 170 , and 172 are formed as follows. Namely, a high melting point metal film is formed on the surface side of the semiconductor substrate 100 . This high melting point metal film is made of, for example, Ti, Mo, W, Ni, or the like. Since, as described above, the water mark is not generated when this high melting point metal film is formed, it is possible to form the uniform high melting point metal film. Then, by subjecting it to thermal processing, the salicide metal layers 160 and 170 are formed on the surface sides of the gate electrodes 120 and 122 in a self-alignment manner, and the salicide metal layers 162 and 172 are formed on the surface sides of the diffusion regions 130 and 132 in a self-alignment manner relative to the protective film 154 .
[0046] Subsequently, as shown in FIG. 9, a silicon oxide film is formed on all the surface of the semiconductor substrate 100 . Since the protective film 154 is formed on this occasion, a step between the gate electrodes 120 and 122 and the buried insulating film 102 is reduced, leading an improvement in the planarity of the silicon oxide film. Then, by planarizing the silicon oxide film by CMP (Chemical Mechanical Polishing), an interlayer dielectric 180 is formed.
[0047] As described above, according to the semiconductor device of this embodiment, the buried insulating film 102 is covered with the protective film 154 before cleaning with dilute HF, whereby the precipitation of water mark from the buried insulating film 102 during cleaning treatment can be avoided. Hence, the uniform salicide metal layers 160 , 162 , 170 , and 172 can be formed, and the characteristics of MISFETs can be maintained favorably.
[0048] Moreover, by covering the buried insulating film 102 with the protective film 154 , the step between the buried insulating film 102 and the gate electrodes 120 and 122 can be reduced, resulting in improved planarity when the interlayer dielectric is formed thereon.
[0049] Furthermore, a material of the protective film 154 is the insulating film 140 and therefore the material of the protective film 154 is the same as that of the sidewalls 150 and 152 , whereby the protective film 154 can be obtained without adding a new film forming process.
Second Embodiment
[0050] In the second embodiment, the parasitic capacitance of the MISFET is increased by greatly extending the protective film 154 in the aforementioned first embodiment to the sides of the diffusion regions 130 and 132 . Further details will be given below.
[0051] A manufacturing method of a semiconductor device according to this embodiment is the same as that in the aforementioned first embodiment in FIG. 4 and FIG. 5. However, a change is made to the size of the resist 142 in the aforementioned first embodiment. Namely, as shown in FIG. 10, a resist 242 is formed on the insulating film 140 , and the resist 242 is not only formed on the buried insulating film 102 but also formed so as to extend onto the P + diffusion region 130 and the N + diffusion region 132 , so that it is formed larger.
[0052] Then, as shown in FIG. 11, by etching the insulating film 140 by RIE, the sidewalls 150 and 152 are formed on sidewall portions of the gate electrodes 120 and 122 , and a protective film 254 , which covers the buried insulating film 102 and a portion of each of the diffusion regions 130 and 132 , is formed on the buried insulating film 102 . Namely, by etching back the insulating film 140 , the sidewalls 150 and 152 are formed in a self-alignment manner. Moreover, the protective film 254 is formed by leaving a portion of the insulating film 140 , which is covered with the resist 242 , by etching. This protective film 254 is formed so as to cover all the surface side of the buried insulating film 102 and a portion of each of the diffusion regions 130 and 132 and so as not to cover at least a region in which the undermentioned salicide metal layer is formed. Subsequently, a natural oxide film on the surface side of the semiconductor substrate 100 and particles are removed by cleaning with dilute HF. Also in this embodiment, since the buried insulating film 102 is covered with the protective film 254 at the time of this cleaning with dilute HF, the dissolution of SiO 2 can be prevented, which can prevent the generation of water mark.
[0053] The manufacturing process thereafter is the same as that in the aforementioned first embodiment. Namely, as shown in FIG. 12, the salicide metal layers 160 , 162 , 170 , and 172 are formed on the surface sides of the polysilicon layers of the gate electrodes 120 and 122 and the surface sides of the diffusion regions 130 and 132 in a self-alignment manner. Subsequently, a silicon oxide film is formed on all the surface of the semiconductor substrate 100 . Since the protective film 254 is formed on this occasion, a step between the gate electrodes 120 and 122 and the buried insulating film 102 is reduced, leading an improvement in the planarity of the silicon oxide film. Then, by planarizing the silicon oxide film by CMP (Chemical Mechanical Polishing), the interlayer dielectric 180 is formed.
[0054] As described above, also according to the semiconductor device according to this embodiment, by covering the buried insulating film 102 with the protective film 254 , the precipitation of water mark from the buried insulating film 102 during cleaning treatment can be avoided, and hence the uniform salicide metal layers 160 , 162 , 170 , and 172 can be formed. Consequently, the characteristics of the MISFETs can be maintained favorably.
[0055] Moreover, by covering the buried insulating film 102 with the protective film 254 , the step between the buried insulating film 102 and the gate electrodes 120 and 122 is reduced, resulting in improved planarity when the interlayer dielectric is formed thereon.
[0056] Furthermore, a material for the protective film 254 is the same insulating film 140 used for the sidewalls 150 and 152 , whereby the protective film 254 can be obtained without adding a new film forming process.
[0057] Additionally, the protective film 254 is formed in such a manner as to cover as far as a portion of each of the diffusion regions 130 and 132 , whereby the diffusion regions 130 and 132 function as capacitors, and the parasitic capacitance of the MISFET can be increased. For example, it is assumed that a wiring layer 300 which electrically connects the diffusion region 130 and the diffusion region 132 is formed across the protective film 254 as shown in FIG. 13. In this case, the protective film 254 is sandwiched as a capacitor dielectric between the wiring layer 300 and the diffusion region 130 , and the protective film 254 is also sandwiched as a capacitor dielectric between the wiring layer 300 and the diffusion region 132 , so as to constitute capacitors. Therefore, the parasitic capacitances of two MISFETs can be increased, leading to an improvement in the drive capabilities of the MISFETs.
[0058] Hence, for example, by using the MISFETs according to this embodiment for an SRAM cell such as shown in FIG. 14, the data line drive capability of the SRAM cell can be improved. Namely, when a P-type MISFET in FIG. 13 is taken as QP and an N-type MISFET therein is taken as QN, in the SRAM cell in FIG. 14, one complementary MIS inverter is composed of a MISFET QP 1 and a MISFET QN 1 , and the other complementary MIS inverter is composed of a MISFET QP 2 and a MISFET QN 2 . A MISFET QN 3 and a MISFET QN 4 are selection transistors which are connected to bit lines BL as data read lines. Gates of these MISFET QN 3 and MISFET QN 4 are connected to a word line WL.
[0059] When the complementary MIS inverters structured as shown in FIG. 13 are used in such an SRAM cell, capacitors C 1 and C 2 are added to data output nodes N 1 and N 2 of the complementary MIS inverters, respectively. Hence, the drive capabilities of the data output nodes N 1 and N 2 for the bit lines BL can be raised.
[0060] It should be mentioned that the present invention is not limited to the aforementioned embodiments, and various changes may be made therein. For example, although in the aforementioned embodiments, in FIG. 7 and FIG. 11, a hydrogen fluoride (HF) solution is used as a solution used when the surface side of the semiconductor substrate 100 is cleaned, other hydrofluoric acid based solutions such as ammonium fluoride (NH 4 F) may be used. In this case, a protective film resistant to the hydrofluoric acid based solution is required to be used as the protective films 154 and 254 . However, hydrogen fluoride (HF) has a higher etching rate for oxide, and hence the hydrogen fluoride (HF) solution is the most suitable as a cleaning solution out of hydrofluoric acid based solutions.
[0061] Moreover, in FIG. 7 and FIG. 11, the solution used when the surface side of the semiconductor substrate 100 is cleaned is not limited to a hydrofluoric acid based solution, and any other cleaning solution having an equal cleaning effect can be used. In this embodiment, a protective film resistant to this used cleaning solution is required to be used as the protective films 154 and 254 .
[0062] Furthermore, although the MISFETs are given as an example of semiconductor elements isolated by the buried insulating film 102 in the aforementioned embodiments, other semiconductor elements may be formed and isolated by the buried insulating film 102 . | A manufacturing method of a semiconductor device disclosed herein, comprises: forming a buried insulating film in a semiconductor substrate; forming semiconductor elements isolated by the buried insulating film; cleaning a surface side of the semiconductor substrate with a cleaning solution; and covering a surface side of the buried insulating film with a protective film before the step of cleaning the surface side of the semiconductor substrate, wherein a protective film is resistant to the cleaning solution. | 7 |
BACKGROUND OF THE INVENTION
1. The Field of Invention
This invention relates in general to vacuums and animal waste and in particular to vacuums that use a disposable container and pickup tool. The emphasis here is on a potable hand held powered device that uses a vacuum airflow to remove animal waste and in the process collect it in a disposable container which along with the pick up tool can easily be removed from the device and disposed of cleanly with ease.
2. The Description of Related Art
In order to provide background information so that the invention may be completely understood and appreciated in its proper context, reference may be made to a number of prior art patents. Their patent numbers will be listed below when the item is patented. However, there are processes in use which are not necessarily patented whose description and use sheds light on the existing problems of which this new invention solves.
There is a problem for people in using lawn or grassy areas, or sidewalks where animals such as dogs have been. This problem is widespread, especially, but not limited to, dog owners backyards and city streets in crowded metropolitan areas. These animals leave behind their waste. This is particularly obnoxious to people when they are walking, playing or servicing the area and they happen to step in the waste or roll over the waste with the wheels or some other part of their equipment. The problems also extends to health considerations and surface deterioration/discoloration from the natural deterioration of this waste. People have solved this problem by picking up the waste using various tools however each device has its own drawbacks which I will be pointing out, and of which my invention solves.
There is in use a little, garden shovel which is used to scoop up the waste and deposit it in a bucket lined with a disposable bag. But the problems here are stooping or bending repetitively, getting close to the smelly waste, and getting debris on the shovel. My machine is operated from a standing position with no bending or stooping and there is no cleaning of the tools as they are immediately disposed of.
Some dog walkers carry with them plastic baggies which they use to wrap around the waste with their hands, or use a tool to push the waste into. This brings the owner terribly close to the waste and if a tool is used in the process, some waste is left on the tool which must later be cleaned. Not only is this process obnoxious but embarrassing as well as neighbors can see what the owner is carrying. My device keeps the owner at a comfortable distance from the waste and since the waste goes directly into a container no one is embarrassed by onlookers and since the pickup tool and container are disposable there is no cleanup. Just a simple slide out from the machine and a toss into a trash container and they are done.
Another tool is similar to two shovels at the end of long sticks connected midway down the poles as a pair of scissors. This tool keeps the person at a distance from the waste but the problem of bending is replaced with teaming to effectively wield the long handled device to pick up the waste and then dispose of it in another container. But this tool still needs to be cleaned after its use and this is a particularly disgusting task. My hand held machine collects the debris in a long disposable intake lube which is hand controlled for ease of collection and no cleaning is required. All places that come into contact with the debris are disposed of after each use.
Another invention, U.S. Pat. No. 4,549,329, is a vacuum which will intake the debris through a tube. This machine is self cleaning in that after each use it puts down a puddle of water to be vacuumed up and this little mount of water is supposed to dissolve the waste that stuck to the interior of the tube. This device is not as clean as it proposes. The little mount of water that it deposits is not sufficient to clean some waste. It is also a disgusting process in that it must be emptied when filled up and then the waste is more fluid and obnoxious that before. This tool also requires the person to get somewhat close to the smelly obnoxious waste or debris, by stooping or bending to use the tool. My invention, although it used the concept of a long tube as a pickup device is better since it is disposable, and never needs cleaning. It is also better in that the intake tube/container port is easily pointed m and brought near the waste for pickup.
Still another group of tools am the blower/vacuum devices. Please refer to the following U.S. Pat. Nos. 4,325,163, 4,644,606, 4,461,055, 4,870,714 and 5,222,275. These machines are either electric or gas powered blower/vacuums. The blower portion works because an air flow is created with an impeller (fan) connected to the motor/engine, Air is sucked into the machine by the impeller, across the blades of the impeller and pushed out the blower tube. A vacuum is created at the intake end. When the vacuum portion is desired to be used a switch of equipment puts a bag on the blower end and a long tube is put on the intake end. Waste is sucked into the machine via the intake tube, across the impeller and out the blower end and into the bag. However, these types of machines will not work as animal waste vacuums as the waste and debris is smashed and crunched when it rams into the impeller or cut by a mulching blade and this would make a severe mess and clog up the machine. My machine collects the debris before the debris reaches the impeller. The container allows the waste to collect outside of the air flow path and before it gets to the impeller.
There is also another group of portable vacuums, please refer to these U.S. Pat. Nos., 4,325,162, 4,570,286 and 4,944,065 that use a long intake tube and a portable vacuum. These vacuums do not use the combination of disposable pickup tools and disposable storage containers and as pointed out earlier with other devices cleaning these pieces of equipment after each use would be problematic.
Whatever the precise merits, features and advantages of the above cited references, none of them achieves or fulfills the purposes of the current disposable intake tube and container of the present invention.
SUMMARY OF THE INVENTION
Accordingly, it is a principal object of the present invention to provide a vacuum operated device and tool with characteristics that will enable the user to pick up waste and debris with less bending and less stooping.
It is also another principal object of the present invention to provide a vacuum operated device with a disposable intake tube and disposable container which connects and disconnects easily to the vacuum source.
It is also another principal object of the present invention to provide a vacuum operated device with a disposable intake tube and disposable container which are made and marketed at a very low cost so as to allow the user to dispose of the tube and container after each use.
It is another principal object of the present invention to provide a vacuum device with a disposable pick up tube and disposable storage container which are used to pick up noxious waste and debris and be more recyclable, more biodegradable, easier to dispose of, and more environmentally friendly than existing tools or methods.
It is another principal object of the present invention to provide a way to pick up waste and debris using a vacuum source with a disposable intake tube and container in which it is believed that the air pressure in the container portion of the device is sufficiently less then the air pressure in the other portions of the device so as to create an air pressure drop which allows other forces to act on the waste and thereby directing the movement of the waste.
It is another principal object of the present invention to provide a vacuum device with a disposable pick up lube and disposable storage container that will pick up waste and debris in a much cleaner and less noxious manner and allow disposal to be quicker and easier than with existing methods.
Still another principal object of the present invention is to provide a vacuum device with a disposable pick up tube and disposable storage container that is comfortable and easy to use so that the user simply walks around the area to be cleaned and by simple hand motions points the tip of the pick up tool at base of the waste and the waste is sucked up into and through the pick up tool and stored in either container or in the pick up tool itself depending upon the version the user has chosen to use.
Still another principal object of the present invention is to provide a vacuum device with a disposable pick up tube and disposable storage container which is portable and can be operated on its own self-contained power supply or can be plugged into a conventional electrical outlet.
Still another principal object of the present invention is to provide a vacuum device with a disposable pick up tube and disposable storage container having the aforementioned described advantageous objects which is lightweight and simple in construction, easy to use and maintain and can be made and sold at a reasonable cost.
Still another principal object of the present invention is to provide a superior vacuum device with a disposable pick up tube and disposable storage container that is both lighter in weight and more convenient to use and which functions in a more efficient manner for picking up animal waste and debris than any previous art.
Still another principal object of the present invention is to provide a vacuum device with a disposable pick up tube and disposable storage container in which the debris and waste are efficiently captured while directing the major portion of the exhaust air flow, and any entrained particles away from the user.
Still another principal object of the present invention is to provide a vacuum device with a disposable pick up tube and disposable storage container having sufficient power and light weight to provide a system well-suited for its intended use.
Still another principal object of the present invention is to provide a vacuum device with a disposable pick up tube and disposable storage container where the volume of the container, it is believed, is large enough compared to the intake tube and while considering the force of the vacuum to allow sufficient pressure drop in said container to allow the incoming debris and waste to be directed into and stored in said container.
Still another principal object of the present invention is to provide a vacuum device with a disposable pick up tube and disposable storage container whose pick up tool is sufficiently large enough to pick up animal waste and debris.
The invention is a hand held portable vacuum with at least three different configurations and all are specially designed with low cost intake tubes and containers which are intended to be disposed of after each and every use and they are designed to be used for the purpose of cleanly and easily picking up animal waste and other debris. The vacuum is sourced from a fan connected to but not limited to an electric motor, or an internal combustion engine which produces a sufficient amount of vacuum to draw the waste from its location through the pick up tube and into the storage container. The pick up tube is constructed from a suitable material whose characteristics meet the needs as intended and the material is to be either recyclable or biodegradable and environmentally friendly.
The present invention advantageously provides a vacuum system which provides a compact power unit that can accept and pass the full range of expected debris and waste from the pick up tube to the container and which directs the major portion of the exhaust air including entrained dust particles away from the user. Other objects and further scope of applicability of the present invention will become apparent from the detailed description to follow, taken in conjunction with the accompanying drawings in which like parts are designated by like reference characters.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of the complete unit of Version A of the present invention;
FIG. 2 is a perspective view of the complete unit of Version B of the present invention;
FIG. 3 is a perspective view of the complete unit of the vacuum version of Version C of the present invention;
FIG. 4 is a perspective view of the complete unit of the blower version of Version C of the present invention;
FIG. 5 is a top elevational view of the complete unit of Version A of the present invention;
FIG. 6 is a side elevational view of the complete unit of Version A of the present invention;
FIG. 7 is a front elevational view of the complete unit of Version A of the present invention;
FIG. 8 is an enlarged detail perspective view of the keeper device, item #7, of the present invention;
FIG. 9 is a representative view of the weave of the high porosity mesh suitable for use as item #16 of the present invention;
FIG. 10 is a side elevational view of the complete unit of Version B of the present invention;
FIG. 11 is an enlarged detail representative view taken along line 10--10 of the stopper of FIG. 10;
FIG. 12 is a top elevational view of the complete unit of Version B of the present invention;
FIG. 13 is a from elevational view of the complete unit of Version B of the present invention;
FIG. 14 is a side elevational view of the complete unit of the vacuum configuration of Version C of the present invention;
FIG. 15 is a top elevational view of the complete unit of the vacuum configuration of Version C of the present invention;
FIG. 16 is a back elevational view of the complete unit of the vacuum configuration of Version C of the present invention;
FIG. 17 is a front elevational view of the complete unit of the vacuum configuration of Version C of the present invention;
FIG. 18 is a perspective view of the debris collecting bag, #19 used in the vacuum configuration of Version C of the present invention;
FIG. 19 is a front view of the rubber grommet, #13, used in Version C of the present invention;
FIG. 20 is a side view of the rubber grommet, #13, used in Version C of the present invention;
FIG. 21 is a side elevational view of the complete unit of the blower configuration of Version C of the present invention;
FIG. 22 is a top elevational view of the complete unit of the blower configuration of Version C of the present invention;
FIG. 23 is a front elevational view of the complete unit of the blower configuration of Version C of the present invention;
FIG. 24 is a rear elevational view of the complete unit of the blower configuration of Version C of the present invention;
FIG. 25 is a side elevational view of the pick up tube used in Version C of the present invention;
FIG. 26 is and end view of the pick up tube used in Version C of the present invention.
FIG. 27 is a perspective view of a representative flexible sheet.
FIG. 28 is a perspective view of the storage container and the inlet hole for an alternate embodiment using the flexible sheet.
FIG. 29 is a perspective view of a representative sturdy cover to secure the flexible sheet to the storage container in the flexible sheet embodiment.
DETAILED DESCRIPTION
In view of the above mentioned objects and others, refer now to FIG. 1 for an overall drawing of one of the preferred embodiments of the invention, Version A. This version of the present invention, as dram in farther detail in FIGS. 5, 6 and 7, comprises a vacuum device having a power unit 5 with a rotatably mounted fan 2 of for inducing an air flow from an inlet 6 to an outlet 4. The unit is guided and directed by using the hand held handle 3. The pick up tube 1 of this vacuum device having sufficient diameter relative to the waste and debris to be picked up is connected to the vacuum source by simply slipping it into the inlet 6 of the power unit 5 which pulls the debris into and along the pick up tube 1. The pick up tool of Version A comprises a tube open at both ends with the exception of a keeper device 7 at the pick up end and a filtering device 16 at the air flow exit end. This keeper device 7 comprises a plastic ring that attaches to the end of the tube and this plastic ring has approximately 4 long finger-like tabs which come close together at a point just inside the end of the pick up tube. These tabs are made of a suitable material, such as a light weight plastic, that allows them to flex from their base to open at their tips to permit the waste and debris to pass and then close afterward to keep any waste or debris from passing through in the reverse direction. There is sufficient space between these tabs to allow a sufficient amount of vacuum to pass by the edges of these tabs to pick up the intended waste and debris and pull it into the tube 1 and continue moving the waste and debris through these tabs as the tabs flex open but not so much space between the tabs that any of the intended waste and debris may pass through the tabs when they are closed. In another embodiment this keeper device 7 is an integral part of the pick up tube 1. In this alternate embodiment the flexible tabs will still flex open and closed as waste and debris passes through, however they will be constructed as a continuation of the pick up tube end and they will be bent and inserted into the interior of the pick up tube. This embodiment works well if constructed using a cardboard tube. The filtering device 16 at the air flow exit end of the pick up tube 1 is designed in such a way that it will stop the intended waste and debris from passing any farther and entrap it in the tube 1 while allowing the air flow caused by the vacuum created by the motor 5 and fan 2 to continue and pass through the motor and fan to the outside. This Version A is designed to store the amount of waste picked up in one use and then it is intended to be disposed of. The pick up tube 1 and its components are made of recylable or biodegradable materials, such as plastic, paper or cardboard, and are environmentally friendly so that the daily use of these items will not cause an environmental hazard. This Version A of the present invention in intended to pick up a small mount of waste and debris and it's recommended use is for people to take with them when they take their pets for a walk. Version B and Version C are intended for uses where larger amounts of waste will need to be picked up.
Refer now to FIG. 2 for an overall drawing of another of the preferred embodiments of the invention, Version B. This version of the present invention, as drawn in further detail in Figs. 10, 12 & 13, comprises a vacuum device having a power unit 5 with a rotatably mounted fan 2 for inducing an air flow from an inlet 6 to an outlet 4. The pick up tube 17 of this vacuum device having sufficient diameter relative to the waste and debris to be picked up opens into and passes through the storage container 24 and is connected to the inlet 6 of the power unit which pulls the debris through the pick up tube 17 and into the storage container 24. The section of the pick up tool which passes through the storage container 24 comprises a cut out of most of the lower portion of the back half section of said tube 22 and a deflector tab 21 as seen in FIG. 11. Both the cutout 22 and the deflector tab 21 are sufficiently sized to accept and direct the expected range of waste and debris. There is also a filtering stopper device 16 which completely filters the air as is passes around the deflector 21 and through the remaining tail section of the pick up tube 17 and into the fan 2 and motor section 5. The debris passes through the intake tube 17 being carried by the vacuum air flow caused by the motor 5 and fan unit 2 until it hits the deflector 21 as seen in FIG. 11, at which time, it is believed, because of the lower air pressure in this section and the interruption in the inertia of the waste and debris the gravitation force of the earth pulls the waste and debris through the opening in the intake tube 22 and into the storage container 24. The remaining portion of the portion of the intake tube 23 which passes through the storage container, this is the first portion that is inside the storage container, keeps the waste and debris that has already been picked up from going back into the incoming pathway. Any smaller particles that bypass this container section are caught by the filter 16 in the tail section of the pick up tube 17. It is in the enlarged container space 24 of Version B that a larger amount of waste and debris can be collected. A typical place where this version would be used is in cleaning up a pet owners backyard.
Refer now to FIGS. 3 and 4 for two overall drawings of another of the preferred embodiments of the invention, Version C. This version of the present invention, as drawn in further detail in FIGS. 14, 15, 16 and 17 for the vacuum function and FIGS. 21, 22, 23 and 24 for the blower function. Both functions are created using a power unit 18 with a rotatably mounted fan 18 for inducing an air flow from an inlet 25 to an outlet 15. Said motor is cooled by air brought in through the openings 11. The inlet 25 is the source of the vacuum and the outlet 15 is the source for the blower. This power unit housing 10 easily mounts on top of the storage container 9 and has the means for locking in place by pressing the flange 26 of the base of the housing 10, to which the motor 18 and fan 18 are mounted to, onto and around the lip of the open top of the storage container 9 or any arrangement whereby the motor base and open portion of the container have the means for a lockable connection and an airtight seal. The pick up tube 14 for the vacuum function, FIGS. 14, 15, 16 and 17, having sufficient diameter relative to the waste and debris to be picked up is inserted into and through the upper side wall of the storage container 9 via a rubber grommet 13 which creates an airtight seal between the container 9 and the pick up tube 14. This storage container 9 may or may not have, at the discretion of the operator, a sealed flexible wailed storage filtering bag 19. This bag will fit neatly inside the storage container 9 and will have an opening to accept the intake tube 14. The opening of this filtering bag 27 is of sufficient size to accept the intake tube 14 and seal around the exterior of the tube and is reinforced at the opening with a more rigid support 10. This bag 19 is of sufficient porosity so as to entrap the expected range of waste and debris and still allow a sufficient amount of air flow through the porous walls, into the solid walled container 9 and out through the opening 25 which leads to the intake of the fan 18 and motor 18. The storage container 9 is connected to the power unit 18 which generates a vacuum which pulls the debris through the pick up tube 14 and into the storage container 9 and if so desired by the operator, into the bag 19. In an alternate construction, the rubber grommet 13 may be replaced with another setup, FIG. 27, comprising a flexible sheet, 18 with a hole in it's center 29. This hole 19 in the flexible sheet 28, is aligned over the hole 30 in the storage container, FIG. 28, in such a manner as to allow the end of the pick up tube 14 to pass through the flexible sheet 28 and into the storage container 9 while making an airtight seal between the pick up tube 14 and the storage container 9. This flexible sheet 28 is held in place by a sturdy cover 31, FIG. 29 which also has a similarly sized hole 32 in it's center. This sturdy cover 31 with it's centered hole 32 is also aligned over the two other holes 29 and 30 and also allows the pick up tube 14 to pass through it as well. This sturdy cover 31 is held in place and holds the flexible sheet 28 in place by suitable means. Still in another embodiment the sealed flexible walled storage filtering bag 19, may be replaced with the same bag and opening and support but have an opened top, or in yet another embodiment this bag may be any type of open top bag so as to allow the waste to fall into the bag and the air to flow to the vacuum intake 15. However, in such an embodiment as this, an air filter located inside the opening at the vacuum intake 15 will be necessary to entrap any remaining airborne waste. It is believed that the porousness of the bag becomes obsolete once the top is opened as the air flow would not longer be restricted.
For the blower function of Version C, FIGS. 21, 22, 23 and 24, the pick up tube 14 is removed from the rubber grommet 13 and is inserted into the fitting 15 for the exhaust air and directs the exhaust air through the end of the tube 14. This tube 14 in this position is now called the discharge tube 14.
The handle 12 is aligned in the same plane as the pick up tube or the discharge tube. This alignment aids the user in aiming the pick up tube for either function. The foregoing descriptions of these preferred embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. | The present invention advantageously provides a vacuum system which provides a compact power unit that can accept and pass the full range of expected debris and waste from the pick up robe to the container and which directs the major portion of the exhaust air including entrained dust particles away from the user. The invention discloses disposable pick up tubes and storage containers which are low cost and easy to use which achieve their purposes of picking up, storing and disposing of waste and debris simply and easily. | 4 |
FIELD OF THE INVENTION
The present invention relates to a method for launching counter-measures, such as flares and chaff, from a dispenser which is mounted on an aircraft. The invention also relates to an arrangement for storing and launching counter-measures, such as flares and chaff, comprising an elongate body with a plurality of compartments which are provided with openings and are separated in the longitudinal direction of the elongate body by partition walls and are used for storing the counter-measures, the arrangement being designed to be mounted on an aircraft of the aeroplane type, with the longitudinal direction of the elongate body essentially coinciding with the flight direction of the aircraft, and the counter-measures being connected to a firing control unit for feeding firing signals to the counter-measures. The counter-measures can consist of passive means, such as chaff foil or metal-coated glass fibres, but can also consist of flares, for example IR flares, or other active measures.
BACKGROUND OF THE INVENTION
An example of a previously known arrangement or dispenser which is used for launching counter-measures and is provided with compartments is described in our own patent U.S. Pat. No. 4,679,483. In this case, the dispenser is configured and mounted on the aeroplane in such a way that the counter-measures are launched obliquely rearwards and downwards relative to the aeroplane.
Another example of a dispenser is known from U.S. Pat. No. 4,524,670. In this case, the dispenser is mounted on the underside of the aeroplane for launching the counter-measures downwards relative to the aeroplane.
The above two examples are examples of counter-measure dispensers which in historical terms have been able to function well, i.e. to successfully divert enemy attack, for example in the form of a target-seeking missile, towards the decoy target. However, over the course of time, target-seeking functions have been developed further, and there is now therefore a greater possibility of distinguishing the decoy target from the aeroplane. For example, the target seeker can be specifically programmed to handle the preliminary phase of activation of counter-measures. Information which can be used in this connection is the direction in which the counter-measures are launched relative to the aeroplane. In principle, the target seeker expects the counter-measures to be launched downwards, obliquely rearwards, or possibly rearwards.
A particular problem in launching flares is that the flares need time to develop into fully active decoy targets. There is a risk that the flares will only become fully active decoy targets at such a great distance from the aeroplane that a target seeker will be able to continue to follow the plane without any great problem.
SUMMARY OF THE INVENTION
One object of the present invention is to make available a method for launching counter-measures and an arrangement for storing and launching the counter-measures which increase the possibility, compared to known techniques, of avoiding threats, for example in the form of target-seeking missiles, enemy aircraft or the like.
Another object is to prevent the occurrence of vibration disturbances which are primarily caused by inherent oscillations in compartments which have been emptied of counter-measures.
The objects of the invention are achieved by means of a method which is characterized in that the counter-measures are launched in a direction obliquely forwards and upwards relative to the aircraft, and in that, in order to facilitate launching of the counter-measures, a low dynamic pressure is created permanently across the dispenser's launch openings by means of fixed means acting on the air stream, and also by means of an arrangement characterized in that the arrangement is designed to be mounted on the top of the aircraft, and in that the compartments are provided with openings and are intended for launching the counter-measures in a direction obliquely forwards and upwards relative to the aircraft. By launching the counter-measures in the direction in accordance with our invention, a separating procedure unknown to today's target seekers is obtained. Re-programming to the novel separation procedure is not a successful solution since it is then more difficult to identify previously known separation procedures. By launching the flares in the direction according to our invention, the flares have time to develop to fully active decoy targets before they pass the main heat source of the plane pertaining to the heat generation of the jet engines.
In this connection it may be noted that it is known per se to arrange a launching device on a plane which launches bombs or missiles obliquely forwards, see U.S. Pat. No. 3,517,584. The object of doing this is to effect launching which does not affect the plane's speed and position despite the fact that very heavy objects are being launched. The solution is based on launching the bombs or missiles obliquely forwards by controlling guide rails. As soon as the bombs or the missiles leave the guide rails and thus the discharge opening, they lie in a rearwardly directed trajectory relative to the aeroplane and are only then activated. During the actual launch phase for a missile or a bomb, a hatch is opened which in the opened state has the task of reducing the air resistance in the slipstream. The slipstream is employed to quickly lift missiles or bombs away from the discharge opening. When closed, the hatches form an even, streamlined structure.
This launching of bombs or missiles in accordance with the above paragraph cannot be compared with the arrangement according to the invention for launching counter-measures, such as flares and chaff. Where counter-measures are concerned, it is lighter objects that are being launched and these objects are activated directly or shortly after they have left the discharge opening and in a first stage act near the aeroplane to create a favourable starting point for misleading radar, IR target seekers, or the like. On discharge, the air stream is disturbed such that the counter-measures can be kept near the aeroplane for as long as possible. The air stream is lifted over the discharge opening in order to minimize impact or relative wind against the counter-measures and to prevent transmission of vibrations to the aeroplane.
The counter-measures can advantageously be launched obliquely forwards and upwards and to the side. By adding in a lateral component, the launched counter-measures can be guided out further from the main body of the aeroplane. Such an arrangement reduces the risks of inadvertent collisions occurring between counter-measures and aeroplane body.
The compartments are suitably designed to slope forwards 30° to 60° and preferably about 45° relative to the aircraft.
It should be emphasized here that it is not just the compartments which control the direction of launching. It also depends on how the counter-measures, preferably in cartridge form, are arranged in the compartments. The cartridges can to a certain extent be turned in the compartments. The inclination of the cartridges can be altered relative to the longitudinal and transverse walls of the compartments. In addition, the cartridges can be arranged to lie with the opening side essentially diagonal relative to the openings of the compartments. In principle, all geometrically possible positions can be considered for acting on the direction of launching and may be used.
To make it easier to launch the counter-measures obliquely forwards and upwards, the elongate body of the arrangement is provided with fixed means acting on the air stream in order to permanently create a low dynamic pressure across the compartment openings. This reduces the forces which act on the counter-measures during the phase when they leave the compartments of the elongate body via the compartment openings. The effect on the counter-measures during the launching phase is less, the result of which is that the launching force can be limited and the risks of damage to the counter-measures is reduced. For example, breaks on flares can be avoided.
When a compartment has been emptied of its contents of counter-measures, the compartment can act as a barrel which oscillates at its inherent frequency. Under unfavourable conditions, extremely high noise levels can occur. The creation of a low dynamic pressure across the compartment openings has been shown to effectively counteract oscillations caused by the inherent frequencies of the compartments, since the low dynamic pressure near the openings of the compartments means low energy.
Low dynamic pressure across the compartment openings can be created in a number of ways and, in particular, several measures can be combined to produce a low dynamic pressure across the whole row of compartment openings.
According to an advantageous embodiment, the means for creating a low dynamic pressure across the compartment openings comprise a finish towards the front compartment of the elongate body at an upwardly directed angle, preferably of the order of 15°, formed in the upper part of the front end of the elongate body.
According to another advantageous embodiment, the means for creating a low dynamic pressure across the compartment openings comprise partition walls with top parts shaped with an upwardly directed angle, preferably of the order of 15°. The partition walls are advantageously designed with a not inconsiderable thickness, preferably in the range of 10 to 30 mm, for example 15 mm.
According to a further advantageous embodiment, the means for creating a low dynamic pressure across the compartment openings comprise rounded edges designed in the transverse direction of the elongate body near the compartment openings.
According to yet another advantageous embodiment, the means for creating a low dynamic pressure across the compartment openings comprise spoiler elements arranged on the upper part of the front end of the elongate body.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in greater detail below by way of illustration and with reference to the attached drawings, in which:
FIG. 1 a shows a side view of an aeroplane provided with an arrangement according to the invention for storing and launching counter-measures.
FIG. 1 b shows a front view of one half of an aeroplane according to FIG. 1 a with an arrangement according to the invention for storing and launching counter-measures.
FIG. 2 a shows a side view of an arrangement according to the invention for storing and launching counter-measures.
FIG. 2 b shows a top view of the arrangement according to FIG. 2 a.
FIG. 3 a shows the cross-flow for a sharp-edged body.
FIG. 3 b shows the cross-flow for an arrangement according to the invention with rounded edges at the openings of the body.
FIG. 4 a shows a diagrammatic front view of an arrangement according to the invention provided with spoiler element.
FIG. 4 b shows a partial diagrammatic side view of the arrangement according to FIG. 4 a.
FIG. 5 a shows a diagrammatic front view of an arrangement according to the invention, provided with spoiler element according to an alternative design.
FIG. 5 b shows a partial diagrammatic side view of the arrangement according to FIG. 5 a.
FIG. 6 shows an example of the flow across the top side of the front part of an arrangement according to the invention for storing and launching counter-measures.
DETAILED DESCRIPTION OF THE INVENTION
The aeroplane 1 shown in FIGS. 1 a and 1 b is provided on the top with an arrangement for storing and launching counter-measures, hereinafter referred to as the dispenser 2 . The dispenser has its longitudinal direction essentially coinciding with the longitudinal direction of the aeroplane. An arrow 3 designates the direction of launching from the dispenser. The letter α designates the launch angle relative to the direction or movement of the aeroplane when the counter-measures are launched obliquely forwards and upwards. The lateral angle when the counter-measures are launched with a lateral component has been indicated by β. The trajectory 4 for a launched flare 5 is indicated by a broken line. During the time from when a flare is activated for launch to when it reaches the position shown in FIGS. 1 a and 1 b , sufficient time has elapsed for the flare to have become a fully active decoy target in close proximity to the aeroplane. If this is compared with a launch directed obliquely rearwards in accordance with known principles, a very short time has elapsed at a corresponding distance of the flare from the aeroplane and an intelligent target-seeker cannot easily be misled. According to FIGS. 1 a and 1 b , the dispenser 2 is placed on a wing 6 near its attachment to the main body 7 of the aeroplane. In this context, it should be noted that the dispenser can also be placed further out on the wing 6 or directly on the main body 7 of the aeroplane.
The dispenser 2 is now described in more detail with reference to FIGS. 2 a and 2 b . The dispenser 2 comprises an elongate body 8 with a front part 9 and a rear part 10 . Between the front part and rear part there is a compartment section 11 with a number of compartments 11 . 1 , 11 . 2 , . . . 11 .n, intended to accommodate counter-measures in the form of preferably flares or chaff. The counter-measures are preferably accommodated in cartridges which can be of a type know in this field and will therefore not be discussed in detail here. The compartments can be of the same size or of different sizes and can accommodate identical or different types of counter-measures. Between each compartment there is a partition wall 12 . 1 , 12 . 2 , . . . 12 .n−1. The partition walls are inclined at an angle of, for example, 45° relative to the longitudinal direction of the body. The partition walls have a not inconsiderable thickness, preferably in the range of 10 to 30 mm, for example 15 mm. By giving the partition walls a not inconsiderable thickness, the top part 13 . 1 , 13 . 2 , . . . 13 .n−1 of each partition wall can be designed as a deflector in such a way that the partition wall at the top part finishes with an upwardly extending angle φ of the order of 15°. The compartments are delimited by the side walls 14 , 15 of the elongate body 8 and its bottom section 16 , and partition walls 12 . 1 , 12 . 2 , . . . 12 .n−1 between the compartments and partition walls 17 . 1 , 17 . 2 towards the front part 9 and rear part 10 , respectively, of the elongate body. By means of the provision of partition walls and side walls, n openings 18 . 1 , 18 . 2 , . . . 18 .n are formed.
In order to create low dynamic pressure across the openings of the compartments, the front part or nose 9 of the elongate body 8 is designed to finish towards the compartment section 11 with an upwardly extending angle γ, preferably of the order of 15°. The nose is streamlined and can be designed to follow elliptical shapes. The finish towards the compartment section creates a low dynamic pressure across the rearward openings and especially nearest to the nose. The design of the top parts of the successive partition walls 12 . 1 , 12 . 2 , . . . 12 .n−1 maintains the low dynamic pressure across the succeeding openings 18 . 2 , . . . 18 .n. The rear part 10 of the elongate body 8 is designed narrowing towards the rear in order to reduce the air resistance and it has a deflector 19 near the compartment section 11 with an essentially radial curvature.
In addition to a flow running along the length of the dispenser 2 , there are also flows running across the dispenser. In order to prevent vortices forming across the compartment openings in the manner illustrated in FIG. 3 a for an angled formation with a vortex 24 across the openings, our dispenser is designed with rounded edges 22 , 23 near the openings of the compartments. FIG. 3 b illustrates the flow across the openings in our design, and the main vortex 25 arises to the side of the dispenser. The introduction of rounded edges means that the flow is separated at a flatter angle and thereby reaches the other edge before vortices form. By lowering the vortex towards the mounting surface for the dispenser, an additional effect is that the aerodynamic load on the dispenser is reduced and the effect on the aeroplane is reduced.
To create low dynamic pressure across the openings of the dispenser 2 , FIGS. 4 a , 4 b and 5 a , 5 b show, respectively, examples of designs where the nose 9 has been provided with spoiler elements 20 . In the design according to FIGS. 4 a and 4 b , spoiler elements in the form of projecting spikes 21 are proposed, while the design according to FIGS. 5 a and 5 b proposes a projecting edge formed to follow the shape of the nose. The two proposed embodiments have been found to have a good effect on the air stream in order to create the desired low dynamic pressure across the openings 18 . 1 - 18 .n of the dispenser.
FIG. 6 shows diagrammatically how the flow across the openings 18 . 1 , 18 . 2 , . . . 18 .n of the dispenser can appear. It should be noted here that the flow which is deflected by the nose 9 to some extent drops down again towards the opening of the first compartment 18 . 1 and to a lesser extent towards the second opening 18 . 2 of the compartment. This illustrates how the risks of interfering noise being generated are greatest in the first compartment 11 . 1 , less in the second compartment 11 . 2 and much less in the succeeding compartments 11 . 3 to 11 .n.
The invention is not limited to the illustrative embodiments described above, but can be modified within the scope of the attached patent claims and the inventive concept. For example, the shape and position of the spoiler elements can be varied within wide limits. | The present invention relates to a method and an arrangement for launching counter-measures, such as flares and chaff. According to the invention, the counter-measures are launched in a direction obliquely forwards and upwards relative to the aircraft and a low dynamic pressure is created across the dispenser's launch openings. The arrangement comprises compartments for counter-measures which are provided with openings and are intended for launching the counter-measures in a direction obliquely forwards and upwards relative to the aircraft. The invention increases the possibilities of releasing a target and reduces the noise levels of the sounds which can occur in emptied compartments. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a lubrication system of linear guideway, and more particularly to a lubrication system of linear guideway with three-dimensional (3D) oil route for enabling oil to flow in a 3D manner into respective rolling ball return ways to lubricate rolling balls, and the problem of oil leakage can be prevented.
[0003] 2. Description of the Prior Arts
[0004] Most of machines are equipped with linear guiding structure, linear guideway is one of the linear guiding structures, and the rolling balls of the linear guideway should be well lubricated, then it can run smoothly and it service life can be maintained.
[0005] Conventionally, oil-flowing route for linear guideway, as shown in FIG. 10 , has an oiling hole 61 pre-defined on the end cap 60 , on contacting surface of the end cap 60 is pre-defined with oil route 62 so as to form an oil access by incorporating with the end surface of the sliding block. Along the access, the oil is able to flow on the contacting surface of the end cap 60 , and then flow into the upper rolling ball return way 63 and the lower rolling ball return way 64 . Furthermore, the contacting surface of the end cap is normally made into a capping plate in order to save production cost. On the capping plate is defined with oil route for introducing the oil into the rolling ball return way of the end cap. According to the two above-mentioned lubricating methods, it is uneasy to evenly allot the oil to respective rolling ball return ways since the oil flow in a same surface. Such that the rolling balls in the respective rolling ball return ways are unequally lubricated, which leads to different service lives of the rolling balls, thereby the whole service life of the linear way will be shortened. Moreover, the oil route exposed on the contacting surfaces of the end cap and of the sliding block, if there is machining error or the contacting surfaces are uneven, the oil will flow out of the contacting surfaces during oil replenishment.
[0006] The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional lubrication system of linear guideway.
SUMMARY OF THE INVENTION
[0007] The primary object of the present invention is to provide a lubrication system of linear guideway capable of averagely allotting the oil to the respective rolling ball return ways of linear guideway.
[0008] The secondary object of the present invention is to provide a lubrication system of linear guideway capable of improving tightness of the oil route.
[0009] The present invention provide a new solution to solve the uneven distribution of oil of the conventional lubrication system of linear guideway, such that the lubrication system in accordance with the present invention is possessed with an ability of allotting the oil averagely.
[0010] The present invention re-design an oil route by taking into consideration of the end cap and the capping plate of the linear guideway. By taking advantage of the spatial relationship, the conventional two-dimensional (2D) oil route structure has been revised to the three-dimensional (3D) oil route structure. The present invention forms 3D spatial oil route based on the cooperation of the end cap and the capping plate so as to enable oil to flow in a 3D manner to a middle portion between upper and lower rolling ball return ways, and then the oil is distributed averagely to respective rolling ball return ways to lubricate rolling balls. Furthermore, since the oil route structure of the present invention is formed in 3D manner, and lubricating part defined on contacting surfaces of the end cap and the capping plate and not on the contacting surfaces of the end cap and of the sliding block, therefore the problem of oil leakage from the contacting surface of the end cap and of the sliding block can be prevented substantially.
[0011] On the other hand, the capping plate of the present invention is additionally provided with a special stopping structure that is used to improve tightness. The stopping structure is disposed in the oiling hole on the contacting surfaces of the end cap and of the sliding block, so as to prevent the oil leakage from the contacting surfaces of the end cap and of the sliding block, such that tightness is improved. In addition, the stopping structure is a detachable structure that allows the oil to be injection in three different directions, so as to improve its applicability.
[0012] The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which shows, for purpose of illustrations only, the preferred embodiment in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is an exploded view of a lubrication system of linear guideway in accordance with the present invention;
[0014] FIG. 2 is a perspective view of an end cap in FIG. 1 ;
[0015] FIG. 3 is a front view of the end cap in FIG. 1 ;
[0016] FIG. 4 is a rear view of the end cap in FIG. 1 ;
[0017] FIG. 5 is an assembly view of the end cap and the capping plate in accordance with the present invention;
[0018] FIG. 6 is a cross sectional view of the assembly of the end cap and the capping plate in FIG. 5 ;
[0019] FIG. 7 is a perspective view of a lubrication system with oiling holes formed at different sides thereof in accordance with the present invention;
[0020] FIG. 8 is a partial cross sectional view of FIG. 7 ;
[0021] FIG. 9 is an illustrative view of the stopping piece of the capping plate of the lubrication system in accordance with the present invention;
[0022] FIG. 10 is a cross sectional view of an end cap of conventional lubrication system of linear guideway.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] FIG. 1 is an exploded view of a lubrication system of linear guideway in accordance with the present invention. Wherein an end cap 20 and a capping plate 30 are provided at both ends of a sliding block 10 . The assembly of the end cap 20 and the capping plate 30 forms rolling ball return way provided for circulation of the rolling balls.
[0024] FIG. 2 is a perspective view of the end cap in FIG. 1 . FIG. 3 is a front view of the end cap in FIG. 1 . FIG. 4 is a rear view of the end cap in FIG. 1 . Wherein the end cap 20 has two oiling holes 21 and 24 defined on the end surface and the side surface respectively. When the oil flows into oil-flowing hole 31 of the capping plate 30 from the oiling holes 21 , since stopping piece 35 stops the flow of the oil into the end surface of the sliding block, the oil is introduced to both sides of the sliding block by guide route 32 , and then flows into oil-flowing hole 33 , and through the oil-flowing hole 33 the oil is introduced to the front surface (contacting the sliding block) of the capping plate 30 from the rear surface (contacting the end cap 20 ). After that, through the hole 34 at a center position between upper and lower rolling ball return ways (about the position of threaded hole 26 ) the oil flow back to the rear surface of the capping plate 30 that contacts the curved surface 25 of the end cap 20 , so as to supply the oil to the upper and the lower rolling ball return ways for lubricating the rolling balls properly. Furthermore, if pouring into the oiling hole 24 , the oil will flow into the oil route 22 via the oil-flowing hole 23 and then to be introduced into the oiling hole 21 , and through the same above-mentioned route the oil flows into the upper and the lower rolling ball return ways, so to lubricate the rolling balls smoothly.
[0025] FIG. 5 is an assembly view of the end cap and the capping plate in accordance with the present invention. FIG. 6 is a cross sectional view of the assembly of the end cap and the capping plate in FIG. 5 . When the oil is poured in the end cap 20 and introduced by the capping plate 30 , the oil will flow into the hole 34 beside the threaded hole 26 via the oil-flowing hole 33 . And a feed hole 25 a is formed when the capping plate 30 is assembled with the curved surface 25 of the end cap 20 , and then the oil flow into the feed hole 25 a via the hole 34 , since the feed hole 25 a is very small, the oil is able to ooze into the upper and the lower rolling ball return way by capillary action.
[0026] FIG. 7 is a perspective view of a lubrication system with oiling holes formed at different sides thereof in accordance with the present invention; FIG. 8 is a partial cross sectional view of FIG. 7 . The present invention also can pour oil via oiling hole 11 on the top surface of the sliding block 10 besides pouring into the oiling holes 21 , 24 . The oil flows through the stopping piece 35 via an access 12 after it is poured into the oiling hole 11 , and then to be introduced into the oil-flowing hole 31 and the oiling hole 21 respectively. At this moment, a screw 50 is screwed in the oiling hole 21 so as to close the oiling hole 21 . The oil will flow along the guide route 32 to the feed hole 25 a via the above-mentioned route, so as to lubricate the rolling balls in the upper and the lower rolling ball return ways.
[0027] FIG. 9 is an illustrative view of the stopping piece of the capping plate of the lubrication system in accordance with the present invention, wherein the stopping piece 35 of the capping plate 30 is installed in the oil-flowing hole 31 (on the contacting surface contacting the sliding block). The stopping piece 35 includes: annular groove 351 , cone-shape recess 352 and annular protrusions 353 . Since the thickness of the stopping piece 35 in the annular groove 351 is reduced and the hardness of the portion in the annular groove 351 is weak, it is easy for the user to separate the portion surrounded by the annular groove 351 from the capping plate 30 just by pushing the cone-shape recess 352 with a cone-shape tool 40 , so as to produce an access on the stopping piece 35 . Furthermore, an annular flange 353 is defined about the oiling hole 11 so as to improve tightness.
[0028] The lubrication system of linear guideway in accordance with the present invention has changed the oil route structure from conventional two-dimensional (2D) structure into 3D structure, so as to enable the oil to flow in a 3D manner to the middle portion between the upper and the lower rolling ball return ways, and then the oil is distributed to the respective rolling ball return ways to lubricate the rolling balls.
[0029] The lubrication system of linear guideway of the present invention has the lubricating part defined on the contacting surfaces of the end cap and of the capping plate, so as to prevent the oil leaking from the contacting surfaces of the end cap and the sliding block.
[0030] The capping plate of the present invention is additionally provided with a stopping piece used to improve tightness, and the stopping piece is designed as having detachable structure so as to improve its applicability.
[0031] While we have shown and described various embodiments in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention. | The present invention relates to the lubrication system of linear guideway. The lubrication system was the three-dimensional route that made the oil flow to a middle portion between the upper and lower rolling ball return ways, and therefore the oil can be averagely distributed to the upper and lower rolling ball return ways. Thereby it can increase the effect of lubricating the ball, and lower the frequency of oil resupply. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to:
A. A process for the preparation of pile ware utilizing a single needle bed warp knitting machine, having pile sinkers, in which during the swing-through of the guides subsequent to the underlap, into the overlap position, first the ground threads and then the left pile threads are laid to the rear of the needles, and upon these needles with separation from each other, and in which the pile sinkers during or after the swing-through are introduced in the space between the needle ground threads and the left pile threads, and stay there until the knock-over of the stitch.
B. The fabric produced thereby.
C. A warp knitting machine for the production of such pile ware, comprising a needle bar, sidewardly displaceable guide bars for ground and left pile threads and a pile sinker bar whose pile sinkers may be swung into the needle gaps for the purpose of pile production, and thus may be led into the space between the ground threads and the left pile threads. When used to describe the fabric sides, the left and right refer to the technical back and technical face, respectively.
2. Description of Related Art
Such a procedure and such a warp knitting machine having pile sinkers moveable into the needle gaps are known from DE 38 278 265 C2. The pile sinkers are provided with a separation of one needle space. The guide bars are fully charged with ground and pile threads. There is thus provided a dense pile on the left side of the fabric.
In DE 11 88 754 C, it is known to anchor the pile threads in a first working cycle by stitch formation in the fabric ground and in the subsequent working cycle to lay threads around needles not participating in the formation of the ground ware, from which they are knocked over. This leads to a fabric having a half pile density. When the pile loops are located on the left side of the fabric, the loops must be additionally mechanically raised, for example, by means of a brush arrangement.
In DE 42 23 226 C2, there is a disclosure of the production of pile ware having pile provided on both sides of the fabric. For this purpose, pile sinkers resting permanently in the needle gaps are utilized by means of which the pile loops are provided to the left side, whereas on the opposite side loops are formed with the assistance of an additional hook bar. This latter however leads to a lower production speed since in the overlap phase utilizing the hooks, the thread reserve must be formed which leads to an interval in the stitch building process. Since, because of the positioning of the pile sinkers in the needle gaps, it is only possible to consider certain lapping patterns of ground threads, for example tricot, one can only obtain higher stability by means of additional weft threads, which stretch over the entire width of the machine, which necessitate the corresponding feeding arrangements.
The purpose of the present invention is to provide a new type of warp knitted fabric having pile loops on both sides thereof.
SUMMARY OF THE INVENTION
In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a process for the preparation of pile ware from pile threads and ground threads by using a warp knitting machine. This machine has a single needle bed with a plurality of needles, a plurality of pile sinkers about half as numerous as the needles, and a plurality of guide bars each having a plurality of guides. The process includes the step of threading alternating ones of the guides for each of the guide bars, to bring only every second needle into service for stitch formation. Another step is forming left pile loops by: (A) During the swing-through of the guides subsequent to the underlap into the overlap position, laying first the ground threads and then the pile threads, to the rear of the needles, to run along the needles with separation between the ground threads and the pile threads. (B) Introducing the pile sinkers into the space between the ground threads and the pile threads, during or after the swing-through, to remain there until the knock-over of the stitch. The process also includes the step of providing pile threads and ground threads and forming right pile loops by having the pile threads: (a) overreached by the pile sinkers and laid about needles not serving for stitch formation, and then (b) knocked over.
According to another aspect of the invention, knitted fabric is provided comprising threads, including pile threads and ground threads. The pile threads are formed into pile loops on the left and right sides of the fabric using the foregoing process.
According to still another aspect of the invention, a warp knitting machine is provided for the formation of pile ware from ground threads and pile threads. This machine has a needle bed with a plurality of needles. The machine also has a plurality of laterally displaceable guide bars, each having a plurality of guides for guiding the ground threads and the pile threads. The guides for each of the guide bars is alternately threaded to bring only every second needle into service for stitch formation. Also included is a pile sinker bar having a plurality of pile sinkers about half as numerous as the needles. The sinkers are swingable between the needles for introduction into a space between the ground threads and the pile threads for the purpose of pile formation. The machine also includes a displacement means for controlling displacement of the guide bars. Also included is a control means for providing pile threads (a) in a position to be overreached by pile sinkers, and (b) that are laid, prior to knock-over, about needles that are out of service for stitch formation.
According to still another further aspect of the invention, knitted fabric is provided, comprising ground threads and pile threads formed into (a) left pile loops by pile threads on pile sinkers that overreach ground threads during knock over, and (b) right pile loops by pile threads knocked off from needles that are not in service for stitch formation.
The foregoing achieves processes, machines and fabrics having advantages over the prior art are achieved. In a preferred procedure the threads are provided to the guides in a "one full/one empty" fashion. Only every second needle serves for the formation of stitches and the number of pile sinkers equals half the number of needles. Furthermore, right pile threads are provided which are over-gripped together with the ground threads by the pile sinkers, and are not laid around the stitch forming needles and then knocked over.
In this procedure, the left pile loops are produced in the conventional manner with the assistance of pile sinkers introduced into the needle gaps. These left pile loops stand upright and can be very readily sheared, for example, for the production of velours. For the production of the right pile loops which result from the knock-over of needles not participating in stitch formation, the threads are provided "one full/one empty" to the appropriate guides and the pile sinkers are provided in a separation of double the needle spacing. A pile loop is provided to the left and to the right side in every second work cycle, with the result that, if no further steps are taken, there is provided a fabric with equal number of pile loops on the right and on the left which is desirable, for example, in toweling material. This provides a method of producing very stable pile ware.
In most cases it is desirable that the left and the right pile threads are each formed from their own pile thread system. This makes it possible to provide piles of different colors on the left and on the right.
In another alternative, the left and the right pile threads may be alternating segments of the same pile thread system. In this procedure, use is made of the fact that the left and the right pile threads only form loops in every second working cycle. By means of such a single pile system, it is possible to place the same number of pile loops on each side as with two pile thread systems.
In this connection, it is desirable that the pile system, contains a Koeper binding for the fixation of the pile loops formed by knock-over. This ensures that the right loops are not pulled back by the subsequent machine steps.
Effectively, stationary pile sinkers are arranged in alternate needle spaces and form pile in one working cycle and not in the subsequent working cycle. This can lead to a patterning through a displacement control of the pile sinkers in which, by choice, the pile loops can be formed or suppressed on the left side.
A further patterning possibility exists, in that by the displacement control of the guide bar for the left pile threads, as desired, pile loops can be formed or suppressed on the left side.
Yet another possibility exists in that by the displacement control of the guide bar for the right pile threads, at choice, pile loops can be formed or suppressed on the right side. This gives rise to a strip-formed patterning across the width of the fabric.
A patterning within the stitch row is possible in that (a) by means of jacquard control, the guides for the pile threads can form pile loops on the left side or be suppressed, and/or (b) by means of jacquard control of the guides for the right pile threads, at choice, pile loops may be formed or suppressed on the right side.
In some cases, it is desirable to provide an elastic partial weft insert thread to the ground threads. By means of such partial weft threads, the fabric is pulled together in the transverse direction so that despite the provision of threads in a "one full/one empty" manner to the appropriate guides, there is provided a high fabric density.
The procedure may be achieved by setting up a warp knitting machine described as above in the following manner: The guide bars having a thread provision of "one full/one empty" are controllable in such a manner that: (a) stitch formation only occurs on each second needle, (b) the feed mechanism for the right pile threads is provided with a control means so that the pile threads are over-gripped by the pile sinkers in order that they not be laid around the stitch forming needles and are then knocked-over, and (c) the number of pile sinkers is equal to half the number of the needles.
Preferably, the pile sinker bar is displaceable in the longitudinal direction.
It is further desirable that the guides for the left and/or the right pile threads are displaceable by one needle space by means of a jacquard control.
BRIEF DESCRIPTION OF THE DRAWINGS
The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred but nonetheless illustrative embodiments in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a schematic, side elevational view of the working area of a warp knitting machine used herein.
FIG. 2 is a schematic, plan view of the pile sinker bar of FIG. 1.
FIGS. 3 through 5 are lapping diagrams for three different pile fabrics, which can be produced in accordance with the present invention.
FIGS. 6a through 6f illustrate six different embodiments for pile formation on both sides of the fabric.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a needle bar (1) having a plurality of needles (2) and the hooks (3) corresponding thereto. A slider bar (4) carries a plurality of slides (5) to close the hook space. In place thereof, there may also be employed lace needles, tongue needles or the like. A further bar (6) carries the closing knock-over sinkers (7). There are provided four guide bars L1, L2, L3 and L4 with corresponding guides (8) through (11). These guides provide threads (12) through (15), which are displaceable by displacement control arrangements (16) through (19), respectively. Arrangements 17 and 19 have jacquard controls 17a and 19a for displacing guides by one needle space. Furthermore, these guides L1 through L4 are displaceable out of the illustrated underlap position into the overlap position and may swing back as illustrated by arrow (20).
A pile sinker bar (21) carries a plurality of pile sinkers (22) whose separation corresponds to two needle spaces. The pile sinker bar (21) is, as shown in FIG. 2, provided with a displacement control arrangement (23) similarly operating in the longitudinal direction, that is to say, to and fro in the direction of arrow (24). Furthermore, it is displaceable as illustrated in FIG. 1 in the direction of arrow (25), out of the illustrated position in which it is found in the needle gaps into a retracted position in which it is located outside the needle gaps and movable back thereinto. As is described in detail in DE 38 27 265 C2, this movement in the needle gaps occurs when during the swing-through into the overlap position, the threads, with separation from each other, run along the back of the needle so that the rearmost thread (15) (or the rearmost threads) are located above the pile sinker (22) and thus form a pile whereas the remaining threads are gripped under the pile sinker (22).
The lapping diagrams of FIGS. 3 through 5 are, in the usual manner, to be read from bottom to top. The needles (2) of a stitch row are indicated by dots and the pile sinkers (22) by heavy lines. The symbol "+" means the formation of a pile loop on the left side, with the assistance of a pile sinker. The symbol "x" indicates the formation of a pile loop on the right side by knock-over of a needle (2) not provided with a stitch. The designation "left pile loop" and "right pile loop" designates the pile loops on the left and the right side of the fabric, respectively. The designation "left pile thread" and "right pile thread" refers to the pile threads appropriate for the formation of the correspondingly named pile loops, and these threads may be part of the same or different systems, depending upon the specific embodiment.
In FIG. 3, only guides bars L1, L2 and L3 are in operation. The following displacement regimen applies:
______________________________________Pile Sinker Bar 21: 0-0-0 / 1-1-1 //L1: 0-0-0 / 5-5-5 // - Ground 1 empty/1 fullL2: 0-2-2 / 3-4-3 // - Loop 1 full/1 emptyL3: 1-0-0 / 0-1-1 // - Ground 1 full/1 empty______________________________________
Thus, L1 lays a first ground thread (12) in the form of a partial weft insert of threads of elastic material running over five needle spaces. L3 lays a ground thread (14) as "Franse." Only every second needle (2) is provided with a stitch. The needles (2') lying therebetween do not serve for stitch formation so that the threads laid off on them are knocked over during the next work cycle. Only a single system of pile threads (13) is laid by L2. They form, during the first working cycle, a stitch (26) and during the following work cycle, a stitch (27) which is generated on the second needle (2) over. Therebetween, there is generated a left pile loop (28), since the pile thread segment (28) is gripped upon the pile sinker (2).
Subsequently, the pile thread (13) is then stitched in by being looped around needle (2') (not participating in the stitch formation) by needle (2). This second segment (30) of pile thread (13) thus generates a pile loop (31) on the right side of the fabric by knock-over. In Segment (30), a Koeper binding is provided. This ensures that the right loop (31) is provided with a certain fixation and therefore is not pulled back by the subsequent stitch formation process. During the second work cycle, the pile threads (13) may not be grasped by the appropriate pile sinker (22). For this reason, the pile sinker bar (21) is displaced in the longitudinal direction by control arrangement (23).
Since in each working cycle there is provided a pile loop and alternating between the left and right side, there is provided a pile fabric (32) as illustrated in FIG. 6a.
The lapping diagram of FIG. 4 shows pile fabric (33) which similarly has an equal number of pile loops on the right and on the left side as in pile fabric (32). Here, the following displacement program is utilized:
______________________________________Pile Sinker Bar 21: 0-0-0 / 0-0-0 //L1: 0-0-0 / 5-5-5 // - Ground 1 full/1 emptyL2: 2-1-1 / 0-1-1 // - Right Loop 1 full/1 emptyL3: 1-0-0 / 0-1-1 // - Ground 1 empty/1 fullL4: 1-0-0 / 2-3-3 // - Left Loop 1 empty/1 full______________________________________
The ground of FIG. 4 is laid by L1 and L3 in a manner similar to that of FIG. 3. The pile sinkers (22) are, in this case, not displaceable in the longitudinal direction. This has the consequence that the left pile threads (15) laid by L4 during the change from a first stitch (26) to a second stitch (27) are laid as a pile loop (28) by means of pile sinker (22). On the other hand, during the change from stitch (27) to stitch (26), this does not take place.
L2 forms a provision arrangement of the right pile thread (13), which is stitched in the area of stitch (27) and subsequent thereto is laid about a needle (2') that does not participate in stitch formation, so that a right pile loop (31) is formed.
The embodiment of FIG. 5 shows a fabric (34) which is formed in accordance with the following displacement protocol:
______________________________________Pile Sinker Bar 21: 0-0-0 / 2-1-1 //L1: 0-0-0 / 5-5-5 // - Ground 1 full/1 emptyL2: 0-1-1 / 4-4-4 // - Right Loop 1 full/1 emptyL3: 1-0-0 / 0-1-1 // - Ground 1 empty/1 fullL4: 1-0-0 / 2-3-3 // - Left Loop 1 empty/1 full______________________________________
In this modification the pile sinkers (22) are displaced by one needle space during each work cycle. At the beginning of each second work cycle, there occurs a short withdrawal movement in which the pile sinker bar is displaced from gap (0) to gap (2) and back to gap (1). L1 again lays a ground thread (12) as a partial weft insert over five needle spaces. L3 lays a further ground thread (14) as "Franse." The right pile thread (13) laid by L2 is tied off on the one hand on needle (2) and on the other hand, is laid about the needle (2') (not participating in stitch formation), so that a right pile loop (31) results.
The left pile thread (15) laid by bar L4 is alternately stitched in by stitch forming needle (2). Since the pile sinkers (22) are moved to and fro, left loops (28) and (28') are formed during each work cycle. The illustrated movement of the pile sinker bar leads thereto in that it operates as a hold-down sinker, which holds down the right loop formed by L2, so that this right loop cannot be pulled onto the technically left side of the fabric.
The corresponding pile ware (34) is illustrated in FIG. 6b.
The thus produced pile loops (28) and (28') may be readily sheared so that a pile fabric (35) is provided which has velour on one side and on the other side, right pile loops (31). This sheared product is illustrated in FIG. 6c.
FIG. 6d shows a pile fabric segment (37), that only carries left pile loops (28). Here, the right pile loops are suppressed in that the control arrangement (19) so displaces the guide bar L4, that the pile threads (15) are only laid off on needles (2), which serve for stitch formation.
FIG. 6e shows a pile fabric segment (38) which has only right pile loops (31), that is, a situation in which the left pile loops are suppressed. This occurs either when guide bar L2 is displaced by control arrangement (16), or pile sinker bar (21) is displaced by control arrangement (23), in such a manner that the left pile threads (15), as well as the other threads, are over-gripped by pile sinker (22). In this manner, a stripe pattern in the pile may be obtained.
FIG. 6f shows a pile fabric (39) in which a desired patterning is obtained, since the formation or suppression of individual pile loops (28) and (31) are individually prescribed. This is achieved in that the guides of pile threads (13) and/or (15) are additionally subjected to jacquard control so that the guides (9) and (11) may be individually displaced.
By utilization of a partial weft thread insert running over five needles spaces, there is provided a dimensionally stable ground fabric for the most diverse uses, for example, for bath coats. By utilizing elastic threads, there is provided a fabric of higher elasticity which can be used for clothing and sports textiles. Since different lapping possibilities can also be alternately utilized, a very large number of different pile formations are possible. The loop length, that is to say, the pile height on the left side of the goods can be obtained by utilizing different heights of pile sinkers and/or by different underlap lengths and binding of the appropriate pile thread guide bars.
Obviously, many 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. | A process and machine for the preparation of pile ware uses a single needle bedded warp knitting machine, having pile sinkers. During the swing-through of the guides subsequent to the underlap into the overlap position, first the ground threads and then the left pile threads, are laid to the rear of the needles, and run along these, with separation from each other. The pile sinkers are introduced into the space between the ground threads and the left pile threads, during or after the swing-through, and stay there until the knock-over of the stitch. The threads are provided to the guide bars in a one full/one empty order, only every second needle serving for stitch formation. The number of pile sinkers equals half of the number of needles. Right pile threads are provided which are overreached by the pile sinkers together with the ground threads laid about needles not serving for stitch formation and are then knocked over. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates generally to synthetic resins and in particular to fluorinated epoxy resins.
The terminology pertaining to epoxy resins is varied. The term "epoxy" refers to the small ring grouping ##STR1## "Resin" refers to a number of physical properties of a material generally related to amorphous, sticky, soft, semifluid. Often an epoxy resin is prepared by co-polymerizing an epoxy monomer with another monomer termed a "curing agent." Hence the term "epoxy resin" may be used to designate the epoxy component only, the epoxy-curing agent mixture before reaction, or the final polymer that results from the reaction. The term "fluorinated epoxy resin" does not mean that any of the components are actually reacted with fluorine or fluorinating agents except at the early precursor stages, but simply means the product resulting from the reaction of fluorinated materials. The term "catalyst" is used in the conventional sense, i.e., a material present in a small amount which alters the speed of reaction.
Highly fluorinated epoxy resins, on account of their superior strength, stability, and low surface energy, are extremely important today and are becoming even more important with the increasing need for paints, coatings, adhesives, and structures for harsh environments. Difficulties in the manufacture and use of these compounds, especially the resins prepared from highly fluorinated diglycidyl ethers, are caused by the known curing agents. The curing agents used in synthesizing epoxy resins are usually dianhydrides, e.g., pyromellitic dianhydride and amines, e.g. dimethylaminoethane. The defects associated with dianhydride curing agents are high melting points, e.g., the melting point of pyromellitic dianhydride is 286° C., very unaggressive reaction behavior with these epoxies, and a reduction of the fluorine content of the resin in comparison with the fluorinated epoxy monomer. While the amine curing agents react more readily, these compounds are not better in regards to the other two defects and these compounds are also objectionable due to the lower thermal stability and coloring of the resulting resins. The coloring is especially objectionable for resins which are used to fabricate sight glass tubes for boilers and evaporators and other types of windows. Fluorinated amines give some improvement. However these curing agents have several disadvantages which include poor long-term chemical stability, unaggressive reaction behavior with respect to epoxies, and excessive cost factors. Attempts, until now, to prepare fluorinated anhydride curing agents have been unsuccessful.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a new class of epoxy curing agents.
Another object of this invention is to provide epoxy resins with greater fluorine content.
Another object of this invention is to provide transparent fluorinated epoxy resins.
A further object of this invention is to provide fluorinated epoxy resins with greater thermal stability.
A still further object of this invention is to provide cheaper and more reactive epoxy curing agents.
And another object of this invention is to provide a novel class of precursors of the epoxy curing agents.
These and other objects are achieved by the novel precursors and curing agents prepared by reacting polymethyl benzene with a perfluoroacetone, by oxidizing the resulting fluoro-substituted polymethyl benzene to the acid, and by heating the resulting acid to form the anhydride curing agent.
DETAILED DESCRIPTION OF THE INVENTION
The preparation of the novel acid precursors and the monoanhydride curing agents is as follows: ##STR2## wherein R and R' may be CF 3 , C 2 F 5 , or C 3 F 7 .
The following examples are given to demonstrate but not limit the above preparation. In these examples R and R' are both CF 3 .
EXAMPLE 1
(2-Hydroxyhexafluoro-2-propyl)-3,4-dimethylbenzene, I.
This compound was prepared from o-xylene and hexafluoroacetone: bp 101°-102°/20.0 mm Hg; N D 25 1.4334; lit. (1) bp 200-200.5°/760 mm Hg.
EXAMPLE 2
4-(2-Hydroxyhexafluoro-2-propyl) phthalic acid, II.
A mixture of I(80.0 g; 0.294 mole), potassium permanganate (196 g; 1.24 moles) and 0.15 N aqueous sodium hydroxide solution (3000 ml) was stirred and maintained at 90°-93° for 4 hours. The reaction mixture was cooled and filtered to remove manganese dioxide. The alkaline purple filtrate was acidified with 12 N hydrochloric acid (140 ml), decolorized with sodium sulfite, and the clear solution extracted with ether (2 × 1 1/2 lbs.). The ether extract was dried (MgSO 4 ), filtered, the filtrate diluted with toluene (200 ml) and the resulting mixture concentrated at reduced pressure to a mass of white crystals. Dispersal of the white crystals in boiling toluene, followed by filtration of the cooled dispersions led to analytical white crystals of II: 86.5 g, 88.6% yield; mp 183°-185° Anal. calcd. for C 11 H 6 F 6 O 5 : C, 39.77; H, 1.82; F, 34.31. Found: C, 39.94; H, 1.80; F, 34.46.
EXAMPLE 3 4-(2-Hydroxyhexafluoro-2-propyl) phthalic anhydride, III.
Compound II (43.00 g, 0.129 mole) was placed in a long neck flash (300 ml) and heated in a silicone bath (200° C.) for 15 minutes. The evolved water amounted to 2.30 g; Theory, 2.33 g. A short path distillation of the viscous residue gave analytical III as a viscous, supercooled liquid which gradually crystallized: 37.7 g; 92.5% yield; bp 125°/0.3 mm Hg; mp 75° C. Anal. Calcd. for C 11 H 4 F 6 O 4 : C, 42.05; H, 1.28; F, 36.28. Found: C, 41.95; H, 1.22; F, 36.36.
It is contemplated that the preparation of the novel tetra-acid can be achieved as follows: ##STR3## wherein R and R' are CF 3 or C 2 F 5 or C 3 F 7 .
The method of preparing the novel tetra-acid precursors and the dianhydride curing agents which has been used is as follows: ##STR4## wherein R and R' are CF 3 , C 2 F 5 , or C 3 F 7 .
The pentamethyl compound of the preceding process can also be used to prepare a useful precursor and curing agent. pg,8 The curing agent is actually a mixture of anhydrides which are toluene soluble. A schematic of the preparation of these compounds is as follows: ##STR5## wherein R and R' are CF 3 , C 2 F 5 , or C 3 F 7 .
The following examples are presented as specific illustrations of the above methods. In these examples R and R' are CF 3 . It is understood that the invention is not limited to these examples but is susceptible to different modifications that would be recognized by one of ordinary skill in the art.
EXAMPLE 4
2-Hydroxyhexafluoro-2-propyl durene, IV, and 2-Hydroxyhexafluoro-2-propyl pentamethylbenzene, V.
A 3-liter 3-necked flask was equipped with a magnetic stirrer, above-surface gas inlet tube, condenser (cooled with Dry-Ice-alcohol) and drying tube (Drierite). The flask was charged with 120 g durene (0.894 mole), carbon disulfide (1200 g) and aluminum chloride (9 g). Hexafluoroacetone was introduced as rapidly as possible as indicated by the reflux in the condenser (reaction temp. 20 ± 2). After 6 hours, 54 g (0.325 mole) of hexafluoroacetone had been consumed. Water (100 ml) was added. After the exotherm subsided, the resulting mixture was acidified (125 ml 2 N hydrochloric acid). The acidified mixture was strirred overnight and then filtered to remove small amounts of inorganic salts. The carbon disulfide layer was dried and the solvent evaporated to yield 166.7 g of liquid residue. The latter analyzed 57.9% unreacted durene, 23.3% IV, 7.4% pentamethylbenzene, 5.0% V, 0.8% hexamethylbenzene, together with 5.6% of unidentified higher boiling components. The resolution of this mixture by distillation posed problems because of the tendency of IV to codistill with pentamethylene benzene and for V to codistill with hexamethyl benzene. To obviate these difficulties, the mixture was first distilled from 2N sodium hydroxide solution (1500 ml). This procedure largely suppresses the distillation of the caustic-soluble IV and V but permits the ready distillation and removal of the three caustic-insoluble aromatic hydrocarbons.
Acidification (300 ml 12N hydrochloric acid) of the alkaline residue precipitated an oil. Ether extraction of the oil, followed by distillation of the ether extract led to 30.0 g analytical IV; bp 78°/10 mm Hg; lit. (1), bp 220°-223°/760 mm Hg; yield, 28.7% based on hexafluoroacetone; Anal. calcd. for C 13 H 14 F 6 0: C, 52.00, H, 4.70; F, 37.97; Found: C,51.92; H, 4.40; F, 37.73. Further distillation gave 10 g analytical V, bp 96°/10.0 mm Hg; mp, 38°-41°; yield, 9.8%; Anal. calcd. for C 14 H 16 FO; C, 53.50; H, 5.13; F, 36.27; Found: C, 53.63; H, 5.01; F, 36.34.
EXAMPLE 5
2-Hydroxyhexafluoro-2-propyl pyromellitic acid, VI.
A flask equipped with a stirrer, thermometer and condenser was charged with 12.0 g (0.40 mole) of IV, potassium permanganate (60.0 g; 0.38 mole), sodium hydroxide (16.0 g) and water (250 ml). The stirred mixture was heated to about 90° C. and maintained at this temperature for 4 hours. The resulting mixture was filtered to remove precipitated manganese dioxide. The alkaline purple filtrate was acidified (150 ml 12N hydrochloric acid) and decolorized with sodium sulfite. The resulting white precipitate was collected, extracted with ether (400 ml), the ether extract concentrated leaving a residue of 14.5 g of white crystals mp 150°-160°. Recrystallization from .05 N hydrochloric acid (450 ml) led to 12.4 g of glistening white crystals of VI, mp 155°-160° on preheated cover glass; yield, 73.8%. Anal. calcd. for C 13 H 6 F 6 O 9 : C, 37.16; H, 1.44; F, 27.13. Found: C, 37.30, H, 1.51; F, 26.90.
EXAMPLE 6
2-Hydroxyhexafluoro-2-propyl pyromellitic anhydride, VII.
Sublimation of a 8.0 g of VI at 210°-215° C. and 10.0 mm Hg leads to 6.65 g of VII; mp 125°-126°; yield, 90.1%; Anal. calcd. for C 13 H 2 F 6 O 7 : C, 40.65; H, 0.52; F, 29.68. Found: C, 40.74; H, 0.60; F, 29.42.
EXAMPLE 7
2-Hydroxyhexafluoro-2-propyl benzenepentacarboxylic acid, VIII.
A mixture of V (13.0 g, 0.041 mole), sodium hydroxide (26 g), potassium permanganate (65 g) and water (300 ml) was stirred and maintained at about 90° C. for 4 hours. The cooled reaction mixture was filtered to remove manganese dioxide. The alkaline purple filtrate is acidified (120 ml 12N hydrochloric acid) and decolorized with sodium sulfite. The resulting white precipitate was collected, recrystallized from 4N hydrochloric acid (70 ml), and dried to furnish 12.0 g of analytical VIII; mp 217°-220°; Anal. calcd. for: C 14 H 6 F 6 O 11 ; C, 36.22; H, 13.0, F, 24.56°, Found: C, 36.40; H, 1.40; F, 24.70.
EXAMPLE 8
Heating VIII (10 g) to 240°-245° (silicone bath) for 15 minutes leads to a mixture of unidentified anhydrides (8.2 g). The toluene-soluble fraction (7.3 g) (mp 204°-205°) is useful in curing fluoroepoxy resins.
Although the curing agents of the present invention are compatible and reactive with any fluorinated epoxy, the importance of these curing agents arise from their reactivity and compatibility with highly fluorinated diglycidyl ethers. Of particular importance are the diglycidyl ethers disclosed in U.S. Pat. No. 3,879,430 issued on patent application Ser. No. 397,207 filed on Sept. 13, 1973 Jacque G. O'Rear and James R. Griffith, in Griffith et al., Fluorinated Epoxy Resins in Chemtech. pg 311-16, May 1972, and in Griffith et al., Fluorinated Network Polymers in NRL Progress Report, pg. 15-27, December 1973. These disclosures are herein incorporated by reference.
The diglycidyl ethers which are most significant economically are: ##STR6##
The curing agents of this invention react with highly fluorinated epoxies in a curing agent-to-epoxy equivalence from 0.5:1.0 to 1.3:1.0 with 0.85:1.0 to 1.0:1.0 equivalence preferred. It is preferred that the reaction is catalyzed. Any of the usual epoxy catalysts may be used. The type that is most frequently used is the tertiary amine and the most frequently used tertiary amine is dimethylbenzyl amine. For the practice of the present invention the preferred catalyst is dimethylbenzyl amine in an amount from 0.3 to 3.0 weight percent of the total reactants weight. It is most preferred that the amount of catalyst is from 0.5 to 2.0 weight percent of the total reactant weight for epoxy resins prepared from highly fluorinated diglycidyl ethers. To prepare a colorless fluorinated epoxy resin, a quaternary ammonia salt, e.g., cetyl trimethyl ammonium bromide or chloride, or triphenylphosphine is used as the catalyst. The reactants are reacted initially at a temperature from 45° to 55° until gelation and then reacted at a temperature from 80° to 100° C. until the desired cure is obtained, generally in about 3 to 5 hours.
The reaction time is from 1 to 8 hours at a temperature from 110° to 135° C. For the diglycidyl ethers, the reaction time is from 1 to 5 hours at a temperature from 115° to 125° C. with 120° C. preferred with the amine catalysts.
The following examples are given as a specific illustration of a preparation of highly fluorinated epoxy resin from a hydride curing agent of this invention. It is understood that the invention is not limited by the examples.
EXAMPLE 9 ##STR7##
The reactants were reacted in a 1:1 equivalence at 120° C. for 4 hours. Dimethylbenzyl amine in an amount of 2 weight percent of the total weight of reactants was used to catalyze the polymerization.
The resulting resin was a tough, rigid solid which had the appearance of a typical epoxy. A slight reddish-brown coloration developed during the reaction. The fluorine content of the resin was nearly 48%.
EXAMPLE 10
The reactants of Example 9 were reacted at 50° C. until gelation. The reaction temperature was gradually increased to 90° C. over a time span of 30 minutes. Heating was continued for three hours. Cetyl trimethyl ammonium bromide was used as the catalyst in an amount of 2 weight percent of the total weight of reactants.
The resulting resin was similar to the resin in Example 9 except that no color was present.
As the above examples show, effective curing agents for highly fluorinated epoxy resins are provided by the present invention. Resins which are transparent, have a higher thermal stability, and have a fluorine content of almost 50% are now possible. If hexafluoroacetone is used in the synthesis, the products are economically attractive because hexafluoroacetone is relatively cheap and is readily available commercialy.
In the specification, all temperatures, weights, and volumes are in units of degrees centigrade, grams, and milliliters.
Obviously many 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. | Fluoro-anhydride curing agents for fluorinated epoxy resins, especially for highly fluorinated epoxy resins selected from the class consisting of hydroxyperfluoroalkyl phthalic anhydride, hydroxyperfluoroalkyl pyromellitic dianhydride, and mixtures thereof; a fluoro-anhydride curing agent for fluorinated epoxy resins that is the toluene-soluble mixture prepared by heating a hydroxyperfluoroalkyl benzenepentacarboxylic acid at about 240° C; precursors for all of the curing agents; and the epoxy resins prepared therefrom. | 2 |
This is a Division of application Ser. No. 08/212,865 filed on Mar. 15, 1994, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a magnetoresistive head for use in a magnetic disk apparatus, video tape recorders (VTRs), or the like, and a magnetic write/read apparatus incorporating a magnetoresistive head. More particularly, the invention relates to a magnetoresistive head which generates little Barkhausen noise, which has high sensitivity and high linear recording resolution, and which can read signals of a high S/N ratio, and to a magnetic write/read apparatus which comprises this magnetoresistive head.
2. Description of the Related Art
A magnetoresistive head (hereinafter referred to as "MR head") is attracting much attention as a next-generation reading head to replace the conventional inductive magnetic head. Among the various types of MR heads hitherto known is a shield type MR head. The shield type MR head comprises an MR element, a shield layer having high magnetic permeability, and an insulating film interposed between the element and the shield layer. It is difficult to reduce the thickness of the insulating film to a value less than a particular one. Were the film too thin, sufficient insulation between the element and the shield layer could no longer be maintained. It is therefore hard to improve the linear recording resolution of the shield type MR head.
To solve this problem, a so-called dual-element type MR head has been developed as is disclosed in Jpn. Pat. Appln. KOKOKU Publication No. 53-37204. A dual-element type MR head has a multilayer structure; it comprises two anisotropy magnetoresistive (MR) elements and an intermediate layer interposed between the elements. The intermediate layer is either a nonmagnetic insulating layer or a nonmagnetic metal layer.
The MR elements apply operation-point biases of opposite polarities in a direction perpendicular to the plane of a magnetic recording medium when sense currents of the same polarity flow through both elements in a widthwise direction of the recording tracks of the medium. Therefore, the two MR elements change in resistance in the opposite directions when exposed to signal magnetic fields of the same polarity. The resistance change in one MR element cancels out the resistance change in the other MR element. As a result, the dual-element MR head generates no output. Conversely, when the elements are exposed to signal magnetic fields of the opposite polarities, their resistances change in the same polarity. In this case, the resistances of the MR elements strengthen each other, whereby the dual-element MR head generates an output.
As may be understood from the preceding paragraph, the dual-element MR head is a reading head which performs a so-called differential operation to generate signals. Since the thickness of the intermediate layer determines the linear recording resolution, this MR head need not have a shield layer, and is therefore simple in structure. The dual-element MR head can read signals of a high S/N ratio and have high linear recording resolution, as is known in the art.
However, no techniques have been devised which can apply an effective exchange bias field to the pair of MR elements, to thereby suppress Barkhausen noise, without compounding the structure of the dual-element MR head. The dual-element MR head has yet to be reduced to practice. Thus, there has been a demand for some means which would render the dual-element MR head practical.
Recently it has been found that a multilayer film, such as a spin-valve film, which comprises two magnetic films and a nonmagnetic film interposed between the magnetic films, exhibits large magnetoresistive far more sensitive than the anisotropy magnetoresistive conventionally attained. Research is being made for the possibility of incorporating MR elements with such an enormous magnetoresistance effect, into reading heads. Nevertheless, no MR reading head has ever known which can perform a differential operation with high reliability, to reproduce signals of a high S/N ratio at high linear recording resolution.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an MR head which generates little Barkhausen noise, which has high sensitivity, high linear recording resolution and high reliability, which can read signals of a high S/N ratio, which can be manufactured easily, and which utilizes anisotropy magnetoresistance effect.
Another object of the invention is to provide a magnetic write/read apparatus which comprises this MR head.
Still another object of this invention is to provide an MR head which generates little Barkhausen noise, which has high sensitivity, high linear recording resolution and high reliability, which can read signals of a high S/N ratio, which is easy to manufacture, and which utilizes giant magnetoresistive technology.
Another object of the invention is to provide a magnetic write/read apparatus which comprises the MR head described in the preceding paragraph.
According to the present invention, there is provided a magnetoresistive head comprising:
a first anisotropic magnetoresistive film;
a second anisotropic magnetoresistive film; and
an antiferromagnetic film interposed between the first and second anisotropic magnetoresistive films.
Also, according to the invention, there is provided a magnetoresistive head comprising:
a first magnetoresistive element formed of a pair of magnetic films and a nonmagnetic film interposed between the magnetic films;
a second magnetoresistive element formed of a pair of magnetic films and a nonmagnetic film interposed between the magnetic films; and
an antiferromagnetic film interposed between the first and second magnetoresistive elements.
Further, according to a third aspect of the invention, there is provided a magnetoresistive head comprising:
a first magnetoresistive element;
a second magnetoresistive element;
a nonmagnetic intermediate film interposed between the first and second magnetoresistive elements;
a first exchange bias layer formed on a surface of the first magnetoresistive element, the surface facing away from the nonmagnetic intermediate film; and
a second exchange bias layer formed on a surface of the second magnetoresistive element, the surface facing away from the nonmagnetic intermediate film.
Further, according to a fourth aspect of the invention, there is provided a magnetic write/read apparatus equipped with a recording magnetic head for recording an information in an insulating recording medium, and a magnetoresistive head for reading the information recorded in the recording medium, said magnetoresistive head comprising:
a first anisotropic magnetoresistive film;
a second anisotropic magnetoresistive film;
an antiferromagnetic layer interposed between the first and second anisotropic magnetoresistive films.
Further, according to a fourth aspect of the invention, there is provided a magnetic write/read apparatus equipped with a perpendicular magnetic recording head for recording an information in a Co-based alloy recording medium, and a magnetoresistive head for reading the information recorded in the recording medium, said magnetoresistive head comprising:
a first anisotropic magnetoresistive film;
a second anisotropic magnetoresistive film; and
an antiferromagnetic layer interposed between the first and second anisotropic magnetoresistive films.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
FIG. 1A is a perspective view showing an MR head according to a first embodiment of this invention;
FIG. 1B is an exploded perspective view of the head shown in FIG. 1A, indicating the directions in which the layers constituting the head are magnetized;
FIG. 1C is a diagram representing the relationship between the signal magnetic field of the head shown in FIG. 1A and the resistance of the head;
FIG. 2A is a side view showing an MR head according to a second embodiment of the present invention;
FIG. 2B is an exploded perspective view of the head shown in FIG. 2A, illustrating the directions in which the layers forming the head are magnetized;
FIG. 2C is a diagram illustrating the relationship between the signal magnetic field of the head shown in FIG. 2A and the resistance of the head;
FIG. 3 is a side view showing an MR head according to a third embodiment of the present invention;
FIG. 4A is a perspective view showing an MR head according to a fourth embodiment of the present invention;
FIG. 4B is an exploded perspective view of the head shown in FIG. 4A, representing the directions in which the layers constituting the head are magnetized;
FIG. 4C is a diagram representing the relationship between the signal magnetic field of the head shown in FIG. 4A and the resistance of the head;
FIG. 5A is a perspective view showing an MR head according to a fifth embodiment of the present invention;
FIG. 5B is an exploded perspective view of the head shown in FIG. 5A, indicating the directions in which the layers constituting the head are magnetized;
FIG. 5C is a diagram representing the relationship between the signal magnetic field of the head shown in FIG. 5A and the resistance of the head;
FIG. 6 is a side view illustrating an MR head according to a sixth embodiment of the present invention;
FIG. 7A is a perspective view showing an MR head according to a seventh embodiment of this invention;
FIG. 7B is an exploded perspective view of the head shown in FIG. 7A, depicting the directions in which the layers constituting the head are magnetized;
FIG. 8A is a side view showing an MR head according to an eighth embodiment of this invention;
FIG. 8B is an exploded perspective view of the head shown in FIG. 8A, representing the directions in which the layers constituting the head are magnetized;
FIG. 9 is a sectional view showing an MR head according to a ninth embodiment of the present invention;
FIG. 10 is a perspective view showing the MR head shown in FIG. 9;
FIG. 11 is an exploded perspective view of the head shown in FIG. 9, showing the directions in which the layers constituting the head are magnetized;
FIG. 12 is a diagram representing the relationship between the signal magnetic field of the head shown in FIG. 9 and the resistance of the head;
FIG. 13 is an exploded perspective view of the MR head according to a tenth embodiment of the invention, illustrating the directions in which the layers forming this head are magnetized;
FIG. 14 is a diagram representing the relationship between the signal magnetic field of the head shown in FIG. 13 and the resistance of the head;
FIG. 15 is a sectional view showing an MR head according to an eleventh embodiment of the present invention;
FIG. 16 is a perspective view showing the MR head shown in FIG. 15;
FIG. 17 is an exploded perspective view of the head shown in FIG. 15, depicting the directions in which the layers constituting the head are magnetized;
FIG. 18 is an exploded perspective view of an MR head according to a twelfth embodiment of this invention, representing the directions in which the layers constituting the head are magnetized;
FIG. 19 is a diagram representing the relationship between the signal magnetic field of the head shown in FIG. 18 and the resistance of the head;
FIG. 20 is a perspective view showing an MR head according to a thirteenth embodiment of this invention;
FIG. 21 is an exploded perspective view of the head shown in FIG. 20, showing the directions in which the layers constituting the head are magnetized;
FIG. 22 is a diagram representing the relationship between the signal magnetic field of the head shown in FIG. 20 and the resistance of the head;
FIG. 23 is a perspective view showing an MR head according to a fourteenth embodiment of this invention; and
FIG. 24 is an exploded perspective view of the head shown in FIG. 23, representing the directions in which the layers constituting the head are magnetized;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to a first aspect of the present invention, there is provided an MR head which comprises a first MR element, a second MR element, and an antiferromagnetic film interposed between the first and second MR elements. Both MR elements can be formed of an anisotropy MR film. Alternatively, each MR element can be either a so-called spin-valve unit which comprises a pair of magnetic films and a nonmagnetic film sandwiched between the magnetic films, or an element, such as one formed of an artificial lattice film. These elements exhibit giant magnetoresistive.
The antiferromagnetic film may be made of FeMn alloy, Ni oxide, PdMn alloy, or the like. Preferably, the antiferromagnetic film is 2 to 10 nm thick. The MR element may be 5 to 10 nm thick in the case where each MR elements is formed of an anisotropic MR film, and 0.2 to 20 nm thick in the case where each MR elements is formed of a spin-valve film or an artificial lattice film.
The MR head according to the first aspect of the invention can assume one of the following alternative types:
(1) Both MR elements are anisotropic MR films. Sense currents are supplied through the MR elements, in a widthwise direction of the magnetized recording tracks of a magnetic recording medium. The antiferromagnetic film applies two bias magnetic fields of the same polarity or opposite polarities, onto the MR elements in a widthwise direction of the recording tracks of the medium.
(2) Both MR elements are anisotropy MR films. Sense currents are supplied through the MR elements, perpendicularly to the surface of a magnetic recording medium. First and second antiferromagnetic films are interposed between the MR elements, with or without a nonmagnetic film sandwiched between the antiferromagnetic films. The first antiferromagnetic film applies a first longitudinal bias magnetic field, i.e. exchange bias field in a direction perpendicular to the surface of the recording medium, onto the first MR element on the first antiferromagnetic film side. The second antiferromagnetic film applies a second longitudinal bias magnetic field of the opposite polarity to that of the first longitudinal bias magnetic field, in the same direction of that of the first longitudinal bias magnetic field, onto the second MR element. Even if the head had a single antiferromagnetic film, the longitudinal bias magnetic fields could be applied in the same manner.
(3) Both MR elements are spin-valve units, each comprising two magnetic films and a nonmagnetic film interposed between the magnetic film. Sense currents are supplied through the MR elements, in a widthwise direction of the magnetized recording tracks of a magnetic recording medium. The antiferromagnetic film applies bias magnetic fields of the same polarity or opposite polarities, onto those magnetic films of the MR elements which contact the antiferromagnetic film.
(4) Both MR elements are spin-valve units, each comprising two magnetic films and a nonmagnetic film interposed between the magnetic film. Sense currents are supplied through the MR elements, in a direction perpendicular to the surface of a magnetic recording medium. First and second antiferromagnetic films are interposed between the MR elements, with or without a nonmagnetic film sandwiched between the antiferromagnetic films. The first antiferromagnetic film applies a first longitudinal bias magnetic field in a direction perpendicular to the surface of the recording medium, onto that magnetic film of two magnetic films constituting the first MR element, which is in contact with the first an antiferromagnetic film. The second antiferromagnetic film applies a second longitudinal bias magnetic field of the opposite polarity to that of the first longitudinal bias magnetic field, in the same direction of that of the first longitudinal bias magnetic field, onto that magnetic film of two magnetic films constituting the second MR element, which is in contact with the second antiferromagnetic film. Even if the head had a single antiferromagnetic film, the longitudinal bias magnetic fields could be applied in the same way.
(5) The antiferromagnetic film is either an insulating film or a semiconductor film. A voltage is applied in a direction perpendicular to the surface of the films constituting the first and second MR elements, antiferromagnetic film. In this condition, when both MR elements receive a signal magnetic field from a magnetic recording medium, their electrical resistance changes. This change is detected in the form of a voltage change. Thus, the MR head read a signal from the recording medium.
As described above, the MR head according to the first aspect of the invention comprises a pair of MR elements and an antiferromagnetic film interposed between the MR elements. The antiferromagnetic film applies exchange bias magnetic fields i.e. longitudinal basis fields of the same polarity or opposite polarities onto the MR elements, in a widthwise direction of the track of a recording medium, and at the same time sense currents are supplied through the MR elements in the same direction, in a widthwise direction of the track of the medium. Alternatively, the antiferromagnetic film applies exchange bias magnetic fields of the same polarity or opposite polarities onto the MR elements, perpendicularly to the surface of the recording medium, and at the same time sense currents are supplied through the MR elements in the same direction, perpendicularly to the surface of the medium. Thus, when two signal magnetic fields of the same polarity are applied to the MR elements, the resistance changes in the MR elements cancel out each other. Conversely, when two signal magnetic fields of the opposite polarities are applied to the MR elements, the resistance changes in the MR elements strength each other. Namely, the MR head is of the type which performs a differential operation. The MR head does not generate Barkhausen noise, has high linear recording resolution and high sensitivity, and can read signals of a high S/N ratio from a magnetic recording medium.
In the first aspect of the present invention, a pair of MR elements located one upon the other, and an antiferromagnetic film is interposed between the MR elements. The MR elements are used as a reading head for detecting signal magnetic fields generated from the magnetized tracks of a recording medium. The antiferromagnetic film applies exchange bias magnetic fields of predetermined intensities in particular directions, onto the MR elements. The MR elements simultaneously become a single magnetic domain. Hence, the MR head generates but little Barkhausen noise.
Furthermore, when sense currents are supplied through both MR elements, in a widthwise direction of the recording tracks of a recording medium or in a direction perpendicular to the surface of the medium, two operation-point bias magnetic fields of the same polarity or opposite polarities are applied onto the MR elements, respectively, in a direction perpendicular to the surface of the recording medium or in a widthwise direction of the recording tracks thereof. These operation-point bias magnetic fields, as well as the exchange bias magnetic fields of the same polarity or opposite polarities, are applied to the MR elements. The MR elements have their resistances changed in the opposite directions when they receive signal magnetic fields of the same polarity. As a result, the MR head generates no output voltage. On the other hand, when the MR elements receive signal magnetic fields of the opposite polarities, their resistances change in the same direction, whereby the MR head performs a differential operation to generate an output voltage.
Thus, the MR head does not respond to an uniform magnetic field applied externally. Therefore, its linear recording resolution can be determined merely by setting the thickness of the antiferromagnetic film and those of the MR elements at appropriate values--without the necessity of arranging highly permeable shield layers on both sides of each MR element.
As described above, in the MR head according to the first aspect of the present invention, the antiferromagnetic film enables the MR elements to simultaneously become a single magnetic domain. Also, by virtue of the antiferromagnetic film, the MR head performs a differential operation to generate an output voltage. In addition, the linear recording resolution of the MR head can De determined merely by setting the thickness of the antiferromagnetic film at a proper value.
According to a second aspect of the present invention, there is provided a MR head which comprises a first MR element, a second MR element, an nonmagnetic film interposed between the first and second MR elements, a first exchange bias layer formed on the outer surface of the first MR element, and a second exchange bias layer formed on the outer surface of the second MR element. Due to the exchange bias layers, those components of the magnetizing direction in the MR films, which are perpendicular to the surface of a recording medium, extend parallel to each other and in the opposite directions.
Each MR element of the head according to the second aspect of the invention may either be one which is formed of, for example, an anisotropic MR film. Alternatively, it may be one which is formed of a spin-valve film or an artificial lattice film and which has a great magnetoresistance effect.
The exchange bias layers incorporated in the MR head according to the second aspect of the invention are antiferromagnetic films made of FeMn, NiO, PdMn or the like if the MR elements are anisotropic MR films. They are similar antiferromagnetic films or Co-base or Fe oxide-based films having a large coercive force, in the case where the MR elements are spin-valve films or artificial lattice films.
It is desirable that the exchange bias layers be 2 to 100 nm thick. Preferably, the MR elements have a thickness of 5 to 50 nm if they are anisotropic MR films, and a thickness of 0.2 to 20 nm if they are either spin-valve films or artificial lattice films.
In the case where each MR element is a spin-valve film comprising two magnetic films and a nonmagnetic film interposed between the magnetic films, and if each exchange bias layer is a highly coercive film, the magnetic films (i.e., the outer films) of each MR element, which is in contact with the exchange bias layer, can be usually omitted. In this case, the magnetization of the highly coercive film itself is fixed. The nonmagnetic film (i.e., the intermediate film) of each MR element may be formed of TiN, AlN, Ti, V or the like, and is preferably 1.0 to 100 nm thick.
In the MR head according to the second aspect of this invention, each exchange bias layer formed on the outer surface of one first MR element applies to the MR element an exchange bias magnetic field which extends in a predetermined direction and which has a predetermined intensity. The MR elements can thereby become a single magnetic domain. Hence, the MR head does not generate Barkhausen noise. In other words, since the MR head has a simple structure, having only two exchange bias layers formed on the outer surfaces of the MR elements, respectively, it generates no Barkhausen noise.
Since the MR elements are separated by the nonmagnetic film interposed between them, they can operate independently of each other. Moreover, the exchange bias magnetic field and two operation-point bias magnetic fields of the same polarity or opposite polarities, generated from sense currents, magnetize the magnetic films (i.e., the outer films) of each MR element or the highly coercive films (used as the exchange bias layers), such that two components of a magnetizing direction, which are perpendicular to the surface of a recording medium, extend parallel to each other and in the opposite direction, more preferably not only parallel and in the opposite direction but also in the direction in which a signal magnetic field extend. Thus, if the signal magnetic fields, which are applied to the MR elements, are of the same polarity, the resistances of the MR elements change in the opposite directions, whereby the MR head produces no output voltage. Conversely, if the signal magnetic fields are of the opposite polarities, the resistances of the MR elements change in the same direction, whereby the MR head produces an output voltage. Namely, the head performs a differential operation to generate an output voltage. In addition, since the head does not generate Barkhausen noise, it has high linear recording resolution and high sensitivity and can reproduce signals of a high S/N ratio from a magnetic recording medium.
MR heads according to various embodiments of the present invention will be described with reference to the accompanying drawings. Of these embodiments, the first to eighth embodiments pertain to the first aspect of the invention, whereas the ninth to fourteenth embodiments pertain to the second aspect of this invention.
Embodiment 1
FIG. 1A shows an MR head according to the first embodiment of the invention. As shown in FIG. 1A, the MR head comprises a first anisotropic MR element 1 (thickness: 15 nm), a second MR element 2 (thickness: 15 nm), and an antiferromagnetic film 3 (thickness: 20 nm), interposed between the MR elements 1 and 2. Both anisotropic MR elements 1 and 2 are made of Permalloy, and the antiferromagnetic film 3 is made of FeMn, NiO or the like. Electrodes 4a and 4b are connected to the anisotropic MR elements 1 and 2, respectively. Through these electrodes 4a and 4b, sense currents I S are supplied to the elements 1 and 2, flowing in a widthwise direction of the tracks of a magnetic recording medium 5a.
The anisotropic MR elements 1 and 2 oppose the magnetic recording medium 5a which travels in the direction of an arrow 5b. When a signal magnetic field generated from the recording medium 5a is applied to the MR elements 1 and 2, the electrical resistances of the elements 1 and 2 change. As a result, the voltage between the ends of either MR element changes. The change in the voltage is detected, whereby a signal is reproduced from the magnetic recording medium 5a.
As shown in FIG. 1B, the antiferromagnetic film B applies two exchange bias magnetic fields H LB of the same polarity onto the MR elements 1 and 2, respectively, in a widthwise direction of the tracks of the medium 5a, within such an area that the magnetization M may be fully rotated by the signal magnetic field. The MR elements 1 and 2 thereby become a single magnetic domain. Therefore, the MR head does not generate Barkhausen noise.
Anisotropy in a widthwise direction of the tracks of the medium 5a can be imparted to the antiferromagnetic film 3 by two alternatively methods. In the first method, the film 3 is formed on either of the MR elements 1 and 2 in a magnetic field. In the second method, a structure comprised of the elements 1 and 2 and the film 3 interposed between the elements 1 and 2 is heated to a temperature above blocking temperature of the film 3. Whichever method is employed, rendering the film 3 anisotropic, exchange magnetic fields can be applied to the MR elements 1 and 2.
when sense currents I S are supplied to the elements 1 and 2, two operation-point bias magnetic fields H DB of the opposite polarities are applied to the anisotropic MR elements 1 and 2 in a direction perpendicular to the surface of the magnetic recording medium, as shown in FIG. 1B. The magnetization M in the elements 1 and 2 extend in the opposite directions. Hence, as shown in FIG. 1C, the resistances of the MR elements 1 and 2 decreases and increases, respectively, at around the time when the intensity H of the magnetic field is zero, as can be understood from the resistance curves 6a an 6b of the elements 1 an 2 (hereinafter referred to as "MR-response curves"). Thus, the MR head shown in FIG. 1A is one which performs a differential operation. As long as the anisotropic MR elements 1 and 2 receives signal magnetic fields of the same polarity from the magnetic recording medium 5a, the resistances of the elements 1 and 2 cancel out each other, and the MR head does not generate an output voltage.
When the anisotropic MR elements 1 and 2 detect signal magnetic fields of the opposite polarities generated from the magnetic recording medium 5a, their resistances acquire the same polarity and strengthen each other. The MR head thus generates an output voltage. Thus, the head can read signals from the medium 5a with high linear recording resolution, without using highly permeable shield layers spaced apart from both sides of each MR element. To attain a sufficient linear recording resolution it suffices to change the thicknesses of both either MR elements 1 and 2 and also the the thickness of the antiferromagnetic film 3.
As indicated above, the MR head according of the first embodiment of the invention is characterized not only in that the single antiferromagnetic film interposed between the two MR elements applies exchange biases to the MR elements, making them behave as a single magnetic domain, but also in that a sufficient linear recording resolution can be attained by changing the thickness of the antiferromagnetic film to a desired value. The MR head is quite simple in structure and easy to manufacture, and can be produced with high yield.
Embodiment 2
FIG. 2A shows an MR head according to the second embodiment of the present invention. As shown in FIG. 2A, this head comprises a first anisotropic MR element 1 (thickness: 10 nm), a second anisotropic MR element 2 (thickness: 10 nm), a first antiferromagnetic film 3a (thickness: 15 nm), and a second antiferromagnetic film 3b (thickness: 15 nm). The antiferromagnetic films 3a and 3b are interposed between the elements 1 and 2, and have different blocking temperatures. Two electrodes 4a and 4b are formed on the second MR element 2. More precisely, the electrode 4b is placed on the lower end of the element 2 which, faces a magnetic recording medium 5a, and the electrode 4a is attached to the upper end of the element 2 and thus spaced apart from the electrode 4b.
In operation, senses currents are supplied to the anisotropic MR elements 1 and 2 through the electrodes 4a and 4b, flowing perpendicularly to the surface of the recording medium 5a. As the medium 5a runs in the direction of an arrow 5b, the MR elements 1 and 2 detect signal magnetic fields generated from the medium 5a. The electrical resistances of the elements 1 and 2 therefore change. The change in resistance is detected as a voltage change. Thus, the MR head read a signal from the magnetic recording medium 5a.
As shown in FIG. 2B, the first antiferromagnetic film 3a applies to the first MR element 1 an exchange bias field H LB which extends perpendicularly to the surface of the medium 5a, while the second antiferromagnetic film 3b applies to the second MR element 2 an exchange bias field H LB which is of the polarity opposite to that of the field H LB applied to the first MR element 1 and which extends in the same direction as the field H LB applied to the first MR element 1. Furthermore, two operation-point bias magnetic fields H DB of the opposite polarities, generated from the sense currents I S , are applied to the MR elements 1 and 2, respectively, in the same direction.
Thus, as shown in FIG. 2B, the magnetization M in the MR elements 1 and 2 extend at a predetermined angle to a line normal to the tracks of the recording medium 5a unless any external magnetic field is applied to the MR head. Therefore, when signal magnetic fields of the same polarity are applied from the medium 5a to the MR elements 1 and 2, the resistances of the elements 1 and 2 decreases and increases, respectively, around H of zero, as can be understood from the MR-response curves 6a an 6b of the elements 1 an 2 illustrated in FIG. 2C. As a result of this, the MR head performs a differential operation in the same way as the first embodiment (FIG. 1A), and accomplish the same advantage as the first embodiment.
To apply exchange bias magnetic fields of the opposite polarities to the first MR element 1 and the second MR element 2, respectively, it suffices to apply a magnetic field in a predetermined direction onto the elements 1 and 2 while heating both elements at a temperature higher than T 1 , and then to a magnetic field of the opposite polarity in the same direction onto the elements 1 and 2 while heating both elements at a temperature lower than T 1 and higher than T 2 , where T 1 and T 2 are the blocking temperatures of the antiferromagnetic films 3a and 3b, respectively, and T 1 >T 2 .
The antiferromagnetic films 3a an 3b may be replaced by a single antiferromagnetic layer, which may be formed in the following method. A homogeneous antiferromagnetic layer is formed, first, in a magnetic filed having a particular intensity to a predetermined thickness (e.g., 10 nm) and then, in a magnetic field of the opposite polarity. The antiferromagnetic layer thus formed functions as if it comprised of two antiferromagnetic films, to two exchange bias magnetic fields to the MR elements 1 and 2, respectively.
Embodiment 3
FIG. 3 illustrates an MR head according to the second embodiment of the present invention. As may be seen from in FIG. 3, the MR head is a modification of the second embodiment (FIG. 2A). As shown in FIG. 3, the head differs from the second embodiment in that a nonmagnetic film 7 (thickness: 10 nm) made of AlN or the like is interposed between the first antiferromagnetic film 3a (thickness: 10 nm) and the second antiferromagnetic film 3b (thickness: 10 nm). The films 3a, 7 and 3b are formed one upon another, for example in the order mentioned. To state more specifically, the first antiferromagnetic film 3a is formed in a prescribed magnetic field applied in a specific direction. The film 3a thereby attains anisotropy of that direction. Next, the nonmagnetic film 7 is formed on the first antiferromagnetic film 3a. Then, the second antiferromagnetic film 3b is formed in a magnetic field which is applied in the same direction as the magnetic field applied to form the film 3a and which is opposite in polarity to the magnetic field applied to form the film 3a. An exchange bias magnetic field is generated at the interface between the nonmagnetic film 7 and the second antiferromagnetic film 3b. Due to this exchange bias magnetic field, the second antiferromagnetic film 3a attains anisotropy which is identical in direction and opposite in polarity to the anisotropy of the first antiferromagnetic film 3a. Hence, two exchange bias magnetic fields are applied onto the pair of MR elements 1 and 2 in the same way as in the second embodiment. The MR head according to the third embodiment achieves the same advantage as the second embodiment.
Embodiment 4
FIG. 4A shows an MR head according to the fourth embodiment of the present invention. As illustrated in FIG. 4A, this MR head comprises two MR elements 1 and 2 and an antiferromagnetic layer 3 interposed between the elements 1 and 2. The first MR element 1 is a spin-valve unit formed of a magnetic film 1a (thickness: 5 nm), a nonmagnetic metal film 8a (thickness: 2.5 nm) and a magnetic film 1b (thickness: 5 nm). Similarly, the second MR element 2 is a spin-valve unit formed of a magnetic film 2a (thickness: 5 nm), a nonmagnetic metal film 8b (thickness: 2.5 nm) and a magnetic film 2b (thickness: 5 nm). The magnetic films 1a, 1b, 2a and 2b are made of CoFe, NiFe or the like, whereas the nonmagnetic metal films 8a and 8b are made of Cu or the like.
Both MR elements 1 and 2 exhibit a giant magnetoresistive effect such as spin-valve phenomenon, and are more sensitive to magnetic fields than any conventional anisotropic MR elements. The antiferromagnetic layer 3 interposed between the MR elements 1 and 2 is made of FeMn, NiO or the like.
When sense currents I S are supplied to the MR elements 1 and 2, in a widthwise direction of the tracks of a magnetic recording medium 5a, the elements 1 and 2 detect signal magnetic fields generated from the recording medium 5a. The electrical resistances of the elements 1 and 2 therefore change, changing the voltage between the ends of each MR element. The voltage changes of the elements 1 and 2 are detected, whereby the MR head reads a signal from the magnetic recording medium 5a.
As shown in FIG. 4B, the antiferromagnetic layer 3 applies two exchange bias magnetic fields H LB in a widthwise direction of the tracks of the recording medium 5a, onto the magnetic films 1a and 2a of the MR elements, respectively, which face the antiferromagnetic layer 3. These magnetic fields H LB are so intense as not to rotate or be reversed even when they receive signal magnetic fields from the medium 5a. Meanwhile, two operation-point bias magnetic fields H DB of the opposite polarities, generated by the sense currents I S , are applied in a direction perpendicular to the surface of the medium 5a, onto the magnetic films 1b and 2b of the MR-elements, respectively, which are spaced far from the antiferromagnetic layer 3.
As a result, the magnetization M in the magnetic films 1b and 2b extend at a predetermined angle to a line normal to the tracks of the recording medium 5a and are of the opposite polarities, as is illustrated in FIG. 4B. The MR head therefore performs a differential operation as shown in FIG. 4C, in the same way as the embodiments described above.
Embodiment 5
FIG. 5A shows an MR head according to the fifth embodiment of the present invention. As shown in FIG. 5A, the MR head comprises a pair of MR elements 1 and 2 and an antiferromagnetic layer interposed between the MR elements 1 and 2. The MR elements 1 and 2 are of the same type as those of the fourth embodiment (FIG. 4A) and used to detect signal magnetic fields generated from a recording medium 5a. The antiferromagnetic layer is formed as a pair of antiferromagnetic films 3a and 3b, laid one upon the other. Two electrodes 4a and 4b are formed on the second MR element 2. More precisely, the electrode 4b is placed on the lower end of the element 2 which faces a magnetic recording medium 5a, and the electrode 4a is attached to the upper end of the element 2 and thus spaced apart from the electrode 4b.
In operation, sense currents are supplied to the spin-valve MR elements 1 and 1 through the electrodes 4a and 4b, flowing perpendicularly to the surface of the recording medium 5a. As the medium 5a runs in the direction of an arrow 5b, the MR elements 1 and 2 detect signal magnetic fields generated from the medium 5a. The electrical resistances of the elements 1 and 2 therefore change. The change in resistance is detected as a voltage change. Thus, the MR head reads a signal from the magnetic recording medium 5a.
As shown in FIG. 5B, the antiferromagnetic films 3a and 3b apply two exchange bias magnetic fields H LB of the opposite polarities, perpendicularly to the surface of the medium 5a, onto the magnetic films 1a, 2a of the MR elements 1 and 2, respectively, which face the antiferromagnetic films 3a and 3b. The magnetic field H LB are so intense as not to rotate even when they receive signal magnetic fields from the medium In the meantime, two operation-point bias magnetic fields H DB of the opposite polarities, generated by the sense currents I S , are applied in a direction normal to the tracks of the medium 5a, onto the magnetic films 1b and 2b of the MR elements, respectively, which are spaced far from the antiferromagnetic films 3a and 3b.
Thus, as shown in FIG. 5B, the magnetization M in the magnetic films 1b and 2b extend, each in the same direction as the operation-point bias magnetic field H DB applied to it. Therefore, when the magnetic films 1b and 2b detect two signal magnetic fields generated from the the medium 5a, the resistances of the MR elements 1 and 2, decreases and increases, respectively, around H of zero, as can be understood from the MR-response curves 6a an 6b of the elements 1 an 2 illustrated in FIG. 5C. As a result of this, the MR head performs a differential operation in the same way, and attains the same advantage, as the embodiments described above.
Embodiment 6
FIG. 6 shows an MR head according to the sixth embodiment of this invention. As shown in FIG. 6, the MR head is a modification of the head according to the fifth embodiment (FIG. 5A). The head is different in that a nonmagnetic film 7 made of AlN or the like is interposed between the first antiferromagnetic film 3a and the second antiferromagnetic film 3b. The films 3a, 7 and 3b are formed one upon another. More specifically, as in the third embodiment (FIG. 3), the first antiferromagnetic film 3a is formed in a prescribed magnetic field applied in a particular direction, thereby attaining anisotropy of that direction. Next, the nonmagnetic film 7 is formed on the first antiferromagnetic film 3a. Then, the second antiferromagnetic film 3b is formed in a magnetic field which is applied in the same direction as the magnetic field applied to form the film 3a and which is opposite in polarity to the magnetic field applied to form the film 3a. As a result, the second antiferromagnetic film 3b attains anisotropy which is identical in direction and opposite in polarity to the anisotropy of the first antiferromagnetic film 3a. Hence, two exchange bias magnetic fields are applied onto the pair of MR elements 1 and 2 in the same way as in the fifth embodiment (FIG. 5A). The MR head according to the sixth embodiment accomplishes the same advantage as the fifth embodiment.
Embodiment 7
FIG. 7A shows an MR head according to the seventh embodiment of the present invention. This head comprises a first magnetic film 1, a second magnetic film 2, and an antiferromagnetic layer 3. The layer 3 is made of NiO or the like and interposed between the magnetic films 1 and 2. An electrode 4a is connected to the outer side of the first magnetic film 1, and an electrode 4b to the outer side of the second magnetic film 2.
In operation, a voltage is applied between the electrodes 4a and 4b. Then a tunnel current flows through the antiferromagnetic layer 3. When the magnetic films 1 and 2 receive signal magnetic fields from a magnetic recording medium 5a, the angle defined by the magnetic fluxes in the films 1 and 2 changes. The conductances of the films 1 and 2 therefore change The conductance changes are detected in the form of voltage changes, whereby the MR head reads a signal from the magnetic recording medium 5a.
As shown in FIG. 7B, the antiferromagnetic layer 3 applies exchange bias magnetic fields to the magnetic films 1 and 2. The exchange bias magnetic fields are so intense that the magnetization M in the films 1 and 2 are rotated by signal magnetic fields generated from the medium 5a. Therefore, when the first magnetic film 1 and the second magnetic film 2 receive signal magnetic fields which are identical in intensity and polarity, the MR head generates no output voltage. Conversely, when the films 1 and 2 receive signal magnetic fields which are identical in intensity and different in polarity, the MR head generates a maximum output voltage. Namely, the MR head according to the seventh embodiment performs a differential operation in the same way, and accomplish the same advantage, as the embodiments described above.
Embodiment 8
FIG. 8A shows an MR head according to the eighth embodiment of the present invention. As can be understood from FIG. 8A, the MR head is identical to the seventh embodiment shown in FIG. 7A, except for two points. First, two antiferromagnetic films 3a and 3b having different blocking temperatures are interposed between the first magnetic film 1 and the second magnetic film 2. Second, the antiferromagnetic films 3a and 3b apply two exchange bias magnetic fields of the opposite polarities to the magnetic films 1 and 2, respectively, in a widthwise direction of the tracks of a magnetic recording medium.
MR head according to the eighth embodiment operates in the same way, and achieves the same advantage, the seventh embodiment shown in FIG. 7A.
As described above, according to the first aspect of the invention there can be provided an MR head which is characterized in two respects. First, the head comprises a pair of MR elements and at least one antiferromagnetic film interposed between the MR elements. Second, the antiferromagnetic film applies two exchange bias magnetic fields of the same or opposite polarities to the MR elements, respectively, in a widthwise direction of the tracks of a magnetic recording medium, and sense currents are supplied to the MR elements in the same direction, in a widthwise direction of the tracks of the recording medium; alternatively, the antiferromagnetic film applies two exchange bias magnetic fields of the same or opposite polarities to the MR elements, respectively, in a direction perpendicular to the surface of the recording medium, and sense currents are supplied to the MR elements in the same direction, in a direction perpendicular to the surface of the recording medium Hence, the resistance changes in the MR elements cancels out each other when the MR elements receive signal magnetic fields of the same polarity, and strengthen each other when the MR elements receive signal magnetic fields of the opposite polarities.
The MR head does not generate Barkhausen noise. Moreover, it has high linear recording resolution and high sensitivity and can read signals of a high S/N ratio from a magnetic recording medium. In addition, the MR head simple in structure and easy to manufacture, and can be produced with high yield. Still further, the MR head may include elements exhibiting giant magnetoresistive, such as spin-valve units. If incorporating such elements, the MR head will read signals with higher sensitivity and at higher S/N ratio than MR head using conventional anisotropic MR elements.
The ninth to fourteenth embodiments, which pertain to the second aspect of this invention, will now be described.
Embodiment 9
An MR head according to the ninth embodiment of the present invention will be described, with reference to FIGS. 9 to 12. FIG. 9 is a sectional view illustrating the structure of the head. FIG. 10 is a perspective view, representing the positional relationship of the head and a magnetic recording medium.
As shown in FIGS. 9 and 10, the MR head comprises an intermediate nonmagnetic film 11 made of TiN and two spin-valve units 12 and 13 sandwiching the film 11 and used as a pair of MR elements. Each spin-valve unit is formed of a pair of magnetic films 14 and 16 and a nonmagnetic film 15 interposed between the magnetic films 14 and 16. The magnetic films 14 and 16 are made of Co 90 Fe 10 , and the nonmagnetic film 15 is made of Cu. The structure of the MR head is not limited to the one shown in FIG. 9. Rather, the head may have some other three-layer structures, such as Co/Cu/Co structure, Co/Ru/Co structure, Fe/Cr/Fe structure, NiFe/Cu/NiFe structure, and NiFe/Ag/NiFe structure.
An antiferromagnetic film 17 of Fe 50 Mn 50 , used as an exchange bias layer, is formed on the outer surface of the magnetic film 14 of the first spin-valve unit 12. Similarly, an antiferromagnetic film 18 of Fe 50 Mn 50 , used as an exchange bias layer, is formed on the outer surface of the magnetic film 14 of the second spin-valve unit 13. Leads 19 are connected to the antiferromagnetic film 17. Thus, the components 11, 12, 13, 17, 18 and 19 constitute the MR head according to the ninth embodiment of the present invention.
The MR head has been produced by forming, on a substrate 50, the antiferromagnetic film 18 (thickness: 15 nm), the magnetic film 14 (thickness: 5 nm), the nonmagnetic film 15 (thickness: 2 nm), the magnetic film 16 (thickness: 5 nm), the intermediate nonmagnetic film 11 (thickness: 30 nm) the magnetic film 16 (thickness: 5 nm), the nonmagnetic film 15 (thickness: 2 nm), the magnetic film 14 (thickness 5 nm) and the antiferromagnetic film 17 (thickness: 15 nm)--one upon another, in the order mentioned. These films may be formed by means of ion-beam sputtering, vapor deposition, or the like. As is seen from FIG. 10, the MR head has shape anisotropy, extending longer along the track width of a magnetic recording medium 20 than along the signal magnetic field generated from the medium 20. The structure formed of the films 11 to 18 can, therefore, be patterned by ordinary process comprising various steps such as resist coating, exposure, development and ion-milling. To prevent the structure from being corroded during the patterning process, it would be desirable that a protective layer be formed on the uppermost film of the structure, i.e., the antiferromagnetic film 17.
In operation, sense currents I S are supplied to the MR head, flowing in the direction of an arrow namely in a widthwise direction off the tracks of the recording medium 20. Signal magnetic fields are applied from the medium 20 along in the direction of an arrow B 1 , namely in a direction parallel to the interfaces among the films of the MR head and perpendicular to the sense currents I S .
The directions in which the films of the MR head are magnetized will be explained, with reference to FIG. 11 which is an exploded perspective view of the MR head. As indicated above, the sense currents I S flow through the MR head, in a widthwise direction of the tracks of the magnetic recording medium 20. Thus, magnetic anisotropies a 1 and a 2 are imparted to the antiferromagnetic films 17 and 18, both made of Fe 50 Mn 50 . The magnetic films 14, which are made of Co 90 Fe 10 and exchange-coupled to the antiferromagnetic films 17 and 18, respectively, are fixedly magnetized and thus have magnetic anisotropies b 1 and b 2 , respectively. The magnetic anisotropy b 1 is identical to the magnetic anisotropy a 1 of the antiferromagnetic film 17, and the magnetic anisotropy b 2 is identical to the magnetic anisotropy a 2 of the antiferromagnetic film 18. Thus, the antiferromagnetic films 17 and 18, which are the outermost layers of the head, are magnetized in the opposite directions, and the magnetic films 14 of the spin-valve units 12 and 13 are magnetized in the opposite directions.
Magnetic anisotropy can be imparted to each film by applying an external DC magnetic field onto the film being formed in the direction desired for the magnetic anisotropy. The anisotropy can easily be changed in direction, by altering the direction in which to apply the external DC magnetic field. An alternative method of changing the magnetic anisotropy is to change the blocking temperatures of both antiferromagnetic films 17 and 18 by heating these films 17 and 18 in a magnetic field. To be more precise, the film 17 is first heated in a magnetic field to temperature T lower than its blocking temperature T 1 , thus acquiring magnetic anisotropy of a desired direction. Next, the film 18 is first heated in a magnetic field to temperature T somewhere between temperature T 1 and the blocking temperature T 2 of the film 18, which is higher than temperature T 1 , thereby acquiring magnetic anisotropy of a direction different from that of the anisotropy of the film 17.
Each magnetic film 16 made of Co 90 Fe 10 , interposed between the nonmagnetic films 11 and 15 which are made of TiN and Cu, respectively, has a magnetization-easy axis which extends in the direction of supplying sense currents I S . The film 16 of the first spin-valve unit 12 is magnetized in the direction of an arrow c 1 , and the film 16 of the second spin-valve unit 13 is magnetized in the direction of an arrow c 2 . The magnetic films 14, made of Co 90 Fe 10 and contacting the Fe 50 Mn 50 antiferromagnetic films 17 and 18, are fixedly magnetized by exchange bias magnetic fields. Thus, it is only the Co 90 Fe 10 magnetic films 16 which are magnetized in response to a signal magnetic field H SIG applied externally.
As illustrated in FIG. 11, the signal magnetic field H SIG extends parallel to the interfaces among the films of the MR head and perpendicularly to the sense currents I S . Therefore, the magnetic films 16 made of Co 90 Fe 10 are magnetized in the directions of arrows d 1 and d 2 when they receive signal magnetic fields of the same polarity. That is, the magnetization directions in the films 16 change.
FIG. 12 is a diagram representing how the resistances of the spin-valve units 12 and 13 depend on signal magnetic fields H SIG , and also explaining how the MR head shown in FIG. 9 performs a differential operation.
When signal magnetic fields of the same polarity are applied to the spin-valve units 12 and 13, the resistance of one spin-valve unit increases, while the resistance of the other spin-valve unit decreases as shown in FIG. 12. As a result, the resistances of the units 12 and 13 cancel out each other, and no resistance change occurs in the MR head. On the other hand, signal magnetic fields of the opposite polarities are applied to the spin-valve units 12 and 13, the resistances of both spin-valve units are either high or low. In this case, the resistances of the units 12 and 13 strengthen each other, and a large resistance change occurs in the MR head. Thus, the MR head according to the ninth embodiment works as a reading head which performs an differential operation on a magnetization-reversed region of the recording medium 20.
The Fe 50 Mn 50 antiferromagnetic films 17 and 18 apply two exchange bias magnetic fields onto the outer Co 90 Fe 10 magnetic films of the spin-valve units 12 end 13, respectively. Furthermore, the Co 90 Fe 10 magnetic films 16 of both spin-valve units 12 and 13 have each magnetic anisotropy in a widthwise direction of the tracks of the magnetic recording medium 20. The spin-valve units 12 and 13 become a single magnetic domain, generating no Barkhausen noise. Since the MR head performs a differential operation, it has high linear recording resolution, high sensitivity, high S/N ratio, and high reliability.
Embodiment 10
FIG. 13 is an exploded perspective view shown an MR head according to the tenth embodiment of the present invention. As shown in FIG. 13, this MR head is identical to the ninth embodiment (FIG. 9) as regards the multilayer structure. Magnetic anisotropies a 3 and b 3 of the same direction are imparted to the antiferromagnetic layer 17 and the magnetic layer 14 of the first spin-valve unit 12, respectively. Magnetic anisotropies a 4 and b 4 , which are opposite in direction to the magnetic anisotropies a 3 and b 3 , are imparted to the antiferromagnetic layer 18 and the magnetic layer 14 of the second spin-valve unit 13, respectively. In other words, the films 14, 17 and 18 are fixedly magnetized. Signal magnetic fields H SIG are applied to the MR head, in a direction parallel to the magnetic anisotropies of the films 14, 17 and 18, whereas sense currents I S are supplied in a direction perpendicular thereto. The magnetic anisotropy imparted to the Co 90 Fe 10 magnetic film 16 of each spin-valve unit, which is shielded from the exchange bias magnetic fields generated from the antiferromagnetic films 17 and 18, differ by 90° from the magnetic anisotropy of the corresponding magnetic films 16 incorporated in the ninth embodiment. Namely, the magnetic films 16 of both spin-valve units 12 and 13 have magnetic anisotropies which are perpendicular to the flowing direction of the sense currents I S and which are paralled and opposite to each other. More specifically, the magnetic film 16 of the first spin-valve unit 12 has upward magnetic anisotropy c 3 which is perpendicular to the sense currents I S , and the magnetic film 16 of the second spin-valve unit 13 has downward magnetic anisotropy c 4 which is perpendicular to the sense currents I S .
FIG. 14 illustrates the relationship between the signal magnetic fields H SIG applied to the MR head and the electric resistances of the spin-valve units 12 and 13. With reference to FIG. 14, the differential operation the MR head performs will be explained.
The resistances R of the spin-valve units 12 and 13 have hysteresis shown in FIG. 14, varying in accordance with the intensity of the signal magnetic field which changes between H SIG +H c and H SIG -H c . This is because the Co 90 Fe 10 magnetic films 16 undergo magnetization reversal. To be more precise, the first spin-valve unit 12 has hysteresis indicated by a broken-line arrows, and the second spin-valve unit 13 has hysteresis indicated by a solid-line arrows. Due to the sense currents I S , the hysteresis of the first spin-valve unit 12 shifts to the positive side, whereas the hysteresis of the second spin-valve unit 12 shifts to the negative side. When signal magnetic fields of the same polarity, each having an intensity over+H c , are applied to the spin-valve units 12 and 13, the electric resistance of the unit 12 decreases, whereas that of the unit 13 increases. The resistances of the units 12 and 13 therefore cancel out each other, whereby no resistance change takes place in the MR head. Conversely, when signal magnetic fields of the opposite polarities are applied to the spin-valve units 12 and 13, the resistances of the units 12 and 13 either increase or decrease. In this case, the resistances of the units 12 and 13 strengthen each other, and a resistance change occurs in the MR head. Thus, the MR head performs a differential operation on the signal magnetic fields.
The head has high linear recording resolution, high sensitivity, high S/N ratio, and high reliability.
Embodiment 11
As may be understood from FIG. 15, the MR head according to the eleventh embodiment of this invention has the same multilayer structure as the ninth embodiment (FIG. 9). However, it is so positioned with respect to a magnetic recording medium 20 such that, as shown in FIG. 16, sense currents I S and a signal magnetic field H SIG are parallel and opposite, as indicated by arrows A 2 and B 2 . That is to say, the signal magnetic field H SIG is applied in parallel to the sense currents I S .
FIG. 17 is an exploded perspective view of the head shown in FIG. 15, depicting the directions in which the layers constituting the head are magnetized. As is seen from FIG. 17, the sense currents I S flow in the direction of an arrow A 2 . The Fe 50 Mn 50 antiferromagnetic films 17 and 18 and the Co 90 Fe 10 magnetic films 14, both exchange-coupled to the films 17 and 18, are given anisotropies of the direction in which the sense currents I S have been supplied. At this time, in the first spin-valve unit 12 an exchange bias magnetic field is applied in the direction in which the sense currents I S are flowing, thus fixedly magnetizing the Co 90 Fe 10 magnetic film 14 in the direction of an arrow b 5 --that is, along a line perpendicular to the surface of the medium 20. In the second spin-valve unit 13, an exchange bias magnetic field is applied in the direction opposite to the direction in which the sense currents I S are flowing, thus fixedly magnetizing the Co 90 Fe 10 magnetic film 14 in the direction of an arrow b 6 --that is, in the direction opposite to the direction in which the film 14 of the first spin-valve unit 12 is magnetized.
The magnetized direction of the Co 90 Fe 10 magnetic film 16 of each spin-valve unit is identical to the direction in which the magnetic field generated by the sense currents I s are applied to the unit. More precisely, the film 16 of the first spin-valve unit 12 is magnetized downwards, in the direction of an arrow c 5 , whereas the film 16 of the second spin-valve unit 13 is magnetized upwards, in the direction of an arrow c 6 . As shown in FIG. 17, a signal magnetic field H SIG is parallel to the interfaces among the films of the MR head and also to the sense currents I. Thus, when two signal magnetic fields of the same polarity are applied to the spin-valve units 12 and 13 which are magnetically isolated by the TiN nonmagnetic film 11, magnetization reversals will occur in the Co 90 Fe 10 magnetic films 16 as indicated by, for example, arrows d 3 and d 4 in FIG. 17.
The resistances of the spin-valve units 12 and 13 depend on the signal magnetic fields as shown in FIG. 12--that is, in the same manner as the resistances of the units 12 and 13 of the ninth embodiment (FIG. 9). More specifically, when signal magnetic fields of the same polarity are applied to the units 12 and 13, the resistance of these units decreases, whereas that of the unit 13 increases. The resistances of the units 12 and 13 therefore cancel out each other, whereby no resistance change takes place in the MR head. Conversely, when signal magnetic fields of the opposite polarities are applied to the units 12 and 13, the resistances of these units either increase or decrease. In this case, the resistances of the units 12 and 13 strengthen each other, and a resistance change occurs in the MR head. Thus, the MR head performs a differential operation on the signal magnetic fields.
The MR head according to the eleventh embodiment also has high linear recording resolution, high sensitivity, high S/N ratio, and high reliability.
Embodiment 12
The MR head according to the twelfth embodiment of the invention, which has the same multilayer structure as the eleventh embodiment, will be described with reference to FIG. 18. As shown in FIG. 18, the sense currents I S are supplied in the same direction, and the signal magnetic field is applied in the same direction, as in the eleventh embodiment. In the second spin-valve unit 13, the Fe 50 Mn 50 antiferromagnetic film 18 applies an exchange bias magnetic field in the direction of an arrow a 8 , which is identical to the direction of supplying the sense currents I S , and the Co 90 Fe 10 magnetic film 16 is magnetized in the direction of an arrow b 8 which is also identical to the direction of supplying the sense currents I S . In the first spin-valve unit 12, the Fe 50 Mn 50 antiferromagnetic film 18 applies an exchange bias magnetic field in the direction of an arrow a 7 , which is opposite to the direction of supplying the sense currents I S , and the Co 90 Fe 10 magnetic film 14 is magnetized in the direction of an arrow b 7 which is also opposite to the direction of supplying the sense currents I S . The Co 90 Fe 10 magnetic films 16 of both spin-valve units 12 and 13 are magnetized in the same direction as the flowing direction of the sense currents I S .
The differential operation of the MR head will be explained, with reference to FIG. 19 which represents the relationship between the intensity of the signal magnetic field H SIG and the electric resistance R of the MR head.
When a signal magnetic field is applied to the MR head, the resistances of the spin-valve units 12 and 13 change as shown in FIG. 19. More precisely, the spin-valve units 12 and 13 have resistance hystereses indicated by broken-line arrows and solid-line arrows, respectively. Their resistances R changes as the intensity of the signal magnetic field which varies between H SIG +H c and H SIG -H c . When signal magnetic fields of the same polarity, each having an intensity over+H c , are applied to the spin-valve units 12 and 13, the resistance R of the unit 12 decreases, whereas the resistance R of the unit 13 increases. The resistances R of the units 12 and 13 therefore cancel out each other, whereby no resistance change takes place in the MR head. Conversely, when signal magnetic fields of the opposite polarities are applied to the spin-valve units 12 and 13, the resistances R of the units 12 and 13 either increase or decrease. In this case, the resistances R of the units 12 and 13 strengthen each other, and a resistance change occurs in the MR head. Thus, the MR head performs a differential operation on the signal magnetic fields.
Like the ninth embodiment, the MR therefore does not generate Barkhausen noise. It has high linear recording resolution, high sensitivity, high S/N ratio, and high reliability.
Embodiment 13.
The MR head according to the thirteenth embodiment of this invention will now be described, with reference to FIGS. 20, 21 and 22.
FIG. 20 shows the positional relationship between the MR head and a magnetic recording medium 20. As can been seen from FIG. 20, the head comprises two magnetic films 21 and 22 made of Ni 80 Fe 20 (hereinafter referred to as "Permalloy"), an intermediate nonmagnetic film 11 made of TiN and interposed between the magnetic films 21 and 22, and two antiferromagnetic films 17 and 18 made of Fe 50 Mn 50 and formed on the outer surfaces of the Permalloy magnetic films 21 and 22, respectively. Two electrodes 19 are connected to the first Fe 50 Mn 50 antiferromagnetic film 17. More specifically, the head has been produced by forming, on a substrate (not shown), the Fe 50 Mn 50 antiferromagnetic film 18 (thickness: 15 nm), the Permalloy magnetic film 22 (thickness: 25 nm), the TiN intermediate nonmagnetic film 11 (thickness: 30 nm), the Permalloy magnetic film 21 (thickness: 25 nm), and the Fe 50 Mn 50 antiferromagnetic film 17 (thickness: 15 nm)--one upon another, in the order mentioned. As shown in FIG. 20, sense currents I S flow in the direction of an arrow A 3 , in a widthwise direction of the tracks of the recording medium 20, while signal magnetic fields H SIG generated from the medium 20 are applied in the direction of an arrow B 3 , in a direction parallel to the interfaces of the films and perpendicular to the sense currents I S .
FIG. 21 is an exploded perspective view of the MR head shown in FIG. 20. As seen from FIG. 20, the Fe 50 Mn 50 antiferromagnetic films 17 and 18 apply exchange bias magnetic fields H T to the Permalloy magnetic films 21 and 22, respectively, which contact the films 17 an 18. These magnetic fields H T extend parallel to the direction in which the sense currents flow, as is indicated by arrows e 1 and e 2 . Two operation-point bias magnetic fields H B , generated by the sense currents I S , are applied onto the Permalloy films 21 and 22 magnetically isolated by the TiN intermediate nonmagnetic film 11, in the directions of arrows f 1 and f 2 . Thus, a composite bias magnetic field extending slantwise and downwards is applied to the Permalloy magnetic film 21, whereas a composite bias magnetic field extending slantwise and upwards is applied to the Permalloy magnetic film 22. As a result of this, the magnetic films 21 and 22 are magnetized fixedly in the directions of arrows g 1 and g 2 , respectively.
FIG. 22 is a diagram representing the relationship between the signal magnetic fields applied to the MR head, on the one hand, and the resistance R of the head, on the other. With reference to FIG. 22, it will be explained how the MR head performs an differential operation.
When signal magnetic fields of the same polarity are applied to the MR head, the resistance of the Permalloy film 22 decreases, whereas the resistance of the Permalloy film 21 first increases and then decreases. Hence, unless the signal magnetic fields are excessively intense, the resistances of the magnetic films 21 and 22 cancel out each other, whereby no resistance change takes place in the MR head. On the other hand, when signal magnetic fields of the opposite polarities are applied to the MR head, the resistances of the magnetic films 21 and 22 either increase or decrease. In this case, the resistances of the magnetic films 21 and 22 strengthen each other, and a resistance change occurs in the MR head. Thus, the MR head performs a differential operation to generate an output voltage.
Since the Fe 50 Mn 50 antiferromagnetic films 17 and 18 apply exchange bias magnetic fields onto the Permalloy magnetic films 21 and 22, the films 21 and 22 become a single magnetic domain, generating no Barkhausen noise. Moreover, the MR head, which performs a differential operation, has high linear recording resolution, high sensitivity, high S/N ratio, and high reliability.
Embodiment 14
The MR head according to the fourteenth embodiment of this invention will be described, with reference to FIGS. 23 and 24. As can be understood from FIG. 23, this MR head is identical in structure to the thirteenth embodiment (FIG. 20). In use, the MR head is positioned with respect to a magnetic recording medium such that signal magnetic fields H SIG generated from the medium 20 are applied in the direction of an arrow B 4 , that is, parallel to sense currents I S flowing in the direction of an arrow A 4 .
With reference to FIG. 24 which is an exploded perspective view of the MR head, the directions in which the films of the head are magnetized will be explained. The Fe 50 Mn 50 antiferromagnetic film 17 applies to the Permalloy film 21 an exchange bias magnetic field H T which extends in the same direction as the sense current I S , as indicated by an arrow e 3 . On the other hand, the Fe 50 Mn 50 antiferromagnetic film 18 applies to the Permalloy film 22 an exchange bias magnetic field H T which extends in the opposite direction to the sense current I S , as indicated by an arrow e 4 . Two operation-point bias magnetic fields H B , generated by the sense currents I S , are applied onto the Permalloy films 21 and 22 magnetically isolated by the TiN intermediate nonmagnetic film 11, in the directions of arrows f 3 and f 4 . As a result, two composite magnetic fields are applied onto the magnetic films 21 and 22, respectively, in the directions of arrows g 3 and g 4 , whereby the magnetic films 21 and 22 are fixedly magnetized.
When signal magnetic fields H SIG are applied to the MR head in this condition, the resistance changes will take place in the Permalloy magnetic films 21 and 22 in the same way as illustrated in FIG. 22. Therefore, the MR head performs a differential operation to generate an output voltage, and has high linear recording resolution, high sensitivity, high S/N ratio, and high reliability.
As has been described, the present invention can provide an MR head which is simple in structure, which generates but little Barkhausen noise, and which can perform a differential operation. The MR head, therefore, has high sensitivity, high S/N ratio, high linear recording resolution and high reliability, and possesses a great industrial value.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, and representative devices, shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. | A magnetoresistive head includes an antiferromagnetic portion interposed between first and second spin-valve units. Sense current supply directions through the first and second spin-valve units are perpendicular to a head facing surface of a magnetic recording medium. The first spin-valve unit is formed of a first inner magnetic film, a first outer magnetic film and a nonmagnetic film interposed between and in direct physical contact with the first inner magnetic film and the first outer magnetic film. The second spin-valve unit is formed of a second inner magnetic film, a second outer magnetic film and a nonmagnetic film interposed between and in direct physical contact with the second inner magnetic film and the second outer magnetic film. The antiferromagnetic portion is formed of a first antiferromagnetic sublayer and a second antiferromagnetic sublayer laminated on the first antiferromagnetic sublayer. The first antiferromagnetic sublayer is in contact with the first inner magnetic film to apply a first exchange bias magnetic field to the first inner magnetic film in a direction perpendicular to the head facing surface of the magnetic recording medium. The second antiferromagnetic sublayer is in contact with the second inner magnetic film to apply a second exchange bias magnetic field to the second inner magnetic film in a direction perpendicular to the surface of the magnetic recording medium. The second exchange bias magnetic field has a polarity opposite to that of the first exchange bias magnetic field. | 6 |
CLAIM OF PRIORITY
[0001] This application claims priority from Japanese Patent Application Nos. 2003-186932, 2003-187608, 2003-187789, 2003-187560 and 2003-187936, each titled “Retractable Roof Fixing Apparatus” and filed on Jun. 30, 2003, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to roof fixing apparatus, and more particularly, to a roof fixing apparatus for fixing a retractable roof provided on a convertible automotive vehicle.
[0004] 2. Description of Related Art
[0005] Conventionally, a convertible automotive vehicle is provided with a retractable roof to cover the interior of the vehicle, so as to provide protection against cold weather and rain. Typically, such a retractable roof is mounted at a base to a rear part of the body of the vehicle, with a front end of the roof moved to extend and to retract the roof. If left exposed when not in use, however, the roof not only impedes the rear view of the operator of the vehicle but is also unsightly, susceptible to dust and dirt, and may experience color fading.
[0006] As a result, the retractable roof is stored within a rear portion of the body of the vehicle when not in use and covered by a storage cover. To be used, the cover is lifted and the roof is extended.
[0007] Accordingly, after the retractable roof is separated from the vehicle and released from storage, it is desirable to close the storage cover, set the roof on top of the cover and then fix the base of the roof to the vehicle body by a lock device.
[0008] As automotive vehicle lock devices, there is known a device in which a striker is mounted to a door or the body of the vehicle while a latch is mounted oppositely, so that when the door contacts the body the impact of the contact rotates the latch, causing the latch to engage the striker and thus secure the door. Such an arrangement is disclosed, for example, in Japanese Laid-Open Patent Publication Nos. 12-27511 and 2001-193328.
[0009] In the conventional lock device described above, a length from a point at which the striker contacts the latch to a point at which the latch fully engages the striker and the door is closed coincides with a distance through which a notch that engages the striker moves with the rotation of the latch, and is no more than approximately 5-7 mm.
[0010] In the case of a door lock device that fixes the door in a state in which a hard, heavy door contacts an edge part of an opening in the vehicle body, such distance as described above are sufficient. However, when fixing a retractable roof to the vehicle body, such minimal distances create a risk that vibration during operation of the vehicle might open a gap between the roof and the body.
SUMMARY OF THE INVENTION
[0011] Accordingly, the present invention is conceived as a response to the above-described disadvantage of the conventional art, and has as an object to provide a retractable roof fixing apparatus that can snugly draw the roof to a vehicle body and fix the roof to the body by greatly retracting a striker.
[0012] Another object of the present invention is to provide a retractable roof fixing apparatus that securely draws the roof to a vehicle body and fixes the roof to the body by driving a motor that rotates a cam that greatly retracts a striker engaging a latch.
[0013] According to the retractable roof fixing apparatus described above, the retractable roof fixing apparatus can limit an increase in load on the motor even when a lifting force applied from the roof to the latch approaches a retraction limit position.
[0014] Another and further object of the present invention is to provide a retractable roof fixing apparatus that can fully draw the roof to a vehicle body and securely fix the base end of the roof to the body by greatly retracting the striker engaging the latch, in which the slide plate supporting the latch slides stably.
[0015] Still another and further object of the present invention is to provide a retractable roof fixing apparatus that can fully draw the roof to a vehicle body and securely fix the base end of the roof to the body by greatly retracting the striker engaging the latch, and moreover, that prevents a geared cable that connects the motor and the cam from buckling from the reaction when the striker is released.
[0016] Still yet another and further object of the present invention is to provide a retractable roof fixing apparatus that can fully draw the roof to a vehicle body and securely fix the base end of the roof to the body by greatly retracting the striker engaging the latch, with the rotation of the cam is restricted so as to securely engage the latch with the striker as well as to hold the striker at a retracted position when the slide plate supporting the latch is at a top dead center position or a bottom dead center position.
[0017] In order to achieve the above-described objects of the present invention, according to a first aspect of the invention there is provided a retractable roof fixing apparatus comprising:
[0018] a striker fixed on a roof;
[0019] a base plate fixed on a body of a vehicle;
[0020] a slide plate slidably attached to the base plate in a direction of movement of the striker;
[0021] a latch rotatably mounted on the slide plate that engages the striker with a rotation of the latch;
[0022] a cam rotatably mounted on the base plate; and
[0023] a motor that rotates the cam,
[0024] wherein the motor operates when the striker engages the latch to rotate the cam so as to slide the slide plate away from the roof.
[0025] According to the invention described above, when fixing the roof, a striker mounted on the roof strikes a latch, the impact of which causes the: latch to rotate and engage the striker. When the striker and latch are engaged, the motor rotates the cam, sliding a slide plate and the latch mounted thereon away from the roof, thus drawing the latch-engaged striker, together with the roof, toward the body of the vehicle.
[0026] Preferably, the base plate is provided with a guide slot in the direction of movement of the striker, the slide plate has a slide projection that engages the guide slot, and the cam has a cam slot that engages the slide projection to slide the slide projection along the guide slot as the cam rotates.
[0027] Additionally, in order to achieve the above-described objects of the present invention, according to a second aspect of the present invention there is provided the retractable roof fixing apparatus described above, wherein the slide plate has a slide projection, the cam has a cam slot that engages the cam to slide the slide projection in the direction of movement of the striker with a rotation of the cam, and the cam slot has a shape that gradually decreases retraction when the slide projection approaches a retraction limit position.
[0028] Preferably, the base plate is provided with a guide slot in the direction of movement of the striker, the slide projection engages the guide slot, and the shape of the cam slot at an engaging portion that engages when the slide projection approaches an end portion opposite the roof of the guide slot is such that an angle of intersection between the engaging portion and the guide slot gradually approaches a right angle with the rotation of the cam.
[0029] According to the invention described above, when fixing the roof, a striker mounted on the roof strikes a latch, the impact of which causes the latch to rotate and engage the striker. When the striker and latch are engaged, the motor rotates the cam, sliding a slide plate and the latch mounted thereon away from the roof, thus drawing the latch-engaged striker, together with the roof, toward the body of the vehicle.
[0030] When the striker, latch and slide plate approach the retraction limit position, the force of the roof attempting to lift the latch and slide plate upward gradually increases, but because the extent to which the slide projection is retracted gradually diminishes, the cam can be rotated with minimal force, thus offsetting an increase in the force attempting to counter-rotate the cam and making it possible to limit the load on the motor.
[0031] Additionally, in order to achieve the above-described objects, according to a third aspect of the present invention there is provided the retractable roof fixing apparatus described above, wherein the base plate has lateral slots along both lateral portions thereof, the lateral slots extending in a direction of movement of the striker, and further comprising sliders mounted at top and bottom portions along both lateral portions of the slide plate slidably engaging the lateral slots.
[0032] Preferably, the base plate is provided with a guide slot situated between and parallel to the lateral slots, a slide projection provided on an intermediate portion of the slide plate slidingly engages the guide slot, and the cam is provided with a cam slot that engages the slide projection and slides the slide projection along the guide slot as the cam rotates.
[0033] According to the invention described above, when fixing the roof, a striker mounted on the roof strikes a latch, the impact of which causes the latch to rotate and engage the striker. When the striker and latch are engaged, the motor engages and rotates the cam, sliding a slide plate and the latch mounted thereon away from the roof, thus greatly drawing the latch-engaged striker, together with the roof, toward the body of the vehicle.
[0034] Additionally, in order to achieve the above-described objects, according to a fourth aspect of the present invention there is provided the retractable roof fixing apparatus described above, further comprising: a geared cable connecting the motor and the cam; a first spring disposed between the slide plate and the base plate urging the slide plate toward the roof; and a second spring disposed between the cam and the base plate rotating the cam in a direction that draws the slide plate toward the roof.
[0035] Preferably, the first spring is disposed along each lateral surface of the slide plate and the base plate so as to urge the slide plate toward the roof.
[0036] According to the invention described above, when fixing the roof, a striker mounted on the roof strikes a latch, the impact of which causes the latch to rotate and engage the striker. When the striker and latch are engaged, the motor rotates the cam that is connected to the motor by a geared cable, sliding a slide plate and the latch mounted thereon away from the roof, thus greatly drawing the latch-engaged striker, together with the roof, toward the body of the vehicle.
[0037] When the striker is released from the latch, a tensile force exerted on the geared cable via the cam by the force of the striker lifting the latch suddenly disappears. However, the springs tensioning the slide plate and the cam apply a tensile force to the geared cable to prevent the geared cable from buckling.
[0038] Additionally, in order to achieve the above-described objects, according to a fifth aspect of the present invention there is provided the retractable roof fixing apparatus described above, wherein, the base plate is provided with a guide slot extending in a direction of movement of the striker, the slide plate has a slide projection slidingly engaging the guide slot, and the cam is provided with a pair of cam slots that engages the slide projections and slides the slide projections along the guide slots as the cam rotates, end portions of the guide slots having a straight portion disposed substantially perpendicularly to the guide slots when the slide projections reach end portions of the cam slots.
[0039] According to the invention described above, when fixing the roof, a striker mounted on the roof strikes a latch, the impact of which causes the latch to rotate and engage the striker. When the striker and latch are engaged, the motor engages and rotates the cam, sliding a slide plate and the latch mounted thereon away from the roof, thus greatly drawing the latch-engaged striker, together with the roof, toward the body of the vehicle.
[0040] When the slide projections are at end portions of the guide slots, at a top dead center position and a bottom dead center position, the edge portions of the cam slots formed as straight lines are disposed perpendicular to the guide slots, such that, even with a force exerted so as to slide the slide projections along the guide slots, such force acts at right angles to the cam slots, and therefore the cam does not rotate, and as a result, the slide plate does not slide without the motor being engaged.
[0041] Other objects, features and advantages of the present invention will be apparent from the following description when taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] [0042]FIG. 1 is a diagram showing a rear view of a retractable roof fixing apparatus according to one embodiment of the present invention, in a state in which the roof is extended;
[0043] [0043]FIG. 2 is a diagram showing a rear view of the retractable roof fixing apparatus according to one embodiment of the present invention, in a state in which a striker is retracted;
[0044] [0044]FIG. 3 is a diagram showing a front view of the retractable roof fixing apparatus according to one embodiment of the present invention, in a state in which the roof is extended;
[0045] [0045]FIG. 4 is a diagram showing a front view of the retractable roof fixing apparatus according to one embodiment of the present invention, in a state in which the striker is retracted;
[0046] [0046]FIG. 5 is a diagram showing a rear view of a motor and a cam;
[0047] [0047]FIG. 6 is a diagram showing a rear cross-sectional view of a base plate and a slide plate; and
[0048] [0048]FIGS. 7A, 7B, 7 C and 7 D are diagrams showing steps in a process of retracting and storing the roof.
DETAILED DESCRIPTION
[0049] Preferred embodiments of the present invention are now described in detail, with reference to the accompanying drawings.
[0050] [0050]FIGS. 7A, 7B, 7 C and 7 D are diagrams showing steps in a process of retracting and storing the roof.
[0051] As shown in FIG. 7A, the retractable roof fixing apparatus of the present invention fixedly mounts a base portion of a roof a on a cover c on a body b of a vehicle in such a way that the cover c can be opened and closed, and is comprised of a striker 1 mounted on the base of the roof a and a main unit mechanism 2 mounted on the cover c.
[0052] When the roof a is closed (that is, retracted), as shown in FIG. 7B, the retractable roof fixing apparatus A is released, the base of the roof a is released from the body b, and thereafter, as shown in FIG. 7C, the cover c is opened and the roof a is folded, and then, as shown in FIG. 7D, the folded roof a is stored in a rear part of the body b and the cover c is closed.
[0053] The striker 1 is a metal rod bent generally in the shape of a staple and mounted so that the base of the roof a projects toward the body b, as shown in FIGS. 3 and 4.
[0054] The main unit mechanism 2 , as shown in FIGS. 1, 2, 3 , 4 and 5 , is comprised of a base plate 3 mounted on the cover c, a slide plate 4 slidably mounted on the base plate 3 , a cover plate 5 mounted on the slide plate 4 , a latch 6 and a detent lever 7 rotatably mounted on the cover plate 5 , a cam 8 rotatably attached to the base plate 3 , and a motor 9 that rotates the cam 8 .
[0055] The base plate 3 is mounted on the cover c at a roof mounting location by screws. Additionally, as shown in FIGS. 1 and 2, slots 10 extending vertically (that is, in a direction of movement of the striker 1 ) are provided along both lateral end portions of the base plate 3 , and a somewhat shorter guide slot 11 is provided in between and parallel to the lateral edge slots 10 .
[0056] The slide plate 4 , as shown in FIGS. 3 and 4, is provided with flanges 12 on a front surface of the base plate 3 , with both lateral end portions bent toward the base plate 3 and extending further outward therefrom.
[0057] [0057]FIG. 6 is a diagram showing a rear cross-sectional view of a base plate and a slide plate.
[0058] As shown in FIG. 6, sliders 15 , each comprised of a shaft 13 and a head 14 , are provided at top and bottom portions of both lateral flanges 12 . A diameter of the shafts 13 is somewhat smaller than a width of the slots 10 of the base plate 3 , whereas the heads 14 have a diameter that is somewhat larger than the width of the slots 10 . Inserting the shaft 13 into the slot 10 through a washer 16 mounts the slider plate 4 on the base plate 3 so that the slider plate 4 slides along the slot 10 .
[0059] A slide projection 17 that slidingly engages the guide slot 11 of the base plate 3 is provided at a center of a rear surface of the slide plate 4 , as shown in FIGS. 1 and 2.
[0060] Additionally, a first spring 18 and a second spring 19 that urge the base plate 4 upward (that is, in a direction contacting the roof) are provided between the lateral edge slots 10 and the guide slot 11 , in an area between the base plate 3 and the slide plate 4 , as shown in FIG. 4.
[0061] As shown in FIGS. 3 and 4, the cover plate 5 is mounted on a front surface of the slide plate 4 (that is, a surface on the opposite side of the base plate 3 ), and is provided with a striker entry slot 20 formed in a central part of a top edge of the cover plate 5 .
[0062] The latch 6 is mounted on one side of the striker entry slot 20 of the cover plate 5 by a first shaft 21 , and the detent lever 7 is mounted on an opposite side thereof by a second shaft 22 so as to be adjacent to the latch 6 .
[0063] A notch 23 adapted to engage the striker 1 is formed on a periphery of the latch 6 , with one side of a tip of the notch 23 formed into a striking surface 24 .
[0064] In an open state, in which the striker 1 is not engaged, the striking surface 24 is disposed laterally across the striker entry slot 20 of the cover plate 5 , in the direction of the roof a.
[0065] When the striker 1 advances into the striker entry slot 20 and strikes the striking surface 24 , the impact of such contact causes the latch 6 to rotate to the right in the diagram, and the notch 23 enters a closed state, lying substantially perpendicularly across the striker entry slot 20 while fully enclosing the striker 1 . In such a state, the striker 1 cannot escape from the notch 23 .
[0066] Additionally, continuous with the striking surface 25 , an outer peripheral surface of the latch 6 disposed opposite the detent lever 7 is formed into the shape of an arc.
[0067] An engagement projection 25 is formed on an edge of the detent lever 7 disposed opposite the latch 6 . A third spring 26 is interposed between the latch 6 and the detent lever 7 . The engagement projection 25 of the detent lever 7 is urged toward the latch 6 (that is, rotates to the right in the diagram).
[0068] It should be noted that the latch 6 is urged in a direction of release (that is, rotates to the left in the diagram) by the third spring 26 .
[0069] When the latch 6 is in a state of release and the striking surface 24 lies across the-striker entry slot 20 , the engagement projection 25 of the detent lever 7 contacts the outer periphery of the curve of the latch 6 .
[0070] After the striker 1 strikes the striking surface 24 and begins to rotate to the right, the engagement projection 25 moves along the outer peripheral surface of the latch 6 until the latch 6 enters a closed state, at which time the engagement projection 25 engages the striking surface 24 , thereby restricting a leftward rotation (that is, rotation in the direction of release) of the latch 6 .
[0071] When the detent lever 7 , which is in a rotation restriction position that restricts rotation of the latch 6 is itself rotated, that is, rotated leftward against the force of the third spring 26 , the engagement between the striking surface 24 and the engagement projection 25 is released and the latch 6 is pulled by the third spring 26 and rotated in one motion to a release position.
[0072] An engagement-release mechanism involving the striker 1 , latch 6 and detent lever 7 like that described above is conventionally well known, and therefore a description using diagrams is omitted.
[0073] It should be noted that, a first switch 27 is provided at a position at which the cover plate 5 is disposed opposite the detent lever 7 . The first switch 7 detects when the latch 6 has moved to a locked position and the detent lever 7 has rotated to a rotation restriction position, and starts the motor 9 , and also detects when the detent lever 7 has returned to its original position from the rotation restriction position and the latch 6 has moved to the release position, and reverses the motor 9 .
[0074] The cam 8 , as shown in FIGS. 1 and 2, is mounted on a rear surface of the base plate 3 so as to rotate about a third shaft 28 provided below the guide slot 11 .
[0075] The cam 8 is further provided with a cam slot 29 that is curved so that a distance from the third shaft 28 gradually increases from one end to the other, with the slide projection 17 of the slide plate 4 slidingly engaged by the cam slot 29 .
[0076] Additionally, as shown in FIG. 5, when the cam 8 is connected to the motor 9 by a geared cable 30 , such as disclosed in JP 6-294455A, and the motor 9 is run in either forward or reverse, the cam 8 rotates either clockwise or counter-clockwise.
[0077] When the motor 9 is engaged and the cam 8 rotates, the slide projection 17 engaging the cam slot 29 separates from the third shaft 28 and slides between a top end and a bottom end of the guide slot 11 . As a result, the slide plate 4 , as well as the latch 6 and detent lever 7 mounted on the slide plate 4 by the cover plate 5 , move vertically with respect to the base plate 3 . At this time, the sliders 15 provided at the top-and bottom of both sides of the slide plate 4 engage the slots 10 and the slide plate 4 is supported at four points by the base plate 3 so as to slide smoothly and without rattling along a stable track.
[0078] It should be noted that the length of the guide slot 11 , that is, a distance through which the slide plate 4 ascends and descends, is approximately 40 mm.
[0079] Additionally, the cam 8 , as shown in FIGS. 1 and 2, is urged by a fourth spring 31 so that the slide projection 17 ascends (that is, the cam 8 moves toward the right in the diagrams).
[0080] Both end portions of the cam slot 29 are substantially straight lines while an intermediate portion of the cam slot 29 curved in approximately an arc, and when the slide projection 17 engages either end of the cam slot 29 , the cam slot 29 intersects the guide slot 11 at substantially a right angle.
[0081] Therefore, when the slide projection 17 engages the ends of the cam slot 29 , in other words, when the slide plate 4 is positioned at either a top dead center position or a bottom dead center position, so long as the motor is not engaged, the cam 8 does not rotate and move the slide plate 4 up or down.
[0082] Additionally, because the ends of the cam slot 29 are substantially straight lines, the slide plate 4 , in the vicinity of the top dead center position (that is, a position at which the striker 1 strikes the latch 6 ) or the bottom dead center position (that is, the retraction limit position) thereof, does not move greatly either up or down even if the cam 8 rotates, and thus the load on the motor 9 is small.
[0083] At the same time, when the slide projection 17 engages an intermediate portion of the cam slot 29 , and the slide plate 4 is in the process of moving up or down, the load on the motor 9 is large and the extent of the movement of the slide plate 4 with respect to the extent of rotation of the cam 8 increases.
[0084] Further, as shown in FIG. 2, a second switch 32 is provided on the rear surface of the base plate 3 that detects the position of the cam 8 and stops the motor 9 when the cam 8 is fully rotated leftward (hereinafter “bottom dead center”) and the slide projection 17 is positioned at one end of the cam slot 29 (that is, the end near the third shaft 28 ) so as to engage the bottom end of guide slot 11 , together with a third switch 33 as shown in FIG. 1 that detects the position of the cam 8 and stops the motor 9 when the cam 8 is fully rotated rightward (hereinafter “top dead center”) and the slide projection 17 is positioned at the other, distal end of the cam slot 29 (that is, the end far from the third shaft 28 ) so as to engage the top end of the guide slot 11 .
[0085] Next, a description is given of steps in the operation of the retractable roof fixing apparatus A.
[0086] In a state in which the roof a is not mounted on the vehicle body b, as shown in FIG. 1 the cam 8 is at a top dead center, the slide projection 17 engages the distal end of the cam slot 29 and the slide plate 4 is at a top dead center position.
[0087] At this time, the latch 6 and the detent lever 7 provided on the slide plate 4 also ascend, and although not shown, the latch 6 is in a released state and the engagement projection 25 of the detent lever 7 contacts the peripheral surface of the curve of the latch 6 .
[0088] When the roof a is closed (that is, retracted) the striker 1 enters the striker entry slot 20 of the cover plate 5 and strikes the striking surface 24 of the latch 6 , whereupon the impact of such contact rotates the latch 6 and, as shown in FIG. 3, the striker 1 , which has engaged the notch 23 of the latch 6 , is retracted approximately 5-7 mm.
[0089] Additionally, with the rotation of the latch 6 , the engagement projection 25 of the detent lever 7 moves along the outer periphery of the latch 6 , and when the latch 6 reaches the closed position, the engagement projection 25 engages the striking surface 24 so as to restrict reverse rotation of the latch 6 . The first switch 27 then detects that the detent lever 7 has reached the rotation restriction position and starts the motor 9 , and the cam 9 begins to rotate to the left.
[0090] When the cam rotates to the left, the slide projection 17 engaging the cam slot 29 gradually approaches the third shaft 28 and descends along the guide slot 11 . As a result, the slide plate 4 and the latch 6 and detent lever 7 that move with the slide plate 4 descend, and the striker, which has engaged the latch 6 , is pulled toward the body b.
[0091] It should be noted that, when the slide plate 4 and the slide projection 17 approach the top dead center position, the force with which the roof a attempts to lift the latch 6 is small, and the extent of retraction of the slide projection 17 with respect to the extent of rotation of the cam 8 is small, and therefore the load on the motor can remain small.
[0092] When the slide plate 4 and the slide projection 17 approach the bottom dead center position (the retraction limit position), the lifting force of the roof a gradually increases and the force attempting to rotate the cam in reverse also increases.
[0093] By contrast, when the slide projection 17 approaches the bottom dead center position, the angle of intersection of the cam slot 29 of the cam rotating so as to approach bottom dead center and the guide slot 11 gradually approaches a right angle, and therefore the extent of the retraction of the slide projection 17 with respect to the extent of rotation of the cam 8 gradually diminishes, so the cam 8 can be rotated with only a small amount of force.
[0094] Therefore, the load on the motor 9 , which increases due to the force attempting to rotate the cam 8 in reverse, is offset, and the cam 8 can be rotated efficiently.
[0095] As shown in FIG. 2, when the cam reaches bottom dead center, the second switch 32 detects it and stops the motor 9 , thus stopping the slide plate 4 and latch 6 at the bottom dead center position as shown in FIG. 4. At this time, the striker 1 , which has engaged the latch 6 , is further retracted approximately another 40 mm beyond that retraction when the latch 6 is at the top dead center position.
[0096] Additionally, in the state described above, the slide projection 17 engages the straight part of the cam slot 29 intersecting the guide slot 11 at a right angle, and therefore the slide plate 4 does not ascend even if a force that attempts to lift up the latch 6 is exerted through the striker 1 .
[0097] When the detent lever 7 is rotated and the engagement between the engagement projection 25 and the striking surface 24 is released, the latch 6 , which is urged by the first spring 18 , returns to the release position, the striker 1 escapes from the notch 23 and the base of the roof a separates from the cover c.
[0098] Simultaneously, the first switch 27 is activated, the motor 9 rotates in reverse and the cam 8 rotates to the right. As a result, slide projection 17 , which engages the cam slot 29 , gradually withdraws from the third shaft 28 , ascending along the guide slot 11 .
[0099] With the ascent of the slide projection 17 , the slide plate 4 , the latch 6 and the detent lever 7 also rise.
[0100] When the cam 8 reaches top dead center, the third switch 33 detects it and stops the motor. At this time, the slide plate 4 returns to the top dead center position and the latch 6 , rotated to the release position, returns to a position to receive the above-described striker 1 .
[0101] According to the present embodiment, when the striker engages the latch, the latch not only rotates and retracts the striker but also the latch itself slides away from the roof and further greatly retracts the striker, thus enabling the roof to be securely fixed to the body.
[0102] A description is now given of a second embodiment of the present invention.
[0103] It should be noted that the basic structure and function of the second embodiment are identical to those of the first embodiment described above, and therefore a description thereof is omitted here.
[0104] According to the second embodiment of the present invention, a slide projection is provided on the slide plate, the slide projection engages the cam, the cam has a cam slot that slides the slide projection in the direction of movement of the striker with a rotation of the cam, and the cam slot has a shape that gradually decreases retraction when the slide projection approaches a retraction limit position.
[0105] One end of the cam slot 29 (that is, the end near the third shaft 28 ) is substantially straight over a comparatively long distance, with the other end formed straight over a shorter distance and an intermediate portion curved in approximately an arc. When the slide projection 17 engages either end of the cam slot 29 and either end of the guide slot 11 at the same time, the cam slot 29 intersects the guide slot 11 at substantially a right angle.
[0106] Therefore, when the slide projection 17 engages the ends of the cam slot 29 , in other words, when the slide plate 4 is positioned at either a top dead center position or a bottom dead center position, the force that attempts to slide the slide projection 17 along the guide slot 11 works at a right angle to the cam slot 29 , and therefore, so long as the motor is not started, the cam 8 does not rotate and move the slide plate 4 up or down even as the striker 1 attempts to push the latch 6 down or pull the latch 6 up.
[0107] Additionally, because the ends of the cam slot 29 intersect the guide slot 11 at approximately right angles as described above, the slide projection 17 , in the vicinity of the top dead center position (that is, a position at which the striker 1 strikes the latch 6 ) or the bottom dead center position (that is, the retraction limit position) thereof, does not move greatly either up or down even if the cam 8 rotates, and thus the load on the motor 9 is small.
[0108] It should be noted that, when the slide plate 4 and the slide projection 17 approach the top position, the force with which the roof a attempts to lift the latch 6 is small, and the extent of retraction of the slide projection 17 with respect to the extent of rotation of the cam 8 is small, and therefore the load on the motor can remain small.
[0109] When the slide plate 4 and the slide projection 17 approach the bottom position (the retraction limit position), the lifting force of the roof a gradually increases and the force attempting to rotate the cam in reverse also increases.
[0110] By contrast, when the slide projection 17 approaches the bottom position, the angle of intersection of the cam slot 29 of the cam rotating so as to approach bottom dead center and the guide slot 11 gradually approaches a right angle, and therefore the extent of the retraction of the slide projection 17 with respect to the extent of rotation of the cam 8 gradually diminishes, so the cam 8 can be rotated with only a small amount of force.
[0111] Therefore, the load on the motor 9 , which increases due to the force attempting to rotate the cam 8 in reverse, is offset, and the cam 8 can be rotated efficiently.
[0112] According to the second embodiment of the present invention as described above, when the striker engages the latch, the latch not only rotates and retracts the striker but also the latch itself slides away from the roof and further greatly retracts the striker, thus enabling the roof to be securely fixed to the body.
[0113] Additionally, although the load on the motor increases due to the force with which the roof attempts to lift the latch as the slide projection approaches the retraction limit position, the extent of the retraction of the slide projection gradually diminishes and the rotation of the cam can be accomplished with only a small amount of force. As a result, any increase in the load on the motor can be limited.
[0114] A description is now given of a third embodiment of the present invention. It should be noted that the basic structure and function of the third embodiment are identical to those of the first embodiment described above, and therefore a description thereof is omitted here.
[0115] According to the third embodiment of the present invention, the base plate has lateral slots along both lateral portions thereof, with the lateral slots extending in a direction of movement of the striker, and further has sliders mounted at top and bottom portions along both lateral portions of the slide plate slidably engage the lateral slots, with the base plate provided with a guide slot situated between and parallel to the lateral slots, a slide projection provided on an intermediate portion of the slide plate slidingly engages the guide slot, and the cam is provided with a cam slot that engages the slide projection and slides the slide projection along the guide slot as the cam rotates.
[0116] Both end portions of the cam slot 29 are substantially straight lines while an intermediate portion of the cam slot 29 curved in approximately an arc, and when the slide projection 17 engages either end of the cam slot 29 , the cam slot 29 intersects the guide slot 11 at substantially a right angle.
[0117] Therefore, when the slide projection 17 engages the ends of the cam slot 29 , in other words, when the slide plate 4 is positioned at either a top dead center position or a bottom dead center position, so long as the motor is not engaged, the cam 8 does not rotate and move the slide plate 4 up or down.
[0118] Additionally, because the ends of the cam slot 29 are substantially straight lines, the slide plate 4 , in the vicinity of the top dead center position (that is, a position at which the striker 1 strikes the latch 6 ) or the bottom dead center position (that is, the retraction limit position) thereof, does not move greatly either up or down even if the cam 8 rotates, and thus the load on the motor 9 is small.
[0119] According to the third embodiment as described above, when the striker engages the latch, the latch not only rotates and retracts the striker but also the latch itself slides away from the roof and further greatly retracts the striker, thus enabling the roof to be tightly fixed to the body.
[0120] Additionally, the slide plate that supports the latch is itself supported at four points by the base plate, and therefore moves smoothly along a stable track. As a result, the latch that retracts the striker also moves smoothly and without rattling.
[0121] A description is now given of a fourth embodiment of the present invention. It should be noted that the basic structure and function of the fourth embodiment are identical to those of the first embodiment described above.
[0122] According to a fourth embodiment of the present invention, a geared cable connects the motor and the cam, a first spring is disposed between the slide plate and the base plate so as to urge the slide plate toward the roof, and a second spring is disposed between the cam and the base plate so as to rotate the cam in a direction that draws the slide plate toward the roof.
[0123] One end of the cam slot 29 (that is, the end near the third shaft 28 ) is substantially straight over a comparatively long distance, with the other end formed straight over a shorter distance and an intermediate portion curved in approximately an arc. When the slide projection 17 engages either end of the cam slot 29 and either end of the guide slot 11 at the same time, the cam slot 29 intersects the guide slot 11 at substantially a right angle.
[0124] Therefore, when the slide projection 17 engages the ends of the cam slot 29 , in other words, when the slide plate 4 is positioned at either a top position or a bottom position, so long as the motor is not started, the cam 8 does not rotate and move the slide plate 4 up or down.
[0125] Additionally, because the ends of the cam slot 29 are substantially straight lines, the slide plate 4 , in the vicinity of the top position (that is, a position at which the striker 1 strikes the latch 6 ) or the bottom position (that is, the retraction limit position) thereof, does not move greatly either up or down even if the cam 8 rotates, and thus the load on the motor 9 is small.
[0126] According to the fourth embodiment as described above, when fixing the roof, a striker mounted on the roof strikes a latch, the impact of which causes the latch to rotate and engage the striker. When the striker and latch are engaged, the motor rotates the cam that is connected to the motor by the geared cable, sliding a slide plate and the latch mounted thereon away from the roof, thus greatly drawing the latch-engaged striker, together with the roof, toward the body of the vehicle.
[0127] When the striker is released from the latch, a tensile force exerted on the geared cable via the cam by the force of the striker lifting the latch suddenly disappears. However, the springs tensioning the slide plate and the cam apply a tensile force to the geared cable to prevent the geared cable from buckling.
[0128] A description is now given of a fifth embodiment of the present invention. It should be noted that the basic structure and function of the fifth embodiment are identical to those of the first embodiment described above, and therefore a description thereof is omitted here.
[0129] According to the fifth embodiment of the present invention, the base plate has a pair of guide slots extending in a direction of movement of the striker as well as a pair of slide projections provided on the slide plate slidingly that engage the guide slots, with the cam provided with a pair of cam slots that engage the slide projections and slide the slide projections along the guide slots as the cam rotates.
[0130] Both end portions of the cam slot 29 are substantially straight lines while an intermediate portion of the cam slot 29 curved in approximately an arc, and therefore when the slide projection 17 engages the ends of the cam slot 29 and the ends of the guide slots 11 , the cam slots 29 intersect the guide slots 11 at substantially a right angle.
[0131] Therefore, when the slide projections 17 engage the ends of the cam slots 29 , in other words, when the slide plate 4 is positioned at either a top dead center position or a bottom dead center position, so long as the motor is not engaged, the cam 8 does not rotate and move the slide plate 4 up or down.
[0132] Additionally, because the ends of the cam slot 29 are substantially straight lines, the slide plate 4 , in the vicinity of the top dead center position (that is, a position at which the striker 1 strikes the latch 6 ) or the bottom dead center position (that is, the retraction limit position) thereof, does not move greatly either up or down even if the cam 8 rotates, and thus the load on the motor 9 is small.
[0133] According to the fifth embodiment of the present invention as described above, when the slide projections are at end portions of the guide slots, that is, at a top dead center position and a bottom dead center position, the edge portions of the cam slots formed as straight lines are disposed perpendicular to the guide slots, such that, even with a force exerted so as to slide the slide projections along the guide slots, such force acts at right angles to the cam slots, and therefore the cam does not rotate, and as a result, the slide plate does not slide without the motor being engaged.
[0134] It should be noted that the shape of the latch and the detent lever, and the construction and mounting positions of the springs, are not limited to that shown in the diagrams.
[0135] The present invention is not limited to the above-described embodiments, and various modifications may be made thereto within the spirit and scope of the present invention. Therefore, in order to apprise the public of the scope of the present invention, the following claims are made. | A retractable roof fixing apparatus capable of drawing the roof to a vehicle body to be snugly fixed thereto by automatically retracting a striker engaged with a latch by a sufficient distance. The retractable roof fixing apparatus comprises: a striker fixed on a roof; a base plate fixed on a body of a vehicle; a slide plate slidably attached to the base plate in a direction of movement of the striker; a latch rotatably mounted on the slide plate that engages the striker with a rotation of the latch; a cam rotatably mounted on the base plate; and a motor that rotates the cam, wherein the motor operates when the striker engages the latch to rotate the cam so as to slide the slide plate away from the roof. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation of Application PCT/JP2007/055197, filed on Mar. 15, 2007, now pending, the contents of which are herein wholly incorporated by reference.
FIELD
The present invention relates to a technology of acquiring route trace information in a GMPLS (Generalized Multi-Protocol Label Switching)/MPLS (Multi-Protocol Label Switching) network.
BACKGROUND
At first, the GMPLS/MPLS network and a path establishing signaling protocol used in the GMPLS/MPLS will briefly be explained. Then, thereafter, a conventional route tracing method will be described.
(GMPLS/MPLS)
The GMPLS/MPLS is a technology of forwarding data according to label information. The label information is defined such as a fixed length label attached to the head of a packet, a timeslot of time division transmission and a light wavelength in optical multiplexing transmission. Particularly, a network for forwarding the packet by use of the fixed length label attached to the head of the packet is called an MPLS network. Note that the GMPLS network involves using any one piece or some pieces of label information including the fixed length label employed in the MPLS network.
For example, in the packet transfer using the fixed length label, a relay node (LSR: Label Switched Router) retains a label table having a relationship between a tuple of input label/input IF (Interface) and a tuple of output label/output IF (Interface). Then, when relaying the packet, the output IF is determined based not on an address but on the label attached to the received packet, the label attached to the packet is rewritten into the output label, and the packet is thus relayed. This process being repeated, the packet is transmitted to the destination. Note that a relay node at an ingress (ingress node) of the GMPLS/MPLS network attaches the label for the first time. This is the fast packet relay technology.
FIG. 21 is an explanatory diagram of a packet relay method. Herein, the packet is forwarded to an LSR 4 from an LSR 1 . To begin with, the LSR 1 attaches a label a to the packet to be forwarded. Then, the LSR 2 , when receiving the packet attached with the label a via an interface IF# 1 , acquires the output IF and the output label by searching the label table. Subsequently, after rewriting the label of the packet into the output label, the packet is output to the output IF. This process being repeated, the packet is forwarded to an egress LSR 4 (egress node). Thus, the packet is forwarded according to the fixed length label, thereby enabling the packet relay to be speeded up.
Moreover, in the relay node, bandwidth guarantee for each packet flow can be implemented by associating each label with bandwidth control in the relay node.
In the time division transmission, each node retains a label table having a relationship between a tuple of input timeslot/input IF (Interface) and a tuple of output timeslot/output IF. Then, each node determines, based on a reception IF and a reception timeslot, the output IF and the output timeslot, and outputs the data to the output timeslot of the output IF. This process being repeated, the data is transmitted to the destination.
In the optical multiplexing transmission, each node retains a label table having a relationship between a tuple of input light wavelength/input IF (Interface) and a tuple of output light wavelength/output IF. Then, each node determines, based on the reception IF and the reception light wavelength, the output IF and the output light wavelength, then converts the reception light wavelength into the output light wavelength, and outputs the data to the output IF. This process being repeated, the data is transmitted to the destination.
The GMPLS is a technology of performing the transfer with the same mechanism in a way that deals with each of the fixed length label, the timeslot and the light wavelength as the label.
(Path Establishing Signaling Protocol (RSVP-TE: Resource reSerVation Protocol-Traffic Extension))
FIG. 22 is a diagram illustrating an operation of the path establishing signaling protocol.
In the GMPLS/MPLS, each node is required to organize the label table. Therefore, the path establishing signaling protocol (CR-LDP (Constraint-based Routing Label Distribution Protocol)/RSVP-TE) as in FIG. 22 is employed.
Hereinafter, the path establishing operation with the aid of organizing the label table will be described by exemplifying the RSVP-TE. The ingress node making the path establishing request transmits a path establishing request message (Path message) to the egress node of the path in a hop-by-hop (node-to-node) mode. In the example of FIG. 22 , the information about the relay hop-to-hop nodes is inserted into the Path message in order to explicitly designate a route. The egress node receiving the Path message sends a path establishing response message (Resv message) for allocating the label back to the ingress node along the route on which the Path message has been transmitted. At this time, the label stored in the Resv message is registered in the label table, thereby organizing the label table for forwarding the data. A path ID is stored in both of the Path message and the Resv message and is registered together in the label table.
(Conventional Route Trace Information Acquiring Method RRO)
FIG. 23 I a diagram illustrating an operation of a route tracing function which uses RRO (Record Route Object).
The following discussion will deal with a conventional technique for actualizing the route tracing function by exemplifying the RSVP-TE. The IETF Standards (Non-Patent document 1, Non-Patent document 4) define a technique using the RRO as a technique of actualizing the route trace in the RSVP.
The operation thereof will hereinafter be described ( FIG. 23 ). The ingress node making the route trace request inserts an object RRO for making the route trace request into the path establishing request (Path)/response (Resv) message, and, after adding a self-node identifier as a RRO sub-object, transmits the path establishing message (Path message) in the hop-by-hop mode. An intermediate node receiving the Path message determines, the RRO sub-object being inserted therein, that the route tracing function is set effective, and, after adding the self-node identifier as the RRO sub-object to the list, forwards the Path message to a next hop (next node). The respective intermediate nodes execute regular procedures, whereby the RRO containing the list of the nodes via which the Path message is sent is carried through the Path message down to the egress node eventually. The egress node receiving the Path message inserts the RRO object and the sub-object containing the self-node identifier into the response (Resv) message, and sends this message back to the ingress node along the route on which the Path message has been sent. The intermediate node receiving the Resv message containing the RRO sub-object, after adding the self-node identifier as the RRO sub-object to the list, forwards the Resv message to the next hop (next node). The RRO containing the list of the nodes via which the Resv message has been sent is carried up to the ingress node through the Resv message. Each node can acquire the list of the node group located on an uplink of the self-node from the Path message and the list of the node group locates on a downlink of the self-node from the Resv message and can acquire the information about the nodes via which the established path extends from these two items of information by performing the procedures described above.
FIG. 24 is a flowchart illustrating the standard specification processing flow described above. Each relay node, upon receiving the path establishing request (or the response), checks whether this message contains the route record request (RRO) or not. The relay node, if the route record request is contained, adds the self-node identifier to the route information list and transmits the path establishing request (or the response) to the next node. If the route record request is not contained, the relay node transmits the path establishing request (or the response) as it is to the next node.
[Patent document 1] Japanese Patent Laid-Open Publication No. 2000-244563. [Non-Patent document 1] D. Awduche, L. Berger, D. Gan, T. Li, V. Srinivasan, G. Swallow, “RSVP-TE: Extensions to RSVP for LSP Tunnels.” Network Working Group Request for Comments (RFC) 3209, December 2001. [Non-Patent document 2] L. Berger, Ed., “Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description.” Network Working Group Request for Comments (RFC) 3471, January 2003. [Non-Patent document 3] L. Berger, Ed., “Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions.” Network Working Group Request for Comments (RFC) 3473, January 2003. [Non-Patent document 4] K. Kompella, Y. Rekhter, “Signaling Unnumbered Links in Resource ReSerVation Protocol-Traffic Engineering (RSVP-TE).” Network Working Group Request for Comments (RFC) 3477, January 2003. [Non-Patent document 5] J. Moy, “OSPF Version 2.” Network Working Group Request for Comments (RFC) 2328, April 1998. [Non-Patent document 6] D. Katz, K. Kompella, D. Yeung, “Traffic Engineering (TE) Extensions to OSPF Version 2.” Network Working Group Request for Comments (RFC) 3630, September 2003. [Non-Patent document 7] K. Kompella, Ed., Y. Rekhter, Ed., “Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS).” Network Working Group Request for Comments (RFC) 4202, October 2005. [Non-Patent document 8] K. Kompella, Ed., Y. Rekhter, Ed., “OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS).” Network Working Group Request for Comments (RFC) 4203, October 2005.
SUMMARY
FIG. 25 is a diagram illustrating a problem of the existing route trace.
In the network where a plurality of network domains is connected, if each domain is provided on a per-carrier basis, it is required that intra-domain information be concealed, and such a mechanism is adopted as not to disclose the information within the carrier network to the greatest possible degree in order to avoid DOS (Denial of Service) attack also in the Internet.
On the other hand, in the GMPLS/MPLS network, in the case of the RRO for acquiring the route trace information, it is specified as a rule that each node forwards the data to a neighboring node in a way that registers the self-node ID in the RRO sub-object. This mechanism has the following problems if it is not desired that the information within a certain network range (domain) is disclosed to the outside, and as a result it follows that the intra-domain information can be easily extracted from an external domain ( FIG. 25 ).
(1) A border with a network to which the information must not be disclosed can not be known.
(2) Concealing target information can not be specified from within the route information described in the route trace information.
(3) The route information described in the route trace information can not be deleted.
FIG. 26 is a diagram illustrating an operation when the RRO function is ineffective. When a node A transmits the Path message containing the RRO, a node D defined as an RRO non-implemented node sends an error purporting that the node D does not support the RRO back to the node A. The node A transmits a Path message containing none of the RRO and establishes the path.
Thus, if it is not desired to disclose the information, the information can be prevented from being leaked outside the domain if the intra-domain node is configured so as not to support the RRO ( FIG. 26 ). The route trace information acquiring function itself becomes ineffective, and hence, in the case of desiring to acquire the intra-domain route trace information, it is required that a technique different from the existing mechanism be taken.
According to an aspect of the embodiment, a relay node includes:
a receiving unit receiving a control message for a route trace, which contains route information about a path extending from an ingress node to an egress node and used for forwarding data, from an anterior node on the path;
an editing unit, if a self-node is a border node located at a border of a route information shielding zone on the path, editing, in an undistinguishable status, information about the route information shielding zone of route information contained in the route trace control message received by the receiving unit; and
a transmitting unit transmitting the route trace control message after being edited to a posterior node on the path.
Preferably, in the relay node, the editing unit adds, to the route information, pseudo information about the route information shielding zone as a substitute for the deleted information about the route information shielding zone.
Preferably, in the relay node, the route information includes a list containing an identifier of a node through which the path extends and a flag indicating whether the node belongs to the route information shielding zone or not, and
the editing unit specifies, based on the flag, the node belonging to the route information shielding zone in the list, and deletes the identifier of the specified node from the list.
Preferably, the relay node further includes a link management information database stored with a domain to which the self-node belongs and a domain to which another relay node connecting with a self-device belongs,
wherein the editing unit refers to the link management information database and thus determines whether or not the domain to which the self-device belongs is coincident with the domain to which a second relay node defined as a transmitting destination of the control message belongs, and determines that the self-node is the border node if the domain to which the self-device belongs is not coincident with the domain to which the posterior relay node device defined as the transmitting destination of the control message belongs.
Preferably, in the relay node, the editing unit, if the self-node is not the border node but belongs to the route information shielding zone, attaches the identifier of the self-node and a flag indicating that the self-node belongs to the route information shielding zone to the route trace control message received by the receiving unit.
Herein, the editing unit includes a RRO processing unit. Further, the storage unit includes a shielding target node database.
The object and advantages of the embodiment will be realized and attained by means of the elements and combinations particularly pointed out in the claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the embodiment, as claimed.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a diagram illustrating how a shielding area based on a domain is designated in a first embodiment.
FIG. 2 is a diagram illustrating a configuration of a node in the first embodiment.
FIG. 3 is a diagram illustrating a link management information database of a node 10 F (domain 2 , within a shielding area).
FIG. 4 is a flowchart illustrating a processing flow in the first embodiment.
FIG. 5 is a diagram illustrating how a shielding target flag is attached.
FIG. 6 is a diagram illustrating a sub-object deleting process by a border node.
FIG. 7 is a diagram illustrating RRO IPv4 address sub-object (Type 0x01).
FIG. 8 is a diagram illustrating RRO Unnumbered Interface ID sub-object (Type 0x04).
FIG. 9 is a diagram illustrating a process through a Resv message.
FIG. 10 is a diagram illustrating how an arbitrary shielding range is designated.
FIG. 11 is a diagram illustrating the link management information database of anode 20 C (domain 1 , within the shielding area).
FIG. 12 is a diagram illustrating how the route information is partially shielded.
FIG. 13 is a diagram illustrating an example of a network architecture in a third embodiment.
FIG. 14 is a flowchart illustrating a processing flow in the third embodiment.
FIG. 15 is a diagram illustrating a pseudo node adding process.
FIG. 16 is a diagram illustrating an example of a configuration of the node in a fourth embodiment.
FIG. 17 is a flowchart illustrating a processing flow in the fourth embodiment.
FIG. 18 is a diagram illustrating an example of specifying the shielding target node based on data matching.
FIG. 19 is a flowchart illustrating a processing flow in a fifth embodiment.
FIG. 20 is a diagram illustrating an example of specifying the shielding target node based on the data matching.
FIG. 21 is a diagram illustrating how a packet is forwarded in a way that uses a fixed length label.
FIG. 22 is a diagram illustrating an operation of a path establishing signaling protocol (RSVP-TE).
FIG. 23 is a diagram illustrating an operation of a route tracing function using RRO.
FIG. 24 is a flowchart illustrating a standard specification processing flow.
FIG. 25 is a diagram illustrating a problem of an existing route trace.
FIG. 26 is a diagram illustrating an operation when a RRO function is ineffective.
DESCRIPTION OF EMBODIMENTS
Embodiments will hereinafter be described with reference to the drawings. Configurations in the embodiments are exemplifications, and the present invention is not limited to the configurations in the embodiments. Further, the embodiments can be configured in proper combinations.
First Embodiment
Architecture
FIG. 1 is a diagram illustrating an example of a network architecture in the first embodiment. FIG. 1 illustrates an example in the case of setting a shielding target area of route information on a domain basis.
A domain can be also re-segmented corresponding to a shielding target area, in which an arbitrary range is set as the shielding target area irrespective of the domain.
Nine pieces of nodes (nodes 10 A through 10 I) exist in a network 100 in FIG. 1 . A domain 1 embraces the nodes 10 A, 10 B and 10 C, a domain 2 embraces the nodes 10 D, 10 E and 10 G, and a domain 3 embraces the nodes 10 G, 10 H and 10 I. Herein, the domain 2 is set as the shielding target area of the route information. In this case, the node located at a border of the shielding target area recognizes that a self-node is a shielding border node by use of domain attribute information (a link management information database) of the link. Herein, a link within the domain is defined as an intra-domain link, and a link establishing a connection between the domains is defined an inter-domain link. Each node manages the link (link attribute) connecting directly with the self-node.
FIG. 2 is a diagram illustrating a configuration of the node in the shielding target area of the route information in the first embodiment. The node in the shielding target area of the route information in the first embodiment includes a data receiving unit 1012 , a data relay unit 1014 , a data transmitting unit 1016 , a control packet receiving unit 1022 , a path control unit 1024 , a control packet transmitting unit 1026 , a RRO processing unit 1030 , a link management information database 1052 , and a label table 1056 .
The data receiving unit 1012 receives the data from a neighboring node and transmits the data to the data relay unit 1014 in order to determine a destination thereof.
The data relay unit 1014 receives the data from the data receiving unit 1012 . The data relay unit 1014 refers to the label table 1056 and thus determines the destination of the data received from the data receiving unit 1012 . The data relay unit 1014 attaches a label described in the label table 1056 (to the data) and transmits the data (attached with the label) to the data transmitting unit 1016 .
The data transmitting unit 1016 receives the data from the data relay unit 1014 . The data transmitting unit 1016 transmits the data attached with the label to the neighboring node.
The control packet receiving unit 1022 receives, from the neighboring node, a control packet for establishing and canceling a path. The control packet receiving unit 1022 transmits the control packet to the path control unit 1024 .
The path control unit 1024 receives the control packet from the control packet receiving unit 1022 . The path control unit 1024 implements label allocation for establishing the path in response to a request of the control packet. The path control unit 1024 registers the allocated-label information in the label table 1056 . The path control unit 1024 rewrites contents (items of data) of the control packet into those for transmission to a next neighboring node as the necessity may arise. The path control unit 1024 transmits the control packet to the control packet transmitting unit 1026 . Further, the path control unit 1024 , if the control packet contains a RRO request, transmits the control packet to the RRO processing unit 1030 . This is because the RRO processing unit 1030 executes a control packet process.
The RRO processing unit 1030 receives the control packet containing the RRO request from the path control unit 1024 . The RRO processing unit 1030 executes a Record Route Object (RRO) entry adding process. To be specific, the RRO processing unit 1030 adds RRO sub-object containing an identifier of the self-node to the RRO. Moreover, the RRO processing unit 1030 adds, to the RRO, a shielding target flag representing that the RRO sub-object is the shielding target node. Further, the RRO processing unit 1030 executes processes such as a shielding border node determining process, a shielding target route information specifying process and a shielding target route information deleting process. The RRO processing unit 1030 gets a processing result contained in the control packet and thus transmits the control packet to the control packet transmitting unit 1026 .
The control packet transmitting unit 1026 receives the control packet from the path control unit 1024 of the RRO processing unit 1030 , and transmits the control packet to the neighboring node.
The link management information database 1052 is stored with information on an associated destination domain on a per-interface basis of the self-node. Further, the link management information database 1052 is stored with information on the domain (self-domain) to which the self-node belongs. The destination domain of a specified interface is compared with the domain to which the self-node belongs, thereby making it possible to determine whether a connecting destination node of the link of the specified interface exists within the domain or outside the domain.
FIG. 3 is a diagram illustrating an example of the link management information database of the node 10 F. Each node has the link management information database 1052 . The link management information database 1052 retains the information on the domain (self-domain) to which the self-node belongs and the information about the destination domain on the per-interface basis. In the node 10 F, the node 10 F itself belongs to the domain 2 , the domain 2 is connected to an interface # 1 , and the domain 3 is connected to an interface # 2 . It is decided from this topology that the interface # 1 of the node 10 F is defined as the intra-domain link, while the interface # 2 of the node 10 F is defined as the inter-domain link.
Operational Example
FIG. 4 is a flowchart illustrating an example of a processing flow of the node within the shielding target area in the first embodiment. Herein, the discussion will be focused on an example of the node 10 F. The nodes 10 D and 10 E also execute the processes according to the same processing flow.
Herein, a path of a route extending from the node A to the node I sequentially via the node 10 B, the node 10 C, the node 10 D, the node 10 E, the node 10 F, the node 10 G and the node 10 H, is established based on a path establishing signaling protocol (RSVP-TE). The ingress node 10 A makes a route trace request by issuing a Path message containing the RRO by way of a path establishing request.
The node 10 F receives the path establishing request from the neighboring node ( FIG. 4 : S 1002 ). The node 10 F checks whether or not the path establishing request is the Path message containing the RRO (S 1004 ). If the path establishing request is the Path message which does not contain the RRO (S 1004 ; NO), after a predetermined process, this path establishing request is transmitted to the next node (S 1018 ). If the path establishing request is the Path message containing the RRO (S 1004 ; YES), a normal path establishing process is executed, and simultaneously the RRO sub-object containing the identifier of the self-node is added to the route information list (S 1006 , RRO process). The node 10 F adds a flag representing that the RRO sub-object is the shielding target (S 1008 ).
FIG. 5 is a diagram illustrating an example of how the shielding target flag is attached. In the node 10 D, the node 10 E and the node 10 F, the shielding target flag ( 1 ) representing that the RRO sub-object is the shielding target is attached together with the RRO sub-object containing the identifier (D, E, or F) of the self-node.
Next, the node 10 F specifies the interface from which the Path message should be sent. Information for specifying this interface can be acquired in such a way that the node 10 F itself implements a routing algorithm by use of information on an egress (terminal point) of the path. Moreover, if the Path message contains Explicit Route Object that designates the route, the information is acquired based on a description of the Explicit Route Object.
The node 10 F determines whether or not the self-node is located at the shielding border ( FIG. 4 : S 1010 , a shielding border node determining process). The node 10 F compares the information of the self-domain in the link management information database 1052 with the information of the destination domain of the interface from which the Path message is transmitted, thereby deciding whether the self-node is located at the shielding border or not.
Herein, in the case of the node 10 D (or the node 10 E), the information of the self-domain is coincident with the information of the destination domain ( FIG. 4 : S 1010 ; NO). At this time, the node 10 D (or the node 10 E) decides that the self-node is not located at the shielding border and, after the predetermined process, transmits the path establishing request to the next node (S 1018 ).
In the case of the node 10 F, the information of the self-domain is not coincident with the information of the destination domain ( FIG. 4 : S 1010 ; YES). At this time, the node 10 F decides that the self-node is located at the shielding border, and executes the next process. The node 10 F refers to the flag representing that the RRO sub-object is the shielding target, and thus specifies the shielding target route information (the information on the node defined as the shielding target) (S 1012 , a shielding target route information specifying process). The RRO sub-object, to which the flag representing that the RRO sub-object is the shielding target is attached, is determined to be the shielding target route information. The node 10 F deletes the RRO sub-object determined to be the shielding route information from the list (S 1014 , a shielding target route information deleting process). The node 10 transmits, after the predetermined process, the path establishing request to the next node (S 1018 ).
It is an available scheme that the node 10 F determines, before attaching the shielding target flag, whether the self-node is the shielding border node or not, and, when determining that the self-node is the shielding border node, executes neither the process of adding the RRO sub-object containing the identifier of the self-node nor the process of attaching the shielding target flag.
FIG. 6 is a diagram illustrating an example of an RRO sub-object deleting process by the border node. The node 10 F, when deciding that the self-node is the shielding border node, deletes the RRO sub-object (D, E, F) to which the flag representing that the RRO sub-object is the shielding target and this flag.
FIGS. 7 and 8 are diagrams each illustrating sub-object defined by standard. FIG. 7 depicts Type 0x01 IPv4 address sub-object, and FIG. 8 depicts Type 0x04 Unnumbered Interface ID sub-object.
In the case of using Type 0x01 IPv4 address sub-object in FIG. 7 , the node identifier is added to IPv4 address. In the case of employing Type 0x04 Unnumbered Interface ID sub-object in FIG. 8 , the node identifier is added to Router ID, and the interface number of the interface receiving the Path message containing the RRO or the interface number of the interface transmitting the Path message containing the RRO, is added to Interface ID. The shielding target flags can be realized by defining new values in Flags. The already-defined flags are given below.
0x01 Local protection available
0x02 Local protection in use
In the case of using Type 0x04 Unnumbered Interface ID sub-object in FIG. 8 , the shielding target flag may also be realized by defining a new flag in a “Reserved” field.
FIG. 9 is a diagram illustrating an example of a case of using a Resv message of a path establishing response. It is assumed that the domain 2 embracing the node 10 D, the node 10 E and the node 10 F is the shielding target area.
The node 10 F receiving the Resv message containing the RRO by way of the path establishing response from the node 10 G executes the normal path establishing process and the RRO process as well. The node 10 F adds the RRO sub-object containing the identifier of the self-node to the RRO, and attaches the shielding target flag representing that the RRO sub-object is the shielding target. Next, the node 10 F specifies the interface from which the Resv message should be sent. This information is obtained by referring to Path State generated within the node on the occasion of receiving and transmitting the Path message. After obtaining the message-should-be-sent interface (which is herein # 1 ), the node 10 F makes collation with the link attribute information (the link management information database 1052 ) managed by the self-node, and thus determines whether the interface is the intra-domain link or the inter-domain link. In the case of the node 10 F, the interface # 1 from which the Resv message should be sent next is the intra-domain link, and hence the determination is that the self-node is not the shielding border node. The node 10 F other than the shielding border node executes the process of sending the Resv message. The same process is carried out also by the node 10 E.
The node 10 D receiving the Resv message containing the RRO by way of the path establishing response from the node 10 E executes the normal path establishing process and the RRO process as well. The node 10 D adds the RRO sub-object containing the identifier of the self-node to the RRO, and attaches the shielding target flag representing that the RRO sub-object is the shielding target. The node 10 D determines whether the self-node is the shielding border node or not. The node 10 D, as the interface # 1 from which the Resv message should be sent next is the inter-domain link, determines that the self-node is the shielding border node. The node 10 D serving as the shielding border node refers to the RRO sub-object list and deletes the RRO sub-object attached with the shielding target flag from the list. Thereafter, the node 10 D registers the RRO in the Resv message and sends this message to the interface # 1 .
Operation and Effect in First Embodiment
According to the first embodiment discussed above, the normal route information can be acquired within the shielding target area without disclosing the route information of the shielding target area to the respective nodes outside the shielding target area. For example, the node 10 G outside the shielding target area acquires uplink route information {A, B, C} from the Path message and downlink route information {H, I} from the Resv message. Route information {A, B, C, G, H, I} of the path is obtained from a combination of these items of information and the information of the self-node. This is a format to conceal route information {D, E, F} within the shielding target area. On the other hand, the node 10 E within the shielding target area acquires the uplink route information {A, B, C, D} from the Path message and the downlink route information {F, G, H, I} from the Resv message. The route information {A, B, C, D, E, F, G, H, I} of the path is obtained from the combination of these items of information and the information of the self-node. This is the route information including all of the nodes on the path.
Modified Example
FIG. 10 is a diagram illustrating an example of the network architecture in a modified example of the first embodiment. FIG. 10 depicts the example in which the shielding target area of the route information is arbitrarily set irrespective of the domain.
Thirteen pieces of nodes (Nodes 20 A- 20 M) exist in a network 200 in FIG. 10 . The domain 1 embraces the nodes 20 A, 20 B, 20 C and 20 N, the domain 2 embraces the nodes 20 D, 20 e , 20 F and 20 J, the domain 3 embraces the nodes 20 G, 20 H and 20 I, and the domain 4 embraces the nodes 20 K, 20 L and 20 M.
Herein, an area circumscribed with a dotted line in FIG. 10 is defined as the shielding target area of the route information. The nodes within the shielding target area are the nodes 20 A, 20 B, 20 C, 20 D, 20 E, 20 F, 20 J, 20 K and 20 M. The shielding target area of the route information includes some proportions of the domains 1 , 4 and the whole domain 2 . Each of the nodes within the shielding target area retains the link attribute information (the link management information database) for specifying the shielding target area.
At this time, the link connecting the node 20 C and the node 20 N to each other is the intra-domain link of the domain 1 and is also the link connected to the outside of the shielding target area of the route information.
Each node in the modified example of the first embodiment has the same configuration as the configuration of the node illustrated in FIG. 2 .
FIG. 11 is a diagram illustrating an example of the link management information database retained by the node 10 C. Each node has the link management information database 1052 . The link management information database 1052 includes information on the domain (self-domain) to which the self-node belongs, information about the destination domain on the per-interface basis, and information indicating whether the destination node is within the shielding target area or outside the shielding target area. In this case, inhibition of an information disclosure to the outside of the shielding target area is set as a route information shielding policy. In the link management information database 1052 , the information on the domain (self-domain) to which the self-node belongs is not necessarily required.
Each node within the shielding target area of the route information recognizes, based on the link management information database, whether the self-node is located at the shielding border, and can execute a proper process.
Each node within the shielding target area in this modified example executes the same processes as those in the processing flow depicted in FIG. 4 . The determination about whether the self-node is located at the shielding border or not is made from knowing whether the destination node in the link management information database 1052 is within the shielding target area or outside the shielding target area. If the destination node is outside the shielding target area, it is determined that the node is located at the shielding border.
Second Embodiment
Next, a second embodiment will hereinafter be described. The second embodiment has the common points to the first embodiment. Accordingly, the discussion will be focused on different points, while the explanations of the common points are omitted.
The second embodiment will discuss a method of shielding the route information of only some of the nodes within the shielding target area of the route information.
<Configuration>
The network architecture in the second embodiment is the same as the network architecture in FIG. 1 in the first embodiment. The configuration of each node within the shielding target area of the route information in the second embodiment is the same as the configuration of the node in FIG. 2 in the first embodiment.
Further, the same network architecture as in FIG. 10 according to the modified example of the first embodiment can be taken by way of another modified example.
Operational Example
A processing flow of each node within the shielding target area of the route information is the same as the processing flow in FIG. 4 in the first embodiment. In the first embodiment, each node within the shielding target area uniformly attaches the shielding target flag representing that the RRO sub-object is the shielding target. In the second embodiment, a shielding policy can be set on a per-node basis. If a shielding non-target policy is set in a certain node, on the occasion of adding the RRO sub-object, the shielding target flag is not attached. With this scheme, as for the node in which the shielding non-target policy is set, the RRO sub-object is not deleted in the shielding border node.
FIG. 12 is a diagram illustrating an example of a RRO sub-object deleting process by the shielding border node in the second embodiment. In FIG. 12 , the domain 2 is designated as the shielding target area of the route information. Further, the node 10 D and the node 10 F are shielding non-target nodes, and the node 10 E is the shielding target node. The node 10 F, when deciding that the self-node is the shielding target node, deletes the RRO sub-object (E) attached with the flag which represents being the shielding target node and this flag as well.
Operation and Effect in Second Embodiment
According to the embodiment discussed above, within the shielding target area of the route information, each node can acquire the normal route information similarly to the case of the first embodiment. Moreover, the scheme of setting the nodes into the shielding target nodes and the shielding non-target nodes enables each node outside the shielding target area of the route information to acquire the route information for the nodes excluding the shielding target nodes within the shielding target area.
Third Embodiment
Next, a third embodiment will hereinafter be described. The third embodiment has the common points to the first embodiment. Accordingly, the discussion will be focused on different points, while the explanations of the common points are omitted.
In the first embodiment, if the node within the shielding target area of the route information becomes an ingress node, all items of route information are deleted in the shielding border node within the shielding target area, and hence it follows that the RRO containing none of the data is transmitted. It is a violation of the standard to transmit the RRO containing none of the data, which is a problem. The third embodiment solves this problem.
<Configuration>
FIG. 13 is a diagram illustrating an example of the network architecture in the third embodiment. FIG. 15 depicts an example in which the shielding target area of the route information is set on the domain basis.
Six pieces of nodes (node 30 D through 30 I) exist in a network 300 in FIG. 13 . The domain embraces the nodes 30 D, 30 E and 30 F, and the domain 3 embraces the nodes 30 G, 30 H and 30 I. The node 30 D is an ingress node. Herein, the domain 2 is set as the shielding target area of the route information. In this case, the node located at the border of the shielding target area recognizes that the self-node is the shielding border node by use of the domain attribute information (the link management information database) of the link. Herein, the link within the domain is defined as the intra-domain link, and the link establishing the connection between the domains is defined the inter-domain link. Each node manages the link (link attribute) connecting directly with the self-node.
The configuration of the shielding target node of the route information in the third embodiment is the same as the node configuration in FIG. 2 in the first embodiment.
Operational Example
FIG. 14 is a flowchart illustrating a processing flow of the node within the shielding target area in the third embodiment. Herein, the discussion will be focused on an example of the node 10 F. The processes are also executed according to the same processing flow in the nodes 10 D and the node 10 E.
In FIG. 14 , the processing flow till the shielding target route information is deleted (S 3014 ) since the path establishing request has been received (S 3002 ) is the same as the processing flow ( FIG. 4 ) in the first embodiment. If the ingress node exists within the shielding target area of the route information, however, the route information disappears when deleting the shielding target route information. Such being the case, the node 10 F defined as the shielding border node adds, as the RRO sub-object, a pseudo node (domain 2 ) acting as a representative of the shielding target domain (S 3016 ).
FIG. 15 is the diagram illustrating an example of an RRO sub-object deleting process by the border node. The node 10 F, when determining that the self-node is the shielding border node, deletes the RRO sub-object (D, E, F) attached with the flag which represents being the shielding target node and this flag as well. Moreover, the node 10 F adds, to the RRO sub-object, a pseudo node (domain 2 ) acting as the representative of the shielding target domain. This scheme makes it possible to avoid the RRO containing none of the data from being sent.
The node 10 F, after the predetermined process, transmits the path establishing request to the next node (S 3018 ).
Operation and Effect in Third Embodiment
According to the third embodiment, as depicted in FIG. 15 , if the ingress node exists within the shielding target domain and if the deleting target setting is done in all of the nodes within the domain, it follows that the RRO containing none of the data is sent unless the present function is implemented. It is the violation of the standard to send the RRO containing none of the data, however, this violation can be avoided by making use of this function.
Moreover, the scheme of adding the pseudo node in the third embodiment to the RRO sub-object can be applied to a case in which the ingress node does not exist within the shielding target area of the route information.
Fourth Embodiment
Next, a fourth embodiment will hereinafter be described. The fourth embodiment has the common points to the first embodiment. Accordingly, the discussion will be focused on different points, while the explanations of the common points are omitted.
The fourth embodiment will discusses a method of realizing the soft shielding of the route information without adding any change to the RRO sub-object.
<Configuration>
The network architecture in the fourth embodiment is the same as the example of the network architecture in FIG. 1 in the first embodiment.
Moreover, a modified example can take the same network architecture in FIG. 10 in the modified example of the first embodiment.
FIG. 16 is a diagram illustrating a configuration of the node within the shielding target area of the route information in the fourth embodiment. The node within the shielding target area of the route information in the fourth embodiment has substantially the same configuration of the node in FIG. 2 in the first embodiment. The node in the fourth embodiment further includes a shielding target node database 1054 . It is sufficient that the shielding target node database 1054 is retained by all of the nodes located leastwise at the shielding border. Namely, the nodes, which certainly do not become the shielding border nodes, may not retain the shielding target node database 1054 .
The shielding target node database 1054 is a database that describes a list of the shielding target nodes.
The RRO processing unit 1030 does not, unlike the first embodiment, attach the shielding target flag which represents being the shielding target.
Moreover, the RRO processing unit 1030 , when determining that the self-node is the shielding border node, compares the RRO sub-object list with the shielding target node database. The RRO processing unit 1030 , as a result of the comparison, deletes the node coincident with the node described in the shielding target node database from the RRO sub-object list.
Operational Example
FIG. 17 is a flowchart illustrating an example of a processing flow of the node within the shielding target area in the fourth embodiment. Herein, the discussion will be focused on an example of the node 10 F. The processes are also executed according to the same processing flow in the nodes 10 D and the node 10 E.
In FIG. 17 , the processing flow till the path establishing request is given to the next node (S 4018 ) since the path establishing request has been received (S 4002 ) is the same as the processing flow ( FIG. 4 ) in the first embodiment. The fourth embodiment does not, however, entail setting the flag which represents being the shielding target node. Further, the fourth embodiment involves using the shielding target node database 1054 in place of employing the flag which represents being the shielding target node on the occasion of specifying the shielding target route information (S 4012 ).
FIG. 18 is a diagram illustrating an example of a sub-object deleting process by the border node. The node 10 F within the shielding target area, when determining that the self-node is the shielding border node, refers to the shielding target node database 1054 and thus deletes the RRO sub-object (D, E, F).
Operation and Effect in Fourth Embodiment
According to the fourth embodiment, the shielding target node database 1054 is updated on demand without adding any change to the RRO sub-object, whereby the shielding of the route information can be realized while flexibly changing the shielding range of the route information.
Modified Example
An intra-domain topology database can be utilized in place of preparing the shielding target node database 1054 .
In the GMPLS/MPLS, a routing protocol (Non-Patent document 5, Non-Patent document 6, Non-Patent document 7, Non-Patent document 8, etc) for collecting pieces of topology information of the nodes within the network is defined as the standard. Each node can acquire the information about the nodes located within the network by use of this protocol. Information about the area can be added to the topology database, and hence, if an area value different on the per-domain basis is set, a process of setting only one domain as the shielding target can be actualized.
Fifth Embodiment
Next, a fifth embodiment will hereinafter be described. The fifth embodiment has the common points to the fourth embodiment. Accordingly, the discussion will be focused on different points, while the explanations of the common points are omitted.
The fifth embodiment will discuss a method of providing a scheme for adding the pseudo node in the third embodiment to the configuration in the fourth embodiment.
<Configuration>
The network and the respective nodes in the fifth embodiment have the same network architecture and the same node configuration as those in the fourth embodiment.
Operational Example
FIG. 19 is a flowchart illustrating an example of the processing flow of the node within the shielding target area in the fifth embodiment. Herein, the discussion will be focused on an example of the node 10 F. The processes are also executed according to the same processing flow in the nodes 10 D and the node 10 E.
In FIG. 19 , the processing flow till the shielding target route information is deleted (S 5014 ) since the path establishing request has been received (S 5002 ) is the same as the processing flow ( FIG. 17 ) in the fourth embodiment. In the fifth embodiment, after deleting the shielding target route information, similarly to the third embodiment, the pseudo node (domain 2 ) acting as the representative of the shielding target domain is added to the RRO sub-object list.
FIG. 20 is a diagram illustrating an example of the sub-object deleting process by the border node. The node 10 F within the shielding target area, when determining that the self-node is the shielding border node, refers to the shielding target node database 1054 and thus deletes the RRO sub-object (D, E, F). Further, the node 10 F adds the pseudo node (domain 2 ) to the RRO sub-object.
All example and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present inventions have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention. | A relay node comprising a reception station for receiving a route trace control message including routing information on a path used for data transfer from a starting node to a terminal node from the preceding node on the path, an editing section for, if the home node is boundary node located at the boundary of a routing information shielding section on the path, editing so that a portion on the routing information shielding section of the routing information included in the route trace control message received by the reception section cannot be identified, and a transmission section for sending out a route trace control message after the edition to the node of the subsequent stage, which is located on the path. | 7 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a tire pressure monitoring device and a method of monitoring tire pressure for a system including both a direct measurement tire pressure monitoring system and an indirect tire pressure monitoring system. The invention further relates to a computer program product for implementing the method.
[0002] It is of great significance for vehicle safety to reliably monitor the tire pressure on all wheels of a motor vehicle. There are different approaches how to realize tire pressure monitoring systems. So-called tire pressure monitoring systems with direct pressure measurement, as described in application DE 199 26 616 C2, exist which determine the respective pressure in the associated wheel by means of pressure sensors in the individual tires. Systems of this type monitor the tire pressure on all wheels independently, yet they are relatively expensive as they require additional devices, e.g. for transmitting and evaluating pressure sensor information. Further, so-called indirectly measuring tire pressure monitoring systems are known, e.g. from DE 100 58 140 A1, which can detect pressure loss based on auxiliary quantities, e.g. by comparing the rolling circumferences of the individual wheels.
[0003] These systems suffer from the disadvantage that a defective tire will only be detected at a significant pressure loss. Admittedly, systems of this type are inexpensive and reliable, yet they function only if pressure loss occurs on one wheel. If pressure loss occurs on several wheels at the same time, this condition will not be detected.
[0004] DE 100 60 392 A1 discloses a tire pressure monitoring device which comprises a combination of a tire pressure monitoring system with indirect measurement and a tire pressure monitoring system with direct measurement. The task of the tire pressure monitoring device described in this publication is to monitor inflation pressure loss on all four wheels by the combination of a tire pressure sensor and a tire pressure monitoring system with indirect measurement.
[0005] It is disadvantageous in this respect that when using only one tire pressure sensor, the wheels on which no tire pressure sensors are mounted can only be monitored with relatively high detection thresholds. The consequence is that inflation pressure loss is detected at a very late point of time only. It is achieved by the alternative use of two tire pressure sensors as mentioned in the above publication, with exactly one tire pressure sensor being arranged on each vehicle axle, that individual tire pressure nominal values can be determined for each axle. However, this provision does not lead to a considerably earlier detection of inflation pressure loss. As a tire pressure monitoring system with indirect measurement operates on the basis of rotational wheel speeds and, hence, is directly dependent on the wheel rolling circumference, pressure loss on the driven wheels can frequently be detected only very insufficiently or in rare moments of their free rolling.
[0006] When using a tire pressure sensor on only one wheel of the driven axle, it is only possible to detect very great pressure losses on the other driven wheel. Besides, there is still the problem that wheel slip on a driven wheel can be interpreted as pressure loss on this wheel by the tire pressure monitoring system with indirect measurement because the tire pressure monitoring system with indirect measurement does not identify whether the wheel speed increase is due to a defective tire or a slip situation. For reasons of rigidity, it is therefore possible in a tire pressure monitoring system of this type to use only high detection thresholds for pressure loss detection.
SUMMARY OF THE INVENTION
[0007] In view of the above, an object of the invention is to provide a tire pressure monitoring device and a method of monitoring the tire pressure for safely detecting, in a reliable and low-cost fashion, pressure loss on several or all tires of a motor vehicle at an early time, in consideration of the wheel slip and at a high rate of accuracy.
[0008] This object is achieved by a tire pressure monitoring device having a direct measurement tire pressure monitoring system and an indirect tire pressure monitoring system and a method of monitoring the tire pressure using the tire pressure monitoring device.
[0009] It is preferred that in a vehicle with several driven vehicle axles, the tire pressure monitoring system with direct measurement is arranged on the vehicle axle to which the maximum driving torque of the vehicle engine is applied. As a result, pressure loss on the driven axle is also detected when the driven wheels are exposed to driving torque or wheel slip, respectively, e.g. when the vehicle is accelerating. The non-driven wheels can be monitored safely by a tire pressure monitoring system with indirect measurement because the driving torque prevails on the driven axle only.
[0010] It is furthermore preferred that the wireless transmission of the tire pressure values takes place by radio transmission by means of a radio transmitter and radio receiver or by way of an optical transmission by means of transmitting diode and receiving diode. It is also preferred that there is an on-wire transmission link for transmitting the tire pressure values between the radio receiver or the receiving diode, respectively, and the evaluating unit.
[0011] The central reception antenna is preferably arranged on the vehicle in such a manner that the individual transmitter devices are allocated to the respective vehicle wheels by way of the field strength or the intensity of the transmitted signal, respectively.
[0012] In a preferred embodiment of the tire pressure monitoring device of the invention, the tire pressure monitoring system with indirect measurement, in addition to the wheel speed sensors on the non-driven vehicle axle, includes another wheel speed sensor on the driven vehicle axle or on a wheel of the driven axle. All vehicle wheels include wheel speed sensors in a particularly preferred embodiment.
[0013] In another preferred embodiment, an additional tire pressure measuring device is arranged on the non-driven vehicle axle or, in the case of all-wheel driven vehicles, on another driven vehicle axle.
[0014] It is preferred to connect a driving dynamics sensor furnishing information about the yaw rate and/or the lateral acceleration of the vehicle, to the evaluating unit in addition to the tire pressure monitoring system with indirect or direct measurement, with the result that cornering maneuvers are detected safely and quickly. This leads to a more precise and faster pressure loss detection in the tire pressure monitoring system with indirect measurement.
[0015] The learning mode is preferably started by the actuation of a reset button, e.g. in the event of changing of tires. The reset button is actuated by the operator or a mechanic.
[0016] The invention further relates to a computer program product which comprises the method of the invention.
[0017] Further features of the invention can be taken from the subsequent description by way of five embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] The tire pressure monitoring device of the invention provides two tire pressure sensors, one per wheel, on the driven axle in a first embodiment. The non-driven axle is monitored by way of wheel speed sensors already provided e.g. in a vehicle equipped with an anti-lock system (ABS). This arrangement is advantageous because pressure loss on a driven wheel is safely detected. Due to driving of a wheel (e.g. during acceleration of the vehicle) the effect utilized in the tire pressure monitoring system with indirect measurement is frequently so insignificant that pressure loss can only be detected safely by a tire pressure monitoring system with direct measurement. In the non-driven axle, however, a tire pressure monitoring system with indirect measurement is appropriate to safely detect tire pressure loss. Each tire pressure sensor has a transmitting unit and a receiving unit fitted to the vehicle to supply information about the pressure value of the tire to an evaluating unit. This renders position detection possible, i.e. the allocation of the individual wheels to their installation positions (left front wheel, right front wheel, etc.). The influence of different coefficients of friction μ between tires and roadway has an effect on the driving wheels only because a rotational speed difference exists between a wheel at a high coefficient of friction μ high and a wheel at a low coefficient of friction μ low due to the torque applied to a driving wheel. Therefore, the tire pressure monitoring device described herein is able to safely and quickly detect an insignificant pressure loss even under so-called μ-split conditions (the wheels of the driven axle adopt different coefficients of friction). Different coefficients of friction may e.g. imply a high coefficient of friction μ high on dry asphalt and a low coefficient of friction Plow on an icy roadway. The non-driven wheels, however, do not depend on the coefficients of friction in terms of their rotational behavior. The result is that even insignificant tire pressure losses are safely and quickly detected by means of relatively low detection thresholds, in contrast to the relatively high detection thresholds in a conventional indirect tire pressure monitoring system according to the state of the art.
[0019] In contrast to the first embodiment, a central receiving unit for all transmitting units of the tire pressure sensors is used in a second embodiment. Position detection is also enabled thereby when the receiving unit is arranged in such a fashion, e.g. by being positioned more closely to a transmitting unit, that the wheels are allocated to their installation positions by way of the different field intensities of the transmitting units.
[0020] In a third embodiment, another wheel speed sensor is additionally used on the driving axle on a wheel of the driven axle or directly on the driven axle e.g. on the differential. This provision allows detecting a simultaneous pressure loss on both wheels of the non-driven axle, or a simultaneous pressure loss on all wheels. Position detection is herein possible as well by using the arrangement of the receiving unit(s) as described in the first and second embodiments.
[0021] In a fourth embodiment, the first embodiment described is supplemented to such effect that wheel speed sensors are employed on all wheels. Likewise in this embodiment, position detection is possible by using the arrangement of the receiving unit(s) described in the first and second embodiments. Further, this embodiment is favorable in that a fallback level detecting pressure loss on the individual tires exists due to the tire pressure monitoring system with indirect measurement even upon failure of the tire pressure monitoring system with direct measurement.
[0022] In a fifth embodiment, a tire pressure sensor is employed on a wheel on the non-driven axle in addition to the first embodiment. This provision allows detecting pressure loss more quickly.
[0023] The employment of driving dynamics sensors such as yaw rate sensor or lateral acceleration sensor allows further improving the above-mentioned embodiments because e.g. a cornering maneuver is safely detected by the driving dynamics sensors so that the monitoring times of the tire pressure monitoring system with indirect measurement are shortened.
[0024] The methods of monitoring the tire pressure are explained in the following by way of the above-mentioned embodiments. As a starting point, a vehicle with a driven front axle is examined, while the method of the invention is not limited to vehicles with a driven front axle. The wheels VL (left front) and VR (right front) are directly monitored by wheel pressure sensors. The wheels HL (left rear) and HR (right rear) are monitored by wheel speed sensors. The wheels HR (left rear) and HR (right rear) are monitored by wheel speed sensors. The wheel speed sensors measure the wheel speeds of the individual wheels HL and HR, the said wheel speeds being composed of the wheel rolling circumferences and the wheel revolution times T for a wheel rotation. Each wheel HL and HR has an individual wheel revolution time (T HL , T HR ).
[0025] According to the first embodiment, the tire pressure monitoring system with indirect measurement, after actuation of a reset button, learns a reference value X 1 ref on the basis of the two wheel speed sensors on the non-driven axle. This reference value X 1 ref is mainly based on a difference between the two wheel revolution times T HL and T HR of the wheels HL and HR under review, and the difference is divided by the sum of the two wheel revolution times T HL and T HR . The reference value X 1 ref is determined in consideration of difference vehicle speeds and in consideration of cornering maneuvers. After completion of this learning phase, a current comparison value X 1 current is constantly determined from the same wheel revolution times T HL and T HR according to the method described hereinabove. A difference is produced from the comparison value X 1 current and the reference value X 1 ref . This difference is compared with a threshold value S previously determined from the reference value X 1 ref or a threshold value −S, respectively. When this difference exceeds the threshold value S, or is lower than the threshold value −S, respectively, pressure loss on one of the wheels HL and HR can be precisely allocated to the respective wheel HL or HR. In this respect, it is important that the difference between the comparison value X 1 current and the reference value X 1 ref is produced only in the same driving situation, e.g. at the same vehicle speed and when straight travel is detected. In vehicles equipped with an electronic stability program (ESP), it is easily possible to evaluate the data of a yaw rate sensor or lateral acceleration sensor to procure information about a cornering maneuver.
[0026] According to the third embodiment, the tire pressure monitoring system with indirect measurement learns different reference values X 1 ref and X 2 ref by way of an additional wheel speed sensor, e.g. on the wheel VL of the driven axle. The reference value X 1 ref is determined like in the previous embodiment. The reference value X 2 ref is basically composed of the difference between the two wheel revolution times T HL and T VL , with the difference being divided by the sum of the wheel revolution times T HL and T VL . The reference value X 2 ref is learnt in different driving situations like the reference value X 1 ref . It does not matter in this arrangement, on which wheel of the driven axle the additional wheel speed sensor is arranged. The wheel speed sensor can also be arranged on the differential of the driven axle. The wheel speed sensor can also be arranged on the differential of the driven axle. This additional wheel speed sensor allows detecting stealthy pressure loss on the non-driven axle. Monitoring the non-driven axle takes place similar to the first embodiment. Only if a tire pressure sensor detects a pressure difference on the driven axle will a current comparison value X 2 current be produced corresponding to the reference value X 2 ref in consideration of the same driving situations. A difference between the current comparison value X 2 current and the reference value X 2 ref is produced. This difference is compared to a previously defined threshold value S 1 . If this difference is lower than the threshold value S 1 , there is a stealthy pressure loss on both wheels of the non-driven axle.
[0027] A complete indirect tire pressure monitoring system as described hereinabove prevails according to the fourth embodiment. This increases the fail-safety of the system further because a system according to one of the above-mentioned embodiments prevails upon failure of one or more of the wheel speed sensors. The non-driven axle is monitored in this arrangement like in the first embodiment. The driven axle is monitored similar to the non-driven axle. Stealthy pressure loss on a vehicle axle can be detected in addition by the method described in the third embodiment.
[0028] The other embodiments are not described in detail herein because the additional use of a tire pressure sensor with direct measurement achieves an obvious improvement in accuracy as the tire pressure value is directly provided. The mentioned embodiments are considerably improved in terms of shorter monitoring times or cornering detection by the additional use of further driving dynamics sensors, as has been described hereinabove. | Disclosed is a tire pressure monitoring device for a motor vehicle. A tire pressure monitoring system with direct measurement includes a transmission device for transmitting tire pressure values determined by pressure sensors, and a tire pressure monitoring system with indirect measurement that operates on the basis of wheel speed sensors. The tire pressure monitoring system with direct measurement includes a tire pressure measuring device for measuring a tire pressure value only on each wheel of a driven vehicle axle and on at most one wheel of a non-driven axle. The tire pressure monitoring system with indirect measurement includes wheel speed sensors on the non-driven vehicle axle. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to the application of hybrid cords comprising polyethylene terephthalate (PET) and nylon 6.6 multifilament yarns as cap ply reinforcement material in pneumatic radial tires which have high speed durability and low flatspot feature.
BACKGROUND OF THE INVENTION
[0002] It is known that reinforcement materials that are wound spirally with a small angle with the equatorial plane on the belt package especially improve the high speed performance in radial tires. Using polymeric (nylon 6.6, PET, aramide/nylon etc.) cords as cap ply reinforcement as strips has been applied for many years by several tire companies in order to improve high speed durability and handling performance in pneumatic radial tires. The said cord strips are obtained by cutting calendered (rubberized) cord fabric in strips or rubberizing parallel single cords in a certain width during extrusion process.
[0003] The purpose of using the cap ply reinforcement is to increase the high speed durability of the tire by avoiding belt layer separation caused by the centrifugal force occurring in the belt package at high speeds. Especially the intensity of the resistance shown by the tire against belt edge separations is highly important for high speed durability.
[0004] When the nylon is used as cap ply reinforcement material, there are two important disadvantages. First one is the obligation to be used as more than one layer due to its low modulus. And the second one is the temporary geometric deformation (flatspot) caused as a result of cooling the tire heated at high speed upon parking, since the glass transition temperature (Tg) of the polymer is low.
[0005] U.S. Pat. No. 7,584,774, an application known in the state of the art, discloses the use of high modulus polyethylene terephthalate cord as cap ply reinforcement material in order to increase the high speed durability of tire and decrease the temporary geometric deformation (flatspot) problem. In this embodiment wherein the tangent modulus of the cap ply cord is suggested being higher than 2.5 mN/dtex. % at 160° C. under 29.4N, there is a risk of the cords cutting the coating rubber during vulcanization process. For this reason it is suggested that the process expansion will be maximum 2%. Furthermore, the fatigue failure risk of polyethylene terephthalate cord, which has higher modulus than nylon 6.6 cord, under cyclic deformation is higher than nylon 6.6 cord.
[0006] German Patent documents no DE10201210.5766 and DE102007025490 known in the state of the art, disclose a strength support layer for elastomeric products and a pneumatic vehicle tyre which contains at least one strength support layer.
[0007] In order to increase the high speed durability of the tire, the cap ply reinforcement cords located on the belt package should resist the tire growth that can occur from the centrifugal force at high speed.
[0008] The said tire growth resistance formed in the cap ply reinforcement cords is comprised the total of
stress (cold residual tension) occurring in the cap ply reinforcement cords after vulcanization process, thermal shrink force generated due to increasing temperature of belt zone because of high speed, and the cord modulus at the said temperature.
SUMMARY OF THE INVENTION
[0012] The objective of the present invention is to provide a pneumatic radial tire comprising cap ply reinforcement.
[0013] Another objective of the present invention is to provide a pneumatic radial tire wherein the hybrid cords in cap ply reinforcement layer are comprised of polyethylene terephthalate (PET) and nylon 6.6 multifilament yarns.
[0014] A further objective of the present invention is to provide a radial tire reinforced with hybrid cord wherein the pressure on the belt cord is increased at high speed and temperature by increasing the thermal shrinkage force.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Pneumatic radial tire reinforced with hybrid cord developed to fulfill the objectives of the present invention is illustrated in the accompanying figures, in which:
[0016] FIG. 1 is the front sectional view of the inventive radial tire.
[0017] FIG. 2 is the perspective view of hybrid cord used as cap ply reinforcement layer
[0018] FIG. 3 is the definitions of Z and S twist directions of hybrid cords present in the cap ply reinforcement layer.
[0019] The components shown in the figures are each given reference numbers as follows:
1 . A pneumatic radial tire reinforced with hybrid cord 2 . Tire bead ring 3 . Carcass 4 . Tread 5 . Belt 6 . Cap ply reinforcement layer 61 . Hybrid cord 62 . PET multifilament yarn 63 . Nylon 6.6 multifilament yarn 7 . Belt edge reinforcement layer
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0030] The inventive pneumatic radial tire ( 1 ) essentially comprises at least one tread ( 4 ) forming the outermost layer of the tire ( 1 ) and at least one belt ( 5 ) on the carcass ( 3 ) forming the inner layer of the tire ( 1 ). The tire ( 1 ) is reinforced with at least one cap ply reinforcement layer ( 6 ) which is obtained by using hybrid cords ( 61 ) which are formed by twisting polyethylene terephthalate (PET) ( 62 ) and nylon 6.6 multifilament yarns ( 63 ) and the thermal shrinkage force and modulus of which are increased by applying heat-set process; therefore the high speed durability of the tire ( 1 ) is increased. The cap ply reinforcement layer ( 6 ) is between the tread ( 4 ) forming the outer layer of the tire ( 1 ) and the belt ( 5 ) formed of steel material. The cap ply reinforcement layer ( 6 ) is wound spirally on the belt ( 5 ) as strip such that it will for an angle between 0 and 5 degrees with the equatorial plane.
[0031] The heat-set process, which is a thermal process, comprises stretching hybrid cord ( 61 ) minimum 1% at 180-240° C. This process increases the tension value of the cord ( 61 ) corresponding to 3% level to minimum 8 mN/dtex at 25° C., and it increases the thermal shrinkage force above 2 mN/dtex at 177° C.
[0032] In heat-set process, the hybrid cords ( 61 ) are also provided with adhesive property with the rubber in the tire ( 1 ) by applying resorcinol formaldehyde latex (RFL) dip solution.
[0033] In the preferred embodiment of the invention, there is at least one belt edge reinforcement layer ( 7 ) wound on each side of the cap ply reinforcement layer ( 6 ) in order to support the cap ply reinforcement layer ( 6 ). Cap ply reinforcement layer ( 6 ) having hybrid cords ( 61 ) with increased thermal shrinkage force and wound on the belt ( 6 ) and the belt edge reinforcement layer ( 7 ) enable to increase high speed durability by providing resistance against the increase in diameter of the tire ( 1 ).
[0034] The hybrid cords ( 61 ) forming the cap ply reinforcement layer ( 6 ) are obtained by twisting pre-twisted PET ( 62 ) and nylon ( 63 ) yarns in Z or S direction such that they will be in reverse direction of the pre-twisting direction. The twisting level varies between 100 and 800 twists/meter, preferably 200 to 400 twists/meter. In the preferred embodiment of the invention, the twisting level of the hybrid cords ( 61 ) is equal to pre-twisting level of yarn or it has maximum 10% difference.
[0035] The width of the cap ply reinforcement layer ( 6 ) should be equal to the width of the belt ( 5 ) or it should be wider than the belt.
[0036] The width of the cap ply reinforcement layer ( 6 ) as strip which is used as wound around the belt ( 5 ) varies between 5 mm and 30 mm, preferably 8 mm to 15 mm. The number of cords ( 61 ) provided in 10 mm width of the cap ply reinforcement layer ( 6 ) can vary between 5 and 20.
[0037] The reinforcement layer ( 6 ) can exist in the tire ( 1 ) as coated with rubber or not coated with rubber. The linear densities* of the hybrid cords ( 61 ) in the cap ply reinforcement layer ( 6 ) are between 500 and 6000 dtex. In the preferred embodiment of the invention, the linear density of nylon 6.6 multifilament yarns ( 63 ) is smaller than the linear density of the PET multifilament yarns ( 62 ). In one embodiment of the invention, the linear density of nylon 6.6 yarns ( 63 ) forming the hybrid cord ( 61 ) is 1400 dtex, while the linear density of the PET yarns ( 62 ) is 1440 dtex. *The linear density is the weight of 10000 meters length of a yarn in unit of gram, and its unit value is dtex. | Pneumatic radial tire comprising a tread ( 4 ) forming the outermost layer of the tire ( 1 ) and at least one belt ( 5 ) on top of the carcass ( 3 ) forming the “inner layer” of the tire ( 1 ). As cap ply reinforcement layer ( 6 ) hybrid cords are applied comprising polyethylene terephthalate (PET) and nylon 6.6 multifilament yarns to provide a pneumatic radial tire having high speed durability and a low flatspot feature. | 3 |
REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This Patent Application claims priority under 35 U.S.C. § 119 to GB 0423398.7, filed on Oct. 22, 2004, 2005, titled, “BELT TENSIONING MECHANISM”, the full disclosure of which is hereby fully incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a belt tensioning mechanism for use in a forage harvester and comprising a cranking arm pivotable about a fixed axis between two positions and connected to move an idler roller into and out of contact with a belt to be tensioned.
BACKGROUND OF THE INVENTION
[0003] A forage harvester can be used with different crops, some with, and other without, kernels. As kernels are difficult for animals to digest, it is known to provide a kernel cracking device, sometimes also known as a crop processor, which can selectively be placed within and withdrawn from the crop flow path, to suit the crop being harvested (see for example EP-A-1358788). The crop processor typically comprises a pair of belt driven serrated rollers between which the crop is crushed. Because of the belt drive, withdrawal of the crop processor from the crop flow path requires removal of the drive belt and hitherto relieving the belt tension and removing the belt have proved to be difficult tasks for which tools were needed.
[0004] The problem is aggravated by the little space available in a forage harvester to accommodate the drive belt. Further, drive pulleys of the crop processor place severe limitations one where a belt tensioning mechanism can be accommodated.
[0005] Accordingly, the present invention seeks therefore to provide a belt tensioning mechanism that is sufficiently compact to enable it to be used in a forage harvester, yet which allows the belt tension to be released and reset rapidly without the need for special tools.
SUMMARY OF THE INVENTION
[0006] According to the present invention, there is provided a belt tensioning mechanism comprising a cranking arm pivotable about a fixed axis between two positions and connected to move an idler roller into and out of contact with a belt to be tensioned, a plate rotatable with the cranking arm and a spring biased locking lever cooperating with the plate to lock the cranking arm in each of the said two positions.
[0007] Conveniently, the idler roller is connected to a rod that is slidably connected to the cranking arm and at least one spring is provided to act between the cranking arm and a stop on the rod. In this way, the idler roller can be moved between two positions rapidly by rotating the cranking arm and in each of the two positions the cranking arm is firmly and securely locked.
[0008] Preferably, the locking lever includes a projecting pin, which engages in a respective one of two holes formed in the locking plate when the cranking arm is in each of the two positions. Of course, it would be possible to provide alternative interlocking formations on the locking lever and the plate. A locking lever is provided in the present invention because considerable force is required to release the locking pin because it is the pin, or other interlocking formation, which provides the reaction force needed to maintain the belt in tension.
[0009] Advantageously, the locking lever is pivotable about an axis that is coplanar with the axis of rotation of the cranking arm but extends transversely thereto. This makes for a particularly compact configuration. The stop on the rod may suitably be constituted by a nut in screw threaded engagement with the rod, the position of the nut along the rod being thereby adjustable to set the force applied by the idler roller to the belt to maintain the belt in tension.
[0010] Because of the space limitations mentioned above, it may not be possible to make the cranking arm sufficiently long to enable the desired degree of belt tension to be applied by manually the turning the cranking lever. It is therefore desirable to provide the cranking arm with a connector to enable an extension lever to be attached to the cranking arm. The connector may for example be a simple tube welded to the cranking arm to receive the end of a crow bar or other convenient implement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention will now be described further, by way of example, with reference to the accompanying drawings, in which:
[0012] FIG. 1 is a side view of a belt tensioning mechanism of the invention with the belt tension released;
[0013] FIG. 2 is a similar view to FIG. 1 with the belt tension applied; and
[0014] FIG. 3 is a perspective view from above of the belt tensioning lever mechanism for moving the rod connected to the idler roller.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] FIGS. 1 and 2 show a drive belt 10 for a crop processor of a forage harvester which passes around four pulleys 12 , 14 , 16 and 18 . A fuller description of this belt drive is to be found in EP-A-1358788, referred to above, and a detailed explanation is not required in the present context as the invention can be applied to any belt drive in which it is desired to be able to release the belt tension and reset it rapidly without the use of special tools.
[0016] In the case of the illustrated belt drive, it suffices to know that the pulley 18 is driven by the blower (not shown) of the forage harvester, pulley 12 is a first idler roller and pulleys 14 and 16 are drive pulleys mounted on the ends of the serrated rollers (not shown) of the crop processor. Tension in the belt 10 is maintained by a second idler roller 20 that is mounted on the end of a short pivotable arm 22 and is pulled against the belt 10 by the belt tensioning mechanism of the invention.
[0017] As shown in FIG. 3 , the belt tensioning mechanism includes a cranking arm 28 comprising a central hub 28 a and two radially projecting cheeks 28 b and 28 c which carry between them a guide block 26 that can pivot relative to the cheeks 28 b and 28 c about pins 26 a . A rod 24 that is connected to the arm 22 (see FIGS. 1 and 2 ) is slidably received in the guide block 26 . Two nuts 32 and 34 (see FIGS. 1 and 2 ) that are threaded on to the rod 24 act as end stops for a strong spring 36 and a weaker spring 38 arranged on opposite sides of the guide block 26 .
[0018] The cranking arm 28 is pivotably mounted on a stationary frame member 40 by means of a pin 42 passing through its hub 28 a . The cheek 28 b has welded to it a short length of tube 44 which can act as a connector for an extension lever, such as a crow bar. The opposite cheek 28 c is formed integrally with a plate 46 having two holes 48 . A locking lever 50 is pivotable relative to the frame member 40 about a pivot 52 of which the axis lies in the same plane as that of the pin 42 but at right angles to the latter axis. To one side of the pivot 52 , the locking lever 50 is acted upon by a spring mechanism 54 and on the opposite side it carries a pin 56 which can engage in the two holes 48 to lock the cranking arm in one of two positions.
[0019] By inserting a lever into the connector 44 , the cranking arm can 28 be turned manually between the position shown in FIG. 1 and that shown in FIG. 2 . When the cranking arm 28 is turned counter-clockwise to engage the pin 56 in one of the holes 48 of the plate 46 , the belt drive adopts the configuration shown in FIG. 1 . Here, the guide block 26 has moved to the right and the weak spring 38 acting on the stop 34 has moved the rod 24 to the right to disengage the idler roller 20 from the belt 10 . In this position, the belt 10 can be lifted off the various pulleys 12 , 14 , 16 , 18 , and 20 to enable the crop processor to be removed. The weak spring 38 is required only to be able to apply the necessary force to pivot the idler roller 20 and the arm 22 .
[0020] When the crop processor is re-introduced into the crop flow path, the belt 10 is rethreaded around the various pulleys 12 , 14 , 16 , 18 , and 20 . To tension the belt 10 , the locking lever 50 is first pivoted about the pivot 52 (see FIG. 3 ) to disengage the pin 56 (also see FIG. 3 ) from the hole 48 in the plate 46 . With the pin 56 retracted from the hole 48 , the plate 46 and the cranking arm 28 can be rotated clockwise into the position shown in FIG. 2 . An extension lever needs to be inserted in the connector 44 to allow sufficient torque to be applied to tension the belt 10 .
[0021] When the cranking arm reaches the position shown in FIG. 2 , the spring mechanism 54 (see FIG. 3 ) acting on the lever 50 pivots it to engage the pin 56 (also see FIG. 3 ) in the second hole 48 , in order to lock the cranking arm 28 in its new position. In this position, the guide block 26 has been moved to the left, as viewed, by the rotation of the cranking arm 28 and the spring 36 , which transmits a force to the rod 24 via the stop 32 to move the idler roller 20 into the belt tensioning position. The belt tension is controlled by the compression of the spring 36 , which can itself be adjusted by moving the nut 32 along the rod 24 . Once the position of the nut 32 has been set, the same degree of tension will be applied to the belt 10 whenever the cranking lever 28 is moved into the position shown in FIG. 2 .
[0022] It can thus be seen that the invention allows simple removal and replacement of the belt 10 without any special tools and ensures that the correct tension is applied to the belt 10 after it has been replaced. The entire operation can be carried out by single person who can turn the cranking arm 28 with one hand while releasing the locking lever 50 with the other. The length of the lever 50 simplifies the task of releasing the locking pin 56 and this operation is also made easier if the force on the pin 56 is reduced by turning the cranking arm 28 with the aid of the extension lever. | A belt tensioning mechanism for use in a forage harvester comprises a cranking arm pivotable about a fixed axis between two positions and connected to move an idler roller into and out of contact with a belt to be tensioned. A plate rotatable with the cranking arm cooperates with a spring biased locked lever to lock the cranking arm in each of the two positions. | 5 |
REFERENCE TO RELATED APPLICATION
[0001] This patent application claims priority under 35 U.S.C. § 119(e) to provisional patent application Ser. No. 60/603,329 entitled “Scissor Mechanism for a Latch Assembly,” which was filed on Aug. 20, 2004, the disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] Embodiments are generally related to latch mechanisms. Embodiments are also related to door latch systems utilized in vehicles such as automobiles. Embodiments are additionally related to automatic latching systems.
BACKGROUND OF THE INVENTION
[0003] Latching mechanisms (i.e., “latches”) are utilized in a variety of commercial and industrial applications, such as automobiles, airplanes, trucks, and the like. For example, an automotive closure, such as a door for an automobile passenger compartment, is typically hinged to swing between open and closed positions and conventionally includes a door latch that is housed between inner and outer panels of the door. The door latch functions in a well-known manner to latch the door when it is closed and to lock the door in the closed position or to unlock and unlatch the door so that the door can be opened manually.
[0004] The door latch can be operated remotely from inside the passenger compartment by two distinct operators—a sill button or electric switch that controls the locking function and a handle that controls the latching function. The door latch is also operated remotely from the exterior of the automobile by a handle or push button that controls the latching function. A second distinct exterior operator, such as a key lock cylinder, may also be provided to control the locking function, particularly in the case of a front vehicle door. Each operator is accessible outside the door structure and extends into the door structure where it is operatively connected to the door latch mechanism by a cable actuator assembly or linkage system located inside the door structure.
[0005] Vehicles, such as passenger cars, are therefore commonly equipped with individual door latch assemblies, which secure respective passenger and driver side doors to the vehicle. Each door latch assembly is typically provided with manual release mechanisms or lever for unlatching the door latch from the inside and outside of the vehicle, e.g. respective inner and outer door handles. In addition, many vehicles also include an electrically controlled actuator for remotely locking and unlocking the door latches.
[0006] Automotive latches are increasingly performing complex functions with fewer motors. For example, it is desirable to perform a variety of latch functions with only one motor. In such cases, increased accurate motor control systems and methods are required in order properly electrically actuate the latch and obtain the desired operation. In order to enhance latching operations, it is often necessary that the latch assembly components, such as sliders and spring portions, function with sufficient force to trigger latching operations using intermediary elements and parts such as, for example, toggle levers and so forth. Conventional latch assemblies typically lack the necessary forth to return sliders, for example, to their neutral positions, which can result in latch failure or at the very least, poor latch performance. It is believed that a solution to these problems involves the design and implementation of improved spring mechanisms utilized in latch assemblies.
BRIEF SUMMARY
[0007] The following summary of the invention is provided to facilitate an understanding of some of the innovative features unique to the present invention and is not intended to be a full description. A full appreciation of the various aspects of the invention can be gained by taking the entire specification, claims, drawings, and abstract as a whole.
[0008] It is, therefore, one aspect of the present invention to provide for an improved latch assembly.
[0009] It is another aspect of the present invention to provide for an improved slider return mechanism for use with such a latch assembly.
[0010] It is a further aspect of the present invention to provide for a scissor mechanism for controlling sliders utilized in a latch assembly.
[0011] The aforementioned aspects of the invention and other objectives and advantages can now be achieved as described herein. A scissor apparatus for a latch assembly is disclosed, which includes a spring comprising a plurality of fingers for controlling the motion one or more sliders associated with said latch assembly, wherein said spring comprises a spring control independent of the actuation of such sliders. The fingers are generally integrated with the spring. Such a one-piece spring can be implemented as a stamped component with 2-off, 3-off or 6-off fingers to control the motion of the sliders. The stamped spring can clip onto existing latch assembly components in order to promote retention, and overcome friction with the latch assembly and return the sliders to a neutral position thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the present invention and, together with the detailed description of the invention, serve to explain the principles of the present invention.
[0013] FIG. 1 illustrates a perspective view of a vehicle door mounted to a passenger vehicle in which a preferred embodiment can be implemented;
[0014] FIG. 2 illustrates a latch assembly, which can be adapted for use with the passenger vehicle depicted in FIG. 1 ;
[0015] FIG. 3 illustrates a conventional latch assembly, including conventional sliders and a conventional spring and retention pin for use therewith;
[0016] FIG. 4 illustrates a conventional slider actuation problem;
[0017] FIG. 5 illustrates a portion of a latch assembly including a scissor mechanism, in accordance with one embodiment;
[0018] FIG. 6 illustrates a perspective view of a latch assembly, which can be implemented in accordance with one embodiment;
[0019] FIG. 7 illustrates an exploded view of a portion of the latch assembly depicted in FIGS. 5-6 , in accordance with one embodiment;
[0020] FIG. 8 illustrates a portion of a perspective view of the latch assembly depicted in FIGS. 5-7 , in accordance with one embodiment;
[0021] FIG. 9 illustrates actuation of the scissor mechanism depicted in FIGS. 5-8 , in accordance with one embodiment;
[0022] FIG. 10 illustrates the lower half of a latch assembly incorporating a scissor spring, in accordance with a preferred embodiment;
[0023] FIG. 11 illustrates a perspective view of the scissor spring of FIG. 10 mounted on a latch assembly, in accordance with a preferred embodiment;
[0024] FIG. 12 illustrates a perspective view of the scissor spring depicted in FIGS. 10-11 , in accordance with a preferred embodiment;
[0025] FIG. 13 illustrates scissor spring actuation, in accordance with a preferred embodiment;
[0026] FIG. 14 illustrates a scissor spring, which can be implemented in accordance with an alternative embodiment; and
[0027] FIG. 15 illustrates a detailed view of a group of sliders that can be incorporated into a single piece scissor spring, which is independent of the control of slider actuation, in accordance with an alternative embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment and are not intended to limit the scope of the invention.
[0029] FIG. 1 illustrates a perspective view of a vehicle door 13 mounted to a passenger vehicle in which a preferred embodiment can be implemented. A vehicle, such as an automobile can be equipped with one or more individual door latch assemblies 11 , which secure respective passenger and driver side doors to the vehicle 15 . Each door latch assembly 11 is typically provided with manual release mechanisms or lever for unlatching the door latch from the inside and outside of the vehicle, e.g. respective inner and outer door handles.
[0030] In addition, many vehicles can also be equipped with electrically controlled actuators for remotely locking and unlocking the door latches. As indicated in FIG. 1 , a door latch assembly 11 can be mounted to a driver's side vehicle door 13 of a passenger vehicle 15 . The door latch assembly 11 may be mounted to front and rear passenger side doors thereof and may be incorporated into a sliding side door, rear door, a rear hatch or a lift gate thereof, depending upon design constraints.
[0031] FIG. 2 illustrates a latch assembly 200 , which can be adapted for use with the passenger vehicle 15 depicted in FIG. 1 . Latch assembly 200 can be integrated with and/or adapted for use with door latch assembly 11 depicted in FIG. 1 . Latch assembly 200 includes a scissor spring 1202 , which is explained in greater detail herein with respect to FIGS. 10-15 .
[0032] FIG. 3 illustrates a conventional latch assembly 300 , including conventional sliders 302 , 304 , 306 and a conventional spring 308 . Sliders 302 , 304 , 306 and spring 308 are generally located between a metal plate 320 and a metal plate 323 , which are maintained by one or more posts 322 . Note that in FIGS. 3-4 , identical or similar parts or elements are generally indicated by identical reference numerals.
[0033] FIG. 4 illustrates therefore a conventional slider actuation problem associated with sliders 302 , 304 , 306 and spring 308 and retention pins 310 . In the illustration of FIG. 4 , arrow 324 generally refers to slider actuation. In the configuration depicted in FIG. 4 , sliders 302 , 304 and/or 306 have difficulty returning to their neutral position(s) and in some instances do not travel far enough to activate any associated toggle levers or pawl. One of the problems associated with the mechanism depicted in FIG. 4 is that slider 302 , 304 and/or 306 can become jammed after independent actuation and does not return to its neutral position, which is shown in FIG. 3 .
[0034] The spring mechanism, depicted in FIGS. 3-4 which includes spring 308 and retention pin 310 is mounted incorrectly, which generally causes sliders 302 , 304 , and/or 306 to tilt at an angle during their respective transfer functions, thereby reducing their effective travel. Their return travel is therefore intermittent due to the angle of the slider, which causes the slider to bind in its guide path due to the tangential force of the spring leg on spring 308 . Thus, the force of spring 308 is insufficient to overcome the friction within the latch assembly 300 thereof to return the sliders 302 , 304 , 306 to their respective neutral positions.
[0035] FIG. 5 illustrates a portion of a latch assembly 500 including a scissor mechanism thereof, in accordance with one embodiment. FIG. 6 illustrates a perspective view of latch assembly 500 , in accordance with one embodiment. Similarly, FIG. 7 illustrates an exploded view of a portion of latch assembly 500 depicted in FIGS. 5-6 , in accordance with one embodiment. FIG. 8 illustrates a portion of a perspective view of the latch assembly 500 depicted in FIGS. 5-7 , in accordance with one embodiment. FIG. 9 illustrates actuation of the scissor mechanism 409 depicted in FIGS. 5-8 , in accordance with one embodiment. Note that in FIGS. 5-9 , identical parts are indicated generally by identical reference numerals.
[0036] Latch assembly 500 is similar to latch assembly 300 discussed earlier, but differs from the latch assembly 300 in that latch assembly 500 incorporates scissor mechanism 409 , which is generally composed of a scissor retention pin 408 . Scissor mechanism 409 additionally includes a first scissor arm 404 , which is located above a spring 402 , which in turn is located over a second scissor arm 414 . Scissor mechanism 409 also includes a circle clip 412 that engages scissor retention pin 408 . Scissor mechanism 409 can be composed of 5 -off parts, a spring 402 , two arms 404 , 414 (i.e., identical in design, reverse mount to give opposite hand), circle clip 412 and scissor retention pin 408 . Spring mechanism 409 scissor arms 404 and 414 can be rotated during a transfer function of sliders 302 , 304 or 306 associated with latch assembly 500 . An example of such sliders is shown in greater detail herein with respect to FIGS. 14-15 . The configuration depicted in FIGS. 5-9 thus eliminates the problems of sliders binding. The scissor retention pin 408 can be configured to incorporate an abutment to prevent the scissor arms 404 , 414 and spring 402 from rotating fully during a slider transfer function. During a slider transfer function, only one of the scissor arms will rotate as they are both dependent on the travel direction of the sliders. During a typical transfer function, for example, a slider can act against a scissor arm, which in turn rotates and torques spring 402 as it acts against the other scissor arm. This scissor arm will be restricted from rotating as it acts against the abutment on the retention pin 408 . Once the transfer function is complete, the spring force will return the scissor arm and slider to a neutral position.
[0037] FIG. 10 illustrates the lower half of latch assembly 200 incorporating a scissor spring 1202 , in accordance with a preferred embodiment. FIG. 11 illustrates a perspective view of the scissor spring 1202 of FIG. 10 mounted on a latch assembly, in accordance with a preferred embodiment. FIG. 12 illustrates a perspective view of the scissor spring 1202 depicted in FIGS. 10-11 , in accordance with a preferred embodiment. FIG. 13 illustrates scissor spring actuation, in accordance with a preferred embodiment. Note that in FIGS. 2 and 10 - 13 , identical or similar parts or elements are generally indicated by identical reference numerals. In FIG. 13 , for example, scissor spring actuation is indicated generally by arrows 1302 , 1304 , 1306 , 1308 , 1310 and 1312 .
[0038] FIG. 14 illustrates a one-piece scissor spring 1400 , which can be implemented in accordance with an alternative embodiment. FIG. 15 illustrates a detailed view of a group of sliders 1410 , 1412 , 1414 that can be adapted for use with single piece scissor spring 1400 , which is independent of the control of slider actuation, in accordance with an alternative embodiment. Note that in FIGS. 14-15 , identical or similar parts or elements are generally indicated by identical reference numerals. The one-piece scissor spring 1400 includes one or more spring fingers 1404 , 1406 , 1408 , 1405 and so forth. Spring 1400 also includes a spring portion 1402 , which is generally rectangular in shape.
[0039] Actuation of the one-piece scissor spring 1400 is generally indicated by arrows 1502 , 1504 , 1506 , 1508 and 1510 in FIG. 15 . The concept of a one-piece scissor spring 1400 was developed in order to aid in latch assembly production. Spring 1400 can, for example, be implemented as a stamped component with 2-off, 3-off or 6-off fingers (e.g., fingers 1404 , 1406 , 1408 , 1405 , etc) to control the motion of sliders 1410 , 1412 and/or 1414 . Such a stamped spring 1400 can clip into existing components within a latch assembly, such as, for example, latch assembly 200 , in order to gain retention.
[0040] The various latch assemblies discussed herein, including components such as the one-piece scissor spring 1400 , can be utilized not only in the context of automobiles and vehicles, but can be utilized with any automotive latch system. Examples of such latching systems include aircraft engines and associated systems, propulsion systems, navigation systems, air force avionic systems, aerospace electronics, auxiliary power systems and aircraft landing systems. The one-piece scissor spring 1400 can, for example, be adapted for use with latch assemblies involving a single motor to effect a number of independent electrical actuations, such as, for example, central locking, super locking, selective locking, power/electrical door opening (passive opening) and/or power/electrical door closing (soft closing). Latch assemblies can be adapted for securing any type of closure (side doors, trunks, rear doors, sing or sliding doors, etc) and can be designed to fit into any type of vehicle.
[0041] The embodiments and examples set forth herein are presented to best explain the present invention and its practical application and to thereby enable those skilled in the art to make and utilize the invention. Those skilled in the art, however, will recognize that the foregoing description and examples have been presented for the purpose of illustration and example only. Other variations and modifications of the present invention will be apparent to those of skill in the art, and it is the intent of the appended claims that such variations and modifications be covered.
[0042] The description as set forth is not intended to be exhaustive or to limit the scope of the invention. Many modifications and variations are possible in light of the above teaching without departing from the scope of the following claims. It is contemplated that the use of the present invention can involve components having different characteristics. It is intended that the scope of the present invention be defined by the claims appended hereto, giving full cognizance to equivalents in all respects. | A scissor apparatus for a latch assembly is disclosed, which includes a spring comprising a plurality of fingers for controlling the motion one or more sliders associated with said latch assembly, wherein said spring comprises a spring control independent of the actuation of such sliders. The fingers are generally integrated with the spring. Such a one-piece spring can be implemented as a stamped component with 2-off, 3-off or 6-off fingers to control the motion of the sliders. The stamped spring can clip onto existing latch assembly components in order to promote retention, and overcome friction with the latch assembly and return the sliders to a neutral position thereof. | 5 |
BACKGROUND OF THE INVENTION
The invention relates in particular to the scanning technique based on ultra-sound according to the impulse-echo principle. This technique is generally performed in one of two possible manners.
The first is the use of the socalled B-scanning, which normally implies the scanning of a sectional plane through the object and a running registration of the positions of reflecting structures in the said sectional plane. The result is that after a few minutes of scanning it will be possible to have drawn up a two-dimensional picture on a storage-oscilloscope, showing the intersections of the reflecting structures with the sectional plane.
The second is the use of socalled dynamic scanning, which implies a rapid scanning of a limited area permitting utilization of the short-time memorizing of the eye for the formation of a picture.
B-scanning by way of a storage-oscilloscope represents the most widely used procedure, but it has a major drawback in that it takes a long time to draw up a satisfactory picture. It is accordingly required to form the entire picture before it is possible to see whether it is satisfactory, and then to wipe it off again entirely to adjust amplification etc.m before the next picture is registered. In the meantime, however, the conditions to be examined may have changed.
This may, for instance, be the case, if we are dealing with a fetus, which is moving. If we examine parts of the human body we have moreover no clear impression of the relation of the sectional picture to the body, as picture and body are placed at some distance from each other.
Dynamic scanning represents a more recent method, which in certain relations offers improvement in comparison with the B-scanning. Due to the rapid, automatically repeated scanning it is easier to make adjustments to obtain a better picture, as it will be possible to detect alterations instantly. Nor will there be any problems with regard to alterations of the conditions of the examined object, as it will be possible to ascertain such alterations directly during the scanning.
In spite of these improvements of the manner of producing the scanning pictures, there will still remain two problems unsolved:
1. You will only get a picture answering the section of the body being examined, which will complicate the formation of a picture of the entire spatial form and extent of a given structure.
2. You will have no direct idea of the position of the the examined body reproduced. Alterations of the scanning angle and position will bring about a change of the picture, but due to the appearance of the picture on a stationary screen, no particularly good impression of the position of a depicted structures is left.
SUMMARY OF THE INVENTION
It is the object of the invention to remedy these two disadvantages, and the method is characterized in that the indications by means of an arrangement of one or more mirrors is shown as imaginary luminous points placed preferably in exactly the position in an object, where a reflecting structure is actually found.
In this way the latter drawback has been overcome. The said method can be realized in many different ways by means of one or several mirrors, and it has proved possible by way of several of the possible embodiments to overcome the former drawback as well.
The invention relates likewise to an apparatus for the performance of the method, which said apparatus is provided with a transmitter for e.g. ultrasound or radar, made to emit impulses out along the first line and to receive the reflected echos along the same line, and to indicate the reflections as luminous points along the second line. The said apparatus is characterized by having between the two lines reflecting media for the formation of the imaginary picture. By the use of such media it is possible in a simple manner to form the desired picture, although it might even be imagined that the picture was formed for instance by way of optical and electronic devices.
An advantageous embodiment of the said apparatus is characteristic by providing devices for forward and backward swinging in one plane of the first line i.e. the line along which the impulses are emitted and the reflections received, and by having devices for the swinging of the second line either direct or in the form of a mirror image synchronous with the former. Thus in an uncomplicated manner, an idea of the echo-producing structures situated in a definite section is rendered and be it noticed to have the said section placed as an imaginary picture in a correct way in relation to the object being examined. By moving the apparatus sideways in relation to the plane in which the swinging takes place it will be simple to scan for a certain echo-producing structure in the object under examination.
A further embodiment is characteristic in that it has a stationary film camera in the room intended for long-time exposures. By likewise having the examined object stationarily placed in the room it will thus be possible to scan a certain area of the object and hereby attain a summing up in the film camera of the generated indications. It should in this connection be pointed out that it is relatively immaterial how the apparatus is moved within the searched area, as the said picture will appear distinct if only the requirement that camera and object area stationarily placed during the exposure is complied with.
A particularly advantageous embodiment of the apparatus concerned is characteristic in that it is made for the filming of three-dimensional pictures by way of stereo-technique. This leaves the possibility by studying the resultant three-dimensional picture to have a spatial impression of the echo-producing structures in position to each other, which means an impression of the distances between the echo-producing structures within the object.
Another similar embodiment is characteristic by having a stationary television camera stationarily placed in the room coupled with a storage oscilloscope in such a manner that the pictorial information is summed up. This offers principally the same advantage as the use of a stationary film camera but moreover a further advantage permitting a rapid wiping off of the appeared picture and allowing the study of the picture during the formation. Another embodiment of the latter apparatus can in a like manner be characteristic in that the camera is intended for the filming of three-dimensional pictures by way of stereo-technique. Hereby is achieved an entirely special effect allowing the study of the spatial picture during its formation and hence to conduct the transducer to the place where it must be relevant to have produced the spatial structure of special interest.
The apparatus may further be characterized by a programme-guided unit, devised for production of an even scanning pattern. Production of an even scanning pattern is of importance to the quality of the picture, just as it is important to a photograph to secure a uniform exposure of the individual sectors of the picture to reproduce a correct impression of the contrasts in the picture.
The embodiment of the apparatus described above can be characterized in that the devices for the production of the swings are made to swing at a frequency sufficient high for retaining the impression of light on the retina of the human eye, as the apparatus is constructed for work with impulse repetition frequencies considerably higher than the swinging frequency. It is in this way possible in a more safe manner to obtain an impression of the positions of the echo-producing structures in a certain section, as the entire section may constantly be studied in the form of constant luminous points in the place where the echo-producing structure remains.
Another embodiment for the achievement of the same effect is characteristic in having media for plotting of the indications of the second line on a storage display e.g. in the form of a LCD-display (liquid crystals), a storage oscilloscope or on magnetic paper, and having possibilities for preservation of the said indications on the display for a period equal to at least the time passing between two successive swings. By way of the mentioned embodiment it is possible to perform the said swingings at a lower frequency than the one required for the maintenance of impressions of light on the retina of the human eye, whereby it is avoided to strain the swinging mechanical parts so much.
A third embodiment for the attainment of the same optical impression as far as the study of the individual section concerns, is characterized by the means for swinging of the first line at a certain initial frequency, means for reading of the received echoes with corresponding distances in a buffer-memory, means for swinging of the second line at a certain second frequency higher than the former and sufficiently high to retain the impressions of light on the retina of the human eye, and means for repeated transmission of the indications of light from the buffer-memory to a series of light indicators along the second line synchronous with the movement of the latter.
This may bring about the further advantage of sparing mechanical parts which would otherwise swing at higher frequency.
An over-all general embodiment applicable in connection with all other embodiments of the apparatus consisting in a support of transmitter, receiver and mirror arrangement is characterized in that the support is mounted on a connecting rod mounted longitudinally displaceable in a stationary cardan suspension. Some of the weight of these parts is thus in a simple manner transferred to the firm support, which makes it easier to handle the apparatus in connection with the examination for example of a person. It is furthermore achieved that the mirror will always remain in a convenient position relative to the memorizing of the picture (camera or eye).
An apparatus of the said description, provided with a holder for a number of lamps or light indicators may further be characterized by the arrangements shown in FIGS. 8 and 9. Thus it is avoided to perform a swinging of the said light indicators with the appertaining wires, which represent a noticeable mass compared to the mirror, which is now instead swinging forwards and backwards at a frequency equal to at least 16 oscillations per second. The reduction of the swinging mass will, at the same time, mean, that the apparatus as such will only offer insignificant shaking. It has moreover proved more agreeable to look down into a stationary mirror.
An embodiment of the apparatus provided with a holder for a number of lamps or light indicators can be characterized by a first mirror, a transducer, made to swing round a first axis, a second axis, parallel with the first axis, and which in relation to the first axis is placed symmetrically round the plane of the first mirror, an indicator row, made to swing round the other axis in such a manner that the reflected picture in the other mirror, passing through the second axis, is situated symmetrically with the first line round the plane of the first mirror, as the reflecting faces of the mirrors are turned against each other.
The result is a very compact construction, and the swinging parts will be made to swing in opposition, whereby they will outbalance each other to a certain degree.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in detail below with reference to the drawing in which
FIG. 1 shows an embodiment of an apparatus according to the invention, viewed schematically from one side, and in which the apparatus is applied for examination of a person lying on his back,
FIG. 2 shows another embodiment of the apparatus according to the invention, viewed schematically from the end, and in which the apparatus is applied for scanning in a soft body,
FIG. 3 shows a third embodiment of the apparatus,
FIG. 4 shows an arrangement of mirrors, viewed from one side, of an apparatus according to a fourth embodiment,
FIG. 5 shows an arrangement of mirrors, viewed from the side according to a fifth embodiment,
FIG. 6 shows a sixth embodiment of the invention from a side view,
FIG. 7 shows a seventh embodiment of the invention from a side view,
FIG. 8 shows an eigth embodiment of the invention from a side view,
FIG. 9 the embodiment shown in FIG. 8, viewed schematically from the end, and
FIG. 10 an arrangement of mirrors seen from in front of an apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a lying person 1, viewed from one side, having an inner organ 2, which is to be examined by means of ultra-sound. A stationary arrangement 3 serves as support for a stereo camera 4, which may be a film camera or a television camera, and for a connecting rod 5 mounted longitudinally displaceable in a cardan suspension 6 of the support 3. On the connecting rod 5 is mounted a mirror 7, the reflecting surface of which is turning upwards. At the end of the rod 5 is mounted a pivot-hung holder 8 for a number of lamps or light-diodes 9. The holder 8 is designed to swing in a plane perpendicularly on the plane of the mirror 7, and which may possibly pass through the connecting rod 5. On the opposite side of the plane of the mirror 7 is, in a similar manner suspended, a pivot-hung transmitter and receiver 10 for ultra-sound made for the transmission and reception of ultra-sound along a line 11, pivoting symmetrically with the row of lamps 9 round the plane of the mirror 7. The transmitter 10 and the holder 8 are each mounted on gears or toothed rims 12 and 13 in mesh. The transmitter 10 and the row of lamps 9 are moreover mutually connected by means of known electronic means (not shown) in such a manner that the row of echoes along the line 11 are reproduced along the row of lamps 9 in such a way that at any time lighted lamps are placed symmetrically with respect to the corresponding echo producing structure around the plane of the mirror. Thus, as seen from the camera 4 in the mirror, will appear a non-inverted mirror-image of the echoes of the positions, from where they appear. In the rod 5 there is between the mirror 7 and the holder 8 or the transmitter 10, a built-in charnier 14 with an axis perpendicularly on the plane of the mirror 7.
The apparatus will now function in the following way: When the rod 5 with the mounted parts is moved forwards and backwards or sideways, there will be seen in the mirror 7, from the stationary position of the camera 4, gleams from the inner organ 2 precisely corresponding to points, which are echo-producing. This will also be the case, if the scanning takes place by way of a swinging of the holder 8 and the transmitter 10 towards each other or apart from each other and probably also round the charnier 14. By reproducing all the echoes during a three-dimensional scanning on, for instance, the same photographic plate in a stereo-camera, that is leaving the shutter of the camera open during the entire scanning process, it will be possible to produce a three-dimensional picture of the echo-producing structures in the inner organ. The only condition is that the inner organ 2 and the camera 4 remains in a fixed position mutually during the scanning. Instead of a photographic camera, a television camera with a pictorial memory and a viewer may advantageously be used. In this way it is possible, during the scanning process, to guide it in such a manner that the desired pictures are produced. It is moreover possible at any time to wipe off the received signals and start afresh.
Similarly, other information storage devices 4a may be used as a means to record the reflected images and to develop a pictorial view of the ultrasonic echoes. The storage device 4a could be a LCD - display (liquid crystals), a storage oscilloscope or a magnetic paper. The storage device 4a would have the capability of preserving the reflected image of the display of luminous points for a period equal to at least the time passing between two successive swings. Through the use of such a storage device, it allows the holder 8 to swing at a frequency below what would be required to retain an image on the human retina and, therefore, avoid unnecessary mechanical strain on the apparatus.
The apparatus may be further provided with a program-guided unit 5a which will insure an even scanning pattern. Even scanning is important to insure that a high quality picture is attained. Uneven scanning would result in point exposures on a photographic film or television camera which would not properly correspond to the actual echo produced.
An other method to determine where and how the pictures shall be taken is to study the picture with the human eye simultaneously with the rapid scanning movements.
FIG. 2 shows schematically another embodiment of an apparatus according to the invention. A holder 14 for a number of lamps 15 is coupled pivotably to a mirror 16 and to a transmitter and receiver 17 for ultra-sound, which is mounted on a plate 18 formed like a circle segment. A (not shown) motor is designed for bringing this plate 18 with the transmitter 17 in an oscillating movement as shown by the arrows A and B, simultaneously as the mirror 16 is exposed to a similar movement as shown by the arrows C and D, but all the time with an angular deflection half as great. In this manner a scanning of a body 19 can be performed within the angle determined by the swinging movement of the transmitter 17. The latter embodiment is distinguished by a simple construction, as it is possible to to hold the apparatus manually in the holder 14, while the remaining parts are moving. The lamps 15 are thus stationary, while in the swinging mirror is reflected a correctly situated picture provided the oscillating movement is of a frequency equal to at least 16 fields (oscillations) per second.
FIG. 3 shows likewise schematically an apparatus for ultra-sound examinations. This apparatus is constructed to perform a synchronously oscillating movement of a holder 20 for a row of lamps 21 and a transmitter 22, as shown by the arrows E and F, G and H, I or J, whereas a mirror 23 is fixed in relation to the swinging parts mentioned. The synchronous movement is produced by mounting the holder 20 and the transmitter 22 each on a cogged link, 24 and 25 respectively. By this construction the centre of rotation 26 will come close to the contact point 27 required for examinations with ultra-sound of a firm, or deformable body 28, for instance the body of an animal. Thus a good contact is attained. The swinging holder 20 with the lamps 21 lighting at different times will produce a laterally reversed picture when viewed direct. If on the other hand the picture is seen in the mirror the result will be a non-inverted correctly situated picture.
FIG. 4 shows schematically a transducer 40 bearing against a body 41 containing an echo-producing structure 42. The first line 43 along which the impulses are emitted is placed end to end with the second line 44, along which are placed indicator lamps 45. Perpendicularly on the said joint line (43,44) is placed a mirror 46 with upward-turned reflecting face. The indicator lamps 45 are now mutually situated in such a manner that an echo from a given point will produce an imaginary luminous spot on the very place, when seen down in the mirror as indicated by the shown sight lines.
FIG. 5 shows schematically a transducer 50 bearing against a body 51 containing an echo-producing structure 52. The first line 53, along which the impulses are emitted is crossing the second line 54, along which the indicator lamps 55 are placed. A mirror 56 is placed in the plane of symmetry of the two lines, as, however, the distance from the mirror to respectively transducer 50 and indicator lamps 55 may be varied through a displacement link 57 of a connecting rod 58, for instance through a swinging forward/backward translatory movement. The mirror 56 is moreover fixed at a certain distance from a firm point 59. If this distance is small we can be certain that the examined part of the body 51 can be covered by the mirror most of the time.
FIG. 6 shows schematically a transducer 60 bearing against a body 61 containing an echo-producing structure 62. The first line 63, along which the impulses are emitted, forms an angle v + 1/2 v = 11/2 v to a plane mirror 66 with a downward-turned reflecting face. The second line 64, along which the indicator lamps 65 are placed, is situated in a plane (plane of the paper) perpendicular on the plane of the mirror 66 containing the first line 63. The second line 64 forms at the same time an angle 1/2 v to the plane of the said mirror in the plane of the paper. Another mirror 67 having an upward-turned reflecting face is eventually placed perpendicularly on the plane of the paper and contains the second line 64. By adapting the indicator lamps in a suitable way it is now possible to attain a radiation pattern, as shown, which gives a highly compact construction of the apparatus.
FIG. 7 shows a transducer 70 bearing against a body 71 containing an echo-producing structure 72. The first line 73, along which the impulses are emitted, is placed end to end with the second line, along which the indicator lamps 75 are situated. Perpendicularly on the line 73 are placed mirrors 76 and 77 with the reflecting surfaces facing each other.
By adapting the indicator lamps and the mirrors in a suitable way it is possible to attain a radiation pattern as shown, and a compact construction will be the result.
FIGS. 8 and 9 should be considered together. An ultra-sound transducer 80 is designed to tip up and down or swing forwards and backwards round an axis O 1 , as an angle v 1 to the longitudinal axis L of the apparatus will then vary within the area by ±30°. A mainly triangular first mirror as shown in FIG. 8, and shown as a line in FIG. 9 is made to tip forwards and backwards round an axis O 2 in tact with the transducer 80, the following requirements, however, being complied with. The axis O 2 being parallel to the axis O 1 , and the angle v 2 , which the mirror 81 form to a plane perpendicular on the longitudinal axis L must at any time be half as great as the angle v 1 . A second mirror 82 situated perpendicularly on the longitudinal axis L is situated below the first mirror 81 right in the middle between the axes O 1 and O 2 . Finally, 83, indicator lamps are situated on the longitudinal axis L in a suitable manner, the following requirements being complied with. The distance l 1 between the axis O 1 and the surface of the transducer 80 is equal to the distance l 2 between the axis O 2 and the indicator lamp corresponding to the surface of the transducer. Hereafter the other parameters are adjusted to each other in such a manner that the echo-producing structure is depicted as a luminous spot in the form of an imaginary picture of the corresponding light indicator in a point, where the structure is placed. By having the mirror and the transducer swing at a frequency equal to at least 16 oscillations fields per second it will be possible hy looking down into the mirror to have a standing picture of a section of the body under examination. This embodiment can likewise with advantage be applied in connection with a stationary stereo-camera, just as previously described in relation to other embodiments.
FIG. 10 shows an apparatus consisting of a swinging transducer 100 bearing against a body 106 containing an echo-producing structure 107. The first line 105, along which the impulses are emitted, is swinging with the transducer 100 round a first axis O 3 . An indicator row 103 is designed to swing round a second axis O 4 running parallel to the first axis O 3 , and in relation to the former is situated symmetrically round a first mirror 101 with an upwards turning reflecting face. A second mirror 102 with a downward-turned reflecting face is situated through the second axis O 4 in such a manner that a mirror image 104 of the indicator row 103 at any time will be situated so that it is symmetrical with regard to the first line 105 round the mirror 101, as it appears from the shown radiation pattern. The second mirror 102 can be stationary relative to the first mirror 101, but it may also be adjustable in relation to the latter. It should be noted, however, that an embodiment could be practicable with both a swinging indicator row and a swinging mirror, with the movements of these mechanical elements coupled together in a suitable manner. For instance could be imagined an indicator row performing a sinus shaped movement coupled together with a mirror made to swing in such a manner that the angular velocity of the reflected picture will be numerically constant. | A method and apparatus for facilitating examination of an object within an optically opaque body through the use of impulse-echo techniques by projecting to an observation point, via a reflective surface positioned to intersect a line between the observation point and the object to be examined, a virtual image of a linear array of luminous points corresponding to echo-producing points of the object, such that each luminous point of the reflected image appears at a location, relative to the observation point, that coincides with the actual location of the corresponding echo-producing point of the object in the body. | 6 |
FIELD OF THE INVENTION
[0001] This invention pertains to olefins having a terminally disposed fluorocyclobutyl ring bearing an ionic functionality or a precursor thereto, a process for the production thereof, and polymers, especially ionomers, formed therefrom. The invention further pertains to ionically conductive compositions formed by the combination of a liquid and the ionomer of the invention, and electrochemical devices such as electrodes, sensors, and solid polymer electrolytes comprising those conductive compositions. The polymers of the invention are useful in the formation of films and coatings with high chemical resistance and good physical properties. The ionomers of the invention are useful in electrochemical applications, particularly in lithium batteries. The polymeric compositions of the invention are useful for strong acid catalysis, such as Friedel-Crafts alkylation.
BACKGROUND OF THE INVENTION
[0002] Barrick (U.S. Pat. No. 2,462,347) discloses the 2+2 cycloaddition of fluorinated ethylene whereof at least two of the hydrogens have been replaced by halogens of which at least two must be fluorines, to dienes having two terminally unsaturated bonds of which at least one must be ethylenic to form a fluorocyclo-butyl-containing terminal vinyl monomer. Conjugated dienes are preferred. Polymerization, or copolymerization with other unsaturated polymerizable compounds, is carried out in a free radical initiated process.
[0003] Glazkov et al., (Izvest. Akad. Nauk SSSR, Ser. Khim. 10, 2372ff, Oct. 1988) disclose the 2+2 cycloaddition of fluorovinyl ethers to conjugated dienes, particularly 1,3-butadiene and 1,3-pentadiene the reaction occurring at the terminal, rather than the internal, double bond of the pentadiene. Reactants included fluorovinyl ethers of the general formula R F OCF=CF 2 , wherein R f is CF 2 CF(CF 3 )O(CF 2 ) 2 SO 2 F. Synthesis of the cycloadduct was carried out at 120-140° C. for 6 hours in an autoclave. At temperatures above 150° C. and pressures of 5-10 kbar, the cyclic dimers of the fluorvinyl ethers were formed. Glazkov is silent regarding polymerization.
[0004] Roberts et al., (Organic Reactions, Vol. 12, Chapt 1, A. C. Cope, Ed. in Chief, John Wiley & Sons, Inc. New York, 1962) disclose conjugated dienes as highly reactive among unsaturated compounds in cycloaddition reactions with fluoroalkenes; unconjugated dienes are not mentioned. Similarly, Hudlicky (Chemistry of Organic Fluorine Compounds, 2nd ed. P. 450ff, Ellis Horwood PTR Prentice Hall, N.Y., 1992) dislcose 2+2 cycloaddition reactions between dienes and fluorinated ethylene, but only for conjugated dienes. Hudlicky also discloses the onset of cyclodimerization of reactants at temperature above 200° C.
[0005] Holler et al., (U.S. Pat. No. 3,481,914) discloses the polymerization of halogen-bearing olefins having a double bond in terminal position and having one of certain halogen-containing groups separated by at least two carbon atoms from said terminal vinyl group, the halogens being attached to primary, secondary, or aromatic carbons, but not to tertiary, allylic or benzylic carbons. Encompassed in the disclosure are terminal olefins having cyclobutyl rings with fluorine-containing substituents on the secondary carbons thereof. Polymerization is carried out by use of Ziegler-type coordination catalysts. Among the catalysts suitable are TiCl 3 in combination with Aluminum alkyl.
[0006] Coordination polymerization of olefins using metallocene catalysts is disclosed in Welborn et al., U.S. Pat. No. 5,324,800.
[0007] Brookhart et al., (WO 9623010A2) discloses a copolymer formed from ethene and a compound represented by the formula H 2 C═CH (CH 2 ) a R f R, particularly 1,1,2,2-tetrafluoro-2-[(1,1,2,2,3,3,4,4-octafluoro-9-decenyl)oxy] ethanesulfonyl fluoride, via a catalyzed reaction employing diimine-transition metal complexes. The polymer so-formed comprises a polyethylene backbone having randomly distributed pendant groups of 1,1,2,2-tetrafluoro-2-[(1,1,2,2,3,3,4,4-octafluoro-(mostly)octoxy] ethanesulfonyl fluoride, as well as alkyl branches. Brookhart's teachings are limited to comonomers having only secondary carbon atoms linking the fluorine-containing group and the olefinic double bond.
[0008] It has long been known in the art to form ionically conducting membranes and gels from organic polymers containing ionic pendant groups. Such polymers are known as ionomers. Particularly well-known ionomer membranes in widespread commercial use are Nafion® Membranes available from E. I. du Pont de Nemours and Company. Nafion® is formed by copolymerizing tetra-fluoro ethylene (TFE) with perfluoro(3,6-dioxa-4-methyl-7-octenesulfonyl fluoride), as disclosed in U.S. Pat. No. 3,282,875. Also known are copolymers of TFE with perfluoro (3-oxa-4-pentene sulfonyl fluoride), as disclosed in U.S. Pat. No. 4,358,545. The copolymers so formed are converted to the ionomeric form by hydrolysis, typically by exposure to an appropriate aqueous base, as disclosed in U.S. Pat. No. 3,282,875. Lithium, sodium and potassium are all well known in the art as suitable cations for the above cited ionomers.
[0009] Doyle et al., (WO 98/20573) disclose a highly fluorinated lithium ion exchange polymer electrolyte membrane (FLIEPEM) exhibiting a conductivity of at least 0.1 mS/cm comprising a highly fluorinated lithium ion exchange polymer membrane (FLIEPM), the polymer having pendant fluoroalkoxy lithium sulfonate groups, and wherein the polymer is either completely or partially cation exchanged; and, at least one aprotic solvent imbibed in said membrane. Electrodes and lithium cells are also disclosed.
[0010] In the polymers above-cited, the fluorine atoms provide more than one benefit. The fluorine groups on the carbons proximate to the sulfonyl group in the pendant side chain provide the electronegativity to render the cation sufficiently labile so as to provide high ionic conductivity. Replacement of those fluorine atoms with hydrogen results in a considerable reduction in ionic mobility and consequent loss of conductivity.
[0011] The remainder of the fluorine atoms, such as those in the polymer backbone, afford the chemical and thermal stability to the polymer normally associated with fluorinated polymers. This has proven to be of considerable value in such applications as the well-known “chlor-alkali” process. However, highly fluorinated polymers also have disadvantages where there is less need for high chemical and thermal stability. The fluorinated monomers are more expensive than their olefin counterparts, require higher processing temperatures, and often require expensive corrosion resistant processing equipment. Furthermore, it is difficult to form solutions and dispersions of fluoropolymers. Additionally, it is difficult to form strong adhesive bonds with fluoropolymers. In materials employed in electrochemical cells, for example, it may be advantageous to have better processibility at some cost to chemical and thermal stability. Thus, there is an incentive to develop ionomers with highly labile cations having reduced fluorine content.
[0012] Numerous publications disclose polyethers with either proximal ionic species in the polymer or in combination with ionic salts. Conductivities are in the range of 10 −5 S/cm and less. Le Nest et al., Polymer Communications 28, 303 (1987) disclose a composition of polyether glycol oligomers joined by phosphate or thiophosphate moieties hydrolyzed to the related lithium ionomer. In combination with propylene carbonate, conductivity in the range of 1−×10 −3 S/cm was realized. A review of the related art is found in Fauteux et al., Electrochimica Acta 40, 2185 (1995).
[0013] Benrabah et al., Electrochimica Acta, 40, 2259 (1995) disclose polyethers crosslinked by lithium oxytetrafluorosulfonates and derivatives. No aprotic solvents are incorporated. With the addition of lithium salts conductivity of <10 −4 S/cm was achieved.
[0014] Armand et al., U.S. Pat. No, 5,627,292 disclose copolymers formed from vinyl fluoroethoxy sulfonyl fluorides or cyclic ethers having fluoroethoxy sulfonyl fluoride groups with polyethylene oxide, acrylonitrile, pyridine and other monomers. Lithium sulfonate ionomers are formed. No aprotic solvents are incorporated. Conductivity was <10 −4 S/cm.
[0015] Narang et al., U.S. Pat. No. 5,633,098 disclose polyacrylate copolymers having a functionalized polyolefin backbone and pendant groups containing tetrafluoroethoxy lithium sulfonate groups. The comonomers containing the sulfonate groups are present in molar ratios of 50-100%. Compositions are disclosed comprising the polymer and a solvent mixture consisting of propylene carbonate, ethylene carbonate, and dimethoxyethane ethyl ether. Ionic conductivity of those compositions was in the range of 10 −4 −10 −3 S/cm.
SUMMARY OF THE INVENTION
[0016] The present invention provides for a substantially non-fluorinated polyolefin polymer comprising pendant groups comprising the radical of the formula
[0017] wherein R is oxygen or an alkylene or alkylene ether group wherein one or more of the hydrogens may be substituted by halogen, and R f is a radical of the formula
[0018] wherein R f ′ is a bond or is a fluoroalkylene or fluoroalkylene ether group, Y is F or O, Z is hydrogen or a univalent metal and m=0 or 1 with the proviso that m=0 when Y is F, and m=1 when Y is O, R f being ionizable, in character, when m=1.
[0019] The present invention further provides for a terminally unsaturated olefin of the formula
[0020] wherein R is oxygen or an alkylene or alkylene ether group wherein one or more of the hydrogens may be substituted by halogen, and R f is a radical of the formula
[0021] wherein R f ′ is a bond or is a fluoroalkylene or fluoroalkylene ether group, Y is F or O, Z is a univalent metal and m=0 or 1 with the proviso that m=0 when Y is F, and m=1 when Y is O, R f being ionizable in character when m=1.
[0022] Further provided is a process for producing a terminally unsaturated olefin, the process comprising combining in a vessel a diene of the formula
CH 2 ═CH—R—CH═CH 2 (IV)
[0023] wherein R is oxygen or an alkylene or alkylene ether group wherein one or more of the hydrogens may be substituted by halogen with up to 50 mol-% of a terminally unsaturated fluoroolefin having the formula
[0024] wherein R f ′ is a bond or is a fluoroalkylene or fluoroalkylene ether group, Y is F or O, Z is a univalent metal and m=0 or 1 with the proviso that m=0 when Y is F, and m=1 when Y is O. R f being ionizable in character when m=1;
[0025] heating to a temperature in the range of 180-600° C. for a period of about one second to about 24 hours. The process is preferably followed by cooling and removal of product.
[0026] Further provided is a polymerization process the process comprising the copolymerization of an olefin with the terminally unsaturated olefin (III), in the presence of an organometallic coordination catalyst, under polymerization conditions.
[0027] Further provided is an ionically conductive composition comprising the polymer having pendant groups (I) wherein, in (II), m=1 and Z is an alkali metal, and a liquid imbibed therewithin.
[0028] Further provided is a conductive composition comprising a liquid and the compound described by the formula (III) wherein, in (II), m=1 and Z is an alkali metal.
[0029] Further provided is an electrochemical cell comprising a cathode, an anode and a separator, at least one of which comprises the polymer having pendant groups (I) wherein, in (II), m=1 and Z is an alkali metal.
[0030] Further provided is an electrochemical cell comprising an anode, a cathode, a separator, and a conductive composition comprising the compound described by the formula (III) wherein, in (II), m=1 and Z is an alkali metal, and a liquid.
[0031] Further provided is an electrode comprising an electroactive material and the polymer having pendent groups (I) wherein, in (II), m=1 and Z is an alkali metal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] [0032]FIG. 1 depicts the metallocene coordination catalyst rac-ethylenebis-(indenyl)zirconium(IV) dichloride.
[0033] [0033]FIG. 2 depicts a nickel diimine catalyst.
DETAILED DESCRIPTION
[0034] The present invention is directed to a novel monomer, the method for its synthesis, and the polymer produced therefrom. The monomer of the invention is described by the formula
[0035] wherein R is an oxygen, alkylene or alkylene ether radical. Preferably R is an alkylene radical comprising from 2 to about 10 carbon atoms, preferably 2 to 6 carbon atoms, optionally substituted by one or more ether oxygens, and one or more of the hydrogens may be substituted by halogen. Most preferably, R is an ethenyl or butenyl radical. R f is a radical of the formula
[0036] wherein R f ′ is a bond or is a fluoroalkylene or fluoroalkylene ether group, Y is F or O, Z is a univalent metal and m=0 or 1 with the proviso that m=0 when Y is F, and m=1 when Y is O, R f being ionizable in character when m=1.
[0037] In a preferred embodiment, R f , is the radical represented by the formula
FSO 2 —CF 2 CF 2 —O—[(CFR f ″) x —O] y —
[0038] where R f ″ is perfluoroalkyl or fluorine, x=0, 1, 2, 3, or 4, y=0, 1, 2, or 3, with the proviso that when x=0, y=0. Most preferably, R f ″ is fluorine or trifluoromethyl, x=2, y=0 or 1. When x>1, the R f ″ groups need not be the same.
[0039] In a second preferred embodiment, R f is the radical represented by the formula
M+SO 3 −—CF 2 CF 2 —O—[(CFR f ″) x —O] y —
[0040] where R f ″ is perfluoroalkyl or fluorine, x=0, 1, 2, 3, or 4, y=0, 1, 2, or 3, with the proviso that when x=0, y=0 and M + is a univalent metal cation. Most preferably, R f ″ is fluorine or trifluoromethyl, x=2, y=0 or 1 and M + is Li + . When x>1, the R f ″ groups need not be the same.
[0041] The monomer of the present invention is formed by the 2+2 cycloaddition of an unconjugated diene having two terminally unsaturated carbons to a terminally unsaturated substituted fluoroolefin, as taught in general terms by Sharkey, Fluorine Chemistry Reviews , 2, P. P. Tarant, Ed., Marcel Dekker, 1968, New York.
[0042] Suitable for the practice of the invention are dienes represented by the formula
CH 2 ═CH—R—CH═CH 2 (IV)
[0043] wherein R is an oxygen, alkylene or alkylene ether group. Preferably, the alkylene group comprises from 2 to about 10 carbon atoms, most preferably 4 to 6 carbon atoms, optionally substituted by one or more ether oxygens, and one or more of the hydrogens may be substituted by halogen. Most preferably, R is an ethenyl or butenyl radical. While it is possible in the practice of the invention to obtain satisfactory results by substituting one or more halogens for one or more hydrogens in R, halogen substitution is not preferred.
[0044] Suitable terminally unsaturated fluoroolefins are represented by the formula
[0045] wherein R f ′ is a bond or is a fluoroalkylene or fluoroalkylene ether group, Y is F or O, Z is a univalent metal and m=0 or 1 with the proviso that m=0 when Y is F, and m=1 when Y is O, R f being ionizable in character when m=1.
[0046] In a preferred embodiment, the terminally unsaturated fluoroolefin is represented by the formula
SO 2 F—CF 2 —R f ′—CF 2 O—CF═CF 2
[0047] wherein R f ′ is a bond or is a fluoroalkylene group of from 1 to about 10 carbon atoms, optionally substituted by one or more ether oxygens and one or more hydrogen atoms; more preferably the terminally unsaturated fluoroolefin is represented by the formula
FSO 2 —CF 2 CF 2 —O—[(CFR f ″) x —O] y —CF═CF 2
[0048] where R f ″ is perfluoroalkenyl or fluorine, x=0, 1, 2, 3, or 4, y=0, 1, 2, or 3 with the proviso that when x=0, y=0. Most preferably, R f ″ is fluorine or trifluoromethyl, x=2, y=0 or 1.
[0049] The dienes suitable for the practice of the invention are well-known in the art and many are widely available commercially.
[0050] The terminally unsaturated fluoroolefins suitable for the practice of the invention, as represented by (V), encompass a wide range of compositions. Various of these compositions are described in U.S. Pat. Nos. 3,282,875, 4,358,545, and 5,463,005.
[0051] In one embodiment of the 2+2 cycloaddition process of the inyention, the diene and terminally unsaturated olefin are combined in a sealed, preferably corrosion resistant, pressure vessel, the olefin being present at a level of less than 50 mol-%, preferably less than 20 mol-%, heated under pressure to a temperature in the range of 180-250° C., preferably 190-210° C., and held for 4-12 hours, preferably 5-7 hours, followed by cooling. Preferably, the reaction mixture is subject to agitation. Suitable pressures range from autogenous pressure to as much as 2,000 atmospheres.
[0052] In a second embodiment of the 2+2 cycloaddition process of the invention, the diene and terminally unsaturated olefin may be reacted according the method of Sharkey, op. cit., wherein the reactants are fed continuously as gases to a tube heated to temperatures as high as 600° C. and therein being reacted, the reaction product being continuously removed.
[0053] It is a particularly surprising aspect of the present invention that under the preferred conditions of reaction, the 2+2 cycloadduct is made to high yield and purity, with little or no sign of either cyclodimerization of the olefin nor thermal degradation of the fluoroethersulfonyl- containing pendant group. The art teaches the formation of the cycloadduct of TFE with unconjugated dienes, and the cycloadduct of perfluoro(3,6-dioxa-4-methyl-7-octenesulfonyl fluoride) with conjugated dienes. It is known in the art that longer chain fluorinated alkenes are less reactive than TFE, and in particular, perfluoro(3,6-dioxa-4-methyl-7-octene-sulfonyl fluoride) is considerably less reactive than TFE. On the other hand, it is known that unconjugated dienes are less reactive than conjugated dienes.
[0054] Glazkov, op. cit., teaches the formation of the 2+2 cycloadduct of perfluoro(3,6-dioxa-4-methyl-7-octenesulfonyl fluoride) and conjugated dienes at temperatures of ca. 140° C. or possibly somewhat higher temperature. However, as hereinbelow demonstrated, no reaction is observed when an unconjugated diene is substituted for the conjugated diene of Glazkov.
[0055] One of skill in the art would know to increase the reaction temperature to achieve higher reactivity. But, in this case, Kartsov et al, Zhur. Organ. Khimii, 26 pp. 1573ff (1992), teach that perfluoropropyl vinyl ether, of which perfluoro-(3,6-dioxa-4-methyl-7-octenesulfonyl fluoride) is a derivative, undergoes isomerization and oligomerization in the temperature range from 160-205° C. Thus at temperature much above Glazkov's, and particularly in the range of 200° C., one of skill in the art might well be discouraged from attempting the 2+2 cycloaddition of perfluorosulfonyl vinyl ether-containing species and an unconjugated diene.
[0056] The successful achievement of the desired cycloaddition at temperatures in the vicinity of 200° C. is thus quite a surprising and beneficial result.
[0057] The 2+2 cycloadduct so formed is represented by the formula (III), as hereinabove described.
[0058] In the process of the invention, the monomer of the invention (III) is copolymerized with an olfenic comonomer, preferably ethylene, in the presence of a coordination catalyst. Suitable coordination catalysts include the Ziegler-Natta catalysts, preferably a Mg/Ti supported catalyst, metallocene catalysts, and diimine transition metal complexes as disclosed in Brookhart et al, op. ci.t., preferably alpha-diimine nickel and palladium catalysts Any of the methods of polymerization taught in the art hereinabove cited as suitable for olefins are suitable for the practice of the present invention. The presence of a metallocene complex is preferred.
[0059] In the preferred polymerization, the temperature at which the process is carried out is about −100° C. to about +200° C., preferably about 0° C. to about 150° C. Ethylene pressure ranges from atmospheric to about 275 MPa. Glassware and metal autoclaves have been found suitable for the practice of the invention. Further details relevant to the preferred polymerization process of the present invention may be obtained by extension from the teachings of Welborn et al., op. cit.
[0060] One of skill in the art will know that numerous coordination catalysts suitable for use in effecting polymerizations of olefins are available, and that different combinations of catalyst and reactants will be more or less effective at achieving high yields, or various degrees and types of branching in the final product.
[0061] While Barrick discloses a free-radical polymerization process suitable for the cycloadduct formed with butadiene and TFE, coordination polymerizaiton of the cycloadduct of butadiene and PSEPVE has not been accomplished, presumably because of the proximity of the electronegative fluorine containing groups to the olefinic double bond. For the same reason, the cycloadduct formed with pentadiene may polymerize with certain catalysts, but it is not considered to represent a practical monomer. However, the cycloadducts formed with hexadiene and larger homologs polymerize readily to good yield with a large number of catalysts.
[0062] In the most preferred embodiments of the present invention, the monomer of the invention is copolymerized with an olefin, preferably ethylene, and subsequently hydrolyzed if necessary, to form an ionic copolymer or an ionomer.
[0063] When the polymer formed by the coordination polymerization process of the invention is in the form of a sulfonyl fluoride, the polymer is preferably hydrolyzed by contacting with LiOH, as is known in the art; see for example Doyle (WO 98/20573) to form the lithium sulfate ionomer.
[0064] The ionomers of the present invention exhibit room temperature ionic conductivity of ca. 10 −7 -10 −6 S/cm when dry. However, it is found in the practice of the invention that numerous liquids when imbibed into the ionomer of the invention enhance the conductivity by orders of magnitude. Thus it has been found desirable in order to achieve the most useful embodiments of the present invention to form conductive compositions wherein liquids are imbibed into the ionomer of the invention.
[0065] The liquid employed will be dictated by the application. In general terms, it has been found in the practice of the invention that conductivity of the liquid-containing ionomer increases with increasing % weight uptake of the liquid, increasing dielectric constant of the liquid, and increasing Lewis basicity of the liquid, while conductivity has been observed to decrease with increasing viscosity and increasing molecular size of the liquid employed. The actual conductivity observed with any given combination of ionomer and liquid will depend upon the particular balance of properties. Thus, while in general a high dielectric constant is preferred, a highly basic solvent of low viscosity, small molecular size and low dielectric constant may provide superior conductivity in a given membrane than a larger, more viscous, less basic solvent having a higher dielectric constant. Of course, other considerations come into play as well. For example, excessive solubility of the ionomer in the liquid may be undesirable. Or, the liquid may be electrochemically unstable in the intended use.
[0066] One particularly preferred embodiment comprises the lithium ionomer combined with aprotic solvents, preferably organic carbonates, which are useful in lithium batteries.
[0067] In a preferred embodiment of the present invention, the comonomer concentration is preferably 1-10 mol-%, most preferably 2-7 mol-%.
[0068] While there is no limit to the shape or proportions of an article formed from the ionomers of the invention, thin films or membranes, preferably in combination with organic carbonates, are of particular utility for use as separators in lithium batteries, serving therein as single-ion conducting solid polymer electrolytes.
[0069] The ionomers of the invention are not fully thermoplastic and are not as readily processible by thermoplastic methods. It may be convenient to form membranes of the sulfonyl fluoride-containing polymer of the invention by using a screw extruder and a flat die. Alternatively, films can be melt pressed. The film so formed may then be converted to the desired ionic form by contacting it with LiOH to form the lithium sulfonate ionomer.
[0070] In an additional alternative, films may be cast from solutions or dispersions of the sulfonyl fluoride polymer or of the ionic polymers of the invention by casting onto a substrate and coagulating. No particular method is preferred over another, and the specific method will be chosen according to the needs of the particular practitioner.
[0071] In one particularly preferred embodiment of the invention, the ionomer of the invention is incorporated into an electrode suitable for use in lithium batteries. The preferred electrode of the invention comprises a mixture of one or more electrode active materials in particulate form, the ionomer of the invention, at least one electron conductive additive, and at least one organic carbonate. Examples of useful anode active materials include, but are not limited to, carbon (graphitic, coke-type, mesocarbons, polyacenes, and the like) and lithium-intercalated carbon, lithium metal nitrides such as Li 2.6 Co 0.4 N, tin oxide-based glasses, lithium metal, and lithium alloys, such as alloys of lithium with aluminum, tin, magnesium, silicon, manganese, iron, and zinc. Lithium intercalation anodes employing carbon are preferred. Useful cathode active materials include, but are not limited to, transition metal oxides and sulfides, lithiated transition metal oxides and sulfides, and organosulfur compounds. Examples of such are cobalt oxides, manganese oxides, molybdenum oxides, vanadium oxides, sulfides of titanium, molybdenum and niobium, lithiated oxides such as spinel lithium manganese oxides Li 1+x Mn 2−x O 4 , chromium-doped spinel lithium manganese oxides Li x Cr y Mn z O 4 , LiCoO 2 , LiNiO 2 , LiNi x Co 1−x O 2 where x is 0<×<1, with a preferred range of 0.5<×<0.95, LiCoVO 4 , and mixtures thereof. LiNi x Co 1−x O 2 is preferred. A highly preferred electron conductive aid is carbon black, preferably Super P carbon black, available from the MMM S. A. Carbon, Brussels, Belgium, in the concentration range of 1-10%. Preferably, the volume fraction of the lithium ionomer in the finished electrode is between 4 and 40%.
[0072] The electrode of the invention may conveniently be made by dissolution of all polymeric components into a common solvent and mixing together with the carbon black particles and electrode active particles. For cathodes the preferred electrode active material is LiNi x Co 1−x O 2 wherein 0<×<1, while for anodes the preferred electrode active material is graphitized mesocarbon microbeads. For example, a preferred lithium battery electrode of the invention can be fabricated by dissolving ionomer of the invention in a mixture of acetone and dimethyl-formamide, followed by addition of particles of electrode active material and carbon black, followed by deposition of a film on a substrate and drying. The resultant preferred electrode will comprise electrode active material, conductive carbon black, and ionomer of the invention, where, preferably, the weight ratio of ionomer to electrode active material is between 0.05 and 0.8 and the weight ratio of carbon black to electrode active material is between 0.01 and 0.2. Most preferably the weight ratio of ionomer to electrode active material is between 0.1 and 0.25 and the weight ratio of carbon black to electrode active material is between 0.02 and 0.1. This electrode can then be cast from solution onto a suitable support, such as a glass plate or current collector metal foil, and formed into a film using techniques well-known in the art. The electrode film thus produced can then be incorporated into a multi-layer electrochemical cell structure by lamination, as hereinbelow described.
[0073] It may be desirable to incorporate into the electrode composition of the invention such adjuvants as may be useful for such purposes as improving the binding of the components thereof, or providing improved structural integrity of an article fabricated therefrom. One particularly preferred additional material is SiO 2 which may be incorporated simply by dispersing the particles thereof into the same solution from which the electrode is being formed, as hereinabove described. Preferred are silica particles of an average particle dimension of less than 1.0 micrometers, the silica being present in the admixture at up to 50% by weight of the total.
[0074] In an alternative process, the dispersion of electrode-active material and optional carbon black and other adjuvants can first be cast onto a surface followed by addition of the ionomer of the invention in organic carbonate solution.
[0075] The invention is further described in the following specific embodiments.
EXAMPLES
Comparative Example 1
[0076] [0076] 12 . 5 g 1,5-hexadiene and 2.0 g of PSEPVE (CF 2 ═CFOCF 2 CF(CF 3 )OCF 2 CF 2 SO 2 F) prepared in the manner described in D. J. Connally and W. F. Gresham, U.S. Pat. No. 3,282,875 (1966), were combined in a sealed, heavy-walled glass tube and heated to 80° C. and held for 18 h, then heated to 120° C. and held for 6 h, and then heated to 155° C. and held for 6 h. GC analysis after each heating step showed only starting material was present. No reaction took place.
Example 1
[0077] [0077] 100 g 1,5-hexadiene, 50 g PSEPVE, and 1 g of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO, Aldrich Chemical Co.), were combined in a 400 cc Hastelloy C shaker tube heated to 200° C. and shaken for 6 hours. The contents were cooled and distilled to give recovered 1,5-hexadiene and a residue. The residue was then distilled in a Kugelrohr distillation appartus to afford 34.3 g of liquid, bp 50° C. at 0.0001 torr, (58% yield based on PSEPVE) whose infrared, GC-MS, 1 H and 19 F NMR spectra were consistent with a mixture of cis/trans isomers of the cycloaddition product.
Example 2
[0078] A mixture of 100 g 1,7-octadiene and 60 g PSEPVE was heated in a 400 cc Hastelloy C skaker tube at 200° C. for 6 hours. In a second tube, a duplicate mixture of 100 g 1,7-octadiene and 60 g PSEPVE was treated in the same way. The tubes were cooled, the contents from the tubes combined and distilled to give recovered 1,7-octadiene and 94.8 g of liquid, bp 95−100° C. at 0.25 torr, (63% yield based on PSEPVE) whose infrared, GC-MS, 1 H and 19 F NMR spectra were consistent with a mixture of cis/trans isomers of the desired cycloadduct.
Example 3
[0079] A Constructive Example
[0080] 10 g (18 mmol) of the cycloadduct of PSEPVE/1,7-octadiene of Example 2, 100 mL of anhydrous methanol, and 1.5 g lithium carbonate (20 mmol) is combined in a 250 mL flask and stirred under a blanket of nitrogen for 3 days at room temperature. The resulting slurry is filtered, and the filtrate is concentrated under vacuum and dried in a stream of warm (50° C.) nitrogen to afford 9.5 g (94% yield) of white solid, which is identified by its 1 H and 19 F NMR spectrum indicating the formation of the lithium sulfonate salt of the sulfonyl fluoride of Example 2.
Example 4
[0081] 3.2 mg (0.0077 mmol) of the catalyst rac-ethylenebis(indenyl)zirconium (IV) dichloride, depicted in FIG. 1, and the cycloadduct of PSEPVE/1,7-octadiene of Example 2 (5.0 g, 8.99 mmole) were mixed with 35 mL toluene in a Schlenk flask in a drybox. This was placed under 1 atm of ethylene and was purged with ethylene for 15 min at 0° C. Polymethylalumoxane (PMAO, 5.5 mL 12.9 wt % toluene solution) was added to the mixture. Upon stirring under 1 atm of ethylene at 0° C. for 60 min, 5 mL methanol was slowly added to the reaction mixture. The mixture was then poured into 150 mL methanol, followed by addition of 4 mL conc. HCl. After stirring at RT for 20 min, the white solid polymer was filtered, washed with methanol and dried in vacuo. Copolymer(6.98 g) was obtained. Based on 13 C NMR, the comonomer incorporation was 2.2 mole %. The copolymer exhibits a melting point of 106° C. by differential scanning calorimetry. Gel permeation chromatography (TCB, 135° C., Polyethylene standard): Mw=58,100; Mn=6,150; Mw/Mn=9.5.
Example 5
[0082] 3.2 mg (0.0077 mmol) of the catalyst rac-ethylenebis(indenyl)zirconium (IV) dichloride, depicted in FIG. 1, and the cycloadduct of PSEPVE/1,7-octadiene of Example 2 (12.0 g, 21.6 mmole) were mixed with 28 mL toluene in a Schlenk flask in a drybox. This was placed under 1 atm of ethylene and was purged with ethylene for 15 min at 0° C. PMAO (5.5 mL 12.9 wt % toluene solution) was added to the mixture. Upon stirring under 1 atm of ethylene at 0° C. for 15 min, 5 mL methanol was slowly added to the reaction mixture. The mixture was then poured into 150 mL methanol, followed by addition of 6 mL conc. HCl. Upon stirring at RT for 20 min, the white solid polymer was filtered, washed with methanol and dried in vacuo. Copolymer(8.93 g) was obtained. Based on 13 CNMR, the comonomer incorporation was 6.0 mole %.
Example 6
[0083] 12.2 mg (0.017 mmol) of the nickel catalyst depicted in FIG. 2 and the cycloadduct of PSEPVE/1,7-octadiene of Example 2 (8.0 g, 14.4 mmole) were mixed with 35 mL toluene in a Schlenk flask in a drybox. This was placed under 1 atm of ethylene and was purged with ethylene for 15 min at 0° C. PMAO (1.2 mL 12.9 wt % toluene solution) was added to the mixture. Upon stirring under 1 atm of ethylene at 0° C. for 45 min, 5 mL methanol was slowly added to the reaction mixture. The mixture was then poured into 150 mL methanol, followed by addition of 2 mL conc. HCl. Upon stirring at RT for 20 min, the white solid polymer was filtered, washed with methanol and dried in vacuo. Copolymer (0.274 g) was obtained. Based on 19 FNMR and 1 HNMR, the comonomer was incorporated. The copolymer exhibits a melting point of 98° C. by differential scanning calorimetry. Gel permeation chromatography (TCB, 135° C., Polyethylene standard): Mw=39,900; Mn=1,260; Mw/Mn=32.
Comparative Example 2
[0084] 3.2 mg (0.0077 mmol) of the catalyst rac-ethylenebis(indenyl)zirconium (IV) dichloride depicted in FIG. 1 and 2,2,3,3-tetrafluorocyclobutyl ethylene (6.5 g) were mixed with 35 mL toluene in a Schlenk flask in a drybox. This was placed under 1 atm of ethylene and was purged with ethylene for 15 min at 0° C. PMAO (5.5 mL 12.9 wt % toluene solution) was added to the mixture. Upon stirring under 1 atm of ethylene at 0° C. for 25 min, 5 mL methanol was slowly added to the reaction mixture. The mixture was then poured into 200 mL methanol, followed by addition of 5 mL conc. HCl. Upon stirring at RT for 20 min, the white solid polymer was filtered, washed with methanol and dried in vacuo. White polymer (2.687 g) was obtained. Based on 1 HNMR, it is ethylene homopolymer. No comonomer incorporation was observed. 19 FNMR was in agreement with 1 HNMR. The copolymer exhibits a melting point of 126° C. by differential scanning calorimetry.
Comparative Example 3
[0085] 12.2 mg (0.017 mmol) of the nickel catalyst depicted in FIG. 2 and 2,2,3,3-tetrafluorocyclobutyl ethylene (6.5 g) were mixed with 35 mL toluene in a Schlenk flask in a drybox. This was placed under 1 atm of ethylene and was purged with ethylene for 15 min at 0° C. PMAO (1.2 mL 12.9 wt % toluene solution) was added to the mixture. Upon stirring under 1 atm of ethylene at 0° C. for ca. 3 hr, 5 mL methanol was slowly added to the reaction mixture. The mixture was then poured into 200 mL methanol, followed by addition of 2 mL conc. HCl. Upon stirring at RT for 20 min, the white solid polymer was filtered, washed with methanol and dried in vacuo. White polymer (1.044 g) was obtained. Based on 1 HNMR, it is ethylene homopolymer. No comonomer incorporation was observed. 19 FNMR was in agreement with 1 HNMR. The copolymer exhibits a melting point of 98° C. by differential scanning calorimetry. Gel permeation chromatography (TCB, 135° C., Polyethylene standard): Mw=167,000; Mn=67,500; Mw/Mn=2.5.
Example 7
[0086] Melt-pressed films (3.75 cm×3.75 cm to 7.5 cm×7.5 cm) were obtained by placing approximately 0.25-1.0 g of the dried polymer of Example 4 between two sheets of Kapton® Polyimide Film (available from DuPont, Wilmington, Del.) and inserting between the platens of a hydraulic press (model P218C, Pasadena Hydraulic Industries, City of Industry, Calif.) equipped with Omron Electronics Inc. (Schaumburg, Ill.) E5CS temperature controllers. The polymer was preheated for two minutes at 140° C., then pressed at 2500 psi, followed by cooling under pressure.
[0087] The film was hydrolyzed and lithiated by treatment with filtered 1.0 M LiOH solution in 1:1 water/methanol. (The flask was heated in an oil bath where the temperature was monitored/controlled by thermocouple and a Yokogawa UT320 Digital Indicating Controller.) The film was placed in a 500 mL flask with 300 mL of the filtered LiOH solution. The reaction was heated to 80° C. for 6 hours, then allowed to cool to room temperature. The LiOH solution was replaced with a 1:1 water/methanol solution and the film was soaked overnight at room temperature. The solution was then replaced with fresh 1:1 water/methanol and heated to 80° C. for 4 hours. The film was dried in a VWR Model 1430 vacuum oven available from VWR Scientific, West Chester, Pa., at a vacuum of ca. 220 Torr and a temperature of 65° C. Further drying of the film under vacuum at elevated temperature (70-100° C.) was performed prior to conductivity testing.
Example 8
[0088] The polymer crumb of Example 5 was placed in a 500 mL flask with a stir bar and 350 mL of filtered 1.0 M LiOH in 1:1 water/methanol.
[0089] The reaction was heated at 65° C. for 6 hours, then cooled to room temperature. (The flask was heated in an oil bath where the temperature was monitored/controlled by thermocouple and a Yokogawa UT320 Digital Indicating Controller.) The polymer was collected by filtration and placed in a flask with 1:1 water/methanol and soaked at room temperature overnight. The polymer was again collected by filtration, placed in fresh 1:1 water/methanol, and heated to 65° C. for 4 hours with stirring. The rinsed polymer was then collected by filtration. Films were cast by dissolving 0.5 g of the polymer in hot 1:1 cyclohexanone/o-dichlorobenzene and pouring into a 50 mm diameter Teflon® PFA petri dish. The solvent was allowed to evaporate slowly to yield a film. Further drying of the film under vacuum at elevated temperature (70-100° C.) was performed prior to conductivity testing.
Examples 9-14
[0090] The hydrolyzed films were dried dried in a recirculating nitrogen oven (Electric Hotpack Company, Inc., Model 633, Philadelphia, Pa.) at 100° C. for 48 hours.
[0091] The dried hydrolyzed films were transferred to a sealed container from the vacuum oven while still warm and conveyed to a glove box having a positive pressure of dry nitrogen applied thereto, wherein the membrane was removed from the sealed container and allowed to come to room temperature. Still in the glove box, the membrane was then cut into several sections 1.0 cm by 1.5 cm in size. Typically, the specimens as prepared were then heated at 100° C. under vacuum for 24-48 hours.
[0092] A cooled 1.0 cm by 1.5 cm membrane sample was then soaked in an excess of one or more liquids in a sealed glass vial for 24 hours at room temperature. The liquids employed are all commercially available, and were used as received. Following immersion, the membrane sample was removed from the liquid bath, blotted with a paper towel to remove excess liquid, and tested.
[0093] Ionic conductivity was determined using the so-called four-point probe technique described in an article entitled “Proton Conductivity of Nafion® 117 As Measured by a Four-Electrode AC Impendance Method” by Y. Sone et al., J. Electrochem. Soc., 143,1254 (1996). The method as described applies to aqueous electrolyte membranes. The method was modified for purposes of obtaining the measurements reported herein for non-aqueous solvents by placing the apparatus described in a sealed glove box purged with dry nitrogen in order to minimize any exposure to water. The method was also modified by, substituting parallel linear probes traversing the full width of the test specimen for the point probes employed in the published method.
[0094] A 1.0 cm by 1.5 cm film was blotted dry and positioned into the conductivity cell. Cell impedance was determined over the range of 10 Hz to 100,000 Hz, and the value with zero phase angle in the higher frequency range (usually 500-5000 Hz) was ascribed to the bulk sample resistance in Ohms. The raw resistance value was then converted to conductivity, in S/cm, using the cell constant and liquid-swollen film thickness.
Example 9
[0095] A cooled 1.0 cm by 1.5 cm membrane sample of the hydrolyzed film of Example 7 dried in the manner hereinabove described was soaked in an excess of dimethylsulfoxide (ACS grade, 99.9+%, Alfa Aesar, Ward Hill, Md.) in a sealed glass vial for 24 hours at room temperature. The membrane was removed from the DMSO bath blotted with a paper towel to remove excess solvent, and tested using the four point probe test described above. Conductivity was greater than 10 −4 S/cm.
Example 10
[0096] A further 1.0 cm by 1.5 cm membrane sample prepared in the manner of Example 9, was treated according to the method therein described except that the solvent was a 1:1 by volume mixture of propylene carbonate (99%, Aldrich Chemical Co., Inc., Milwaukee, Wis.) and dimethoxyethane (98%, Aldrich Chemical Co., Inc., Milwaukee, Wis.). The conductivity was greater than 10 −5 S/cm.
Example 11
[0097] A 1.0 cm by 1.5 cm membrane sample prepared in the manner of Example 9 was treated according to the method therein described except that the solvent was gamma-butyrolactone (99%, Aldrich Chemical Co., Inc., Milwaukee, Wis.). The conductivity was greater than 10 −5 S/cm.
Example 12
[0098] A 1.0 cm by 1.5 cm membrane sample prepared in the manner of Example 9 was treated according to the method therein described except that the membrane sample was removed from the dry box environment and heated to 80° C. in deionized water on a hot plate (PMC 730 Series, Dataplate Digital Hot Plate). After allowing the membrane and water bath to cool, the membrane sample was removed, blotted with a paper towel, and tested using the four point probe test described above. The conductivity was greater than 10 −4 S/cm.
Example 13
[0099] A 1.0 cm by 1.5 cm membrane sample prepared in the manner of Example 12 was treated according to the method therein described except that following the heating in a deionized water bath, the membrane was immersed into an excess of 1.0 M nitric acid (Reagent grade, EM Science, Gibbstown, N.J.) and heated to T=80° C. for one hour. Following this procedure, the membrane was rinsed with deionized water for several hours. The membrane was clear and intact after this procedure. Following this, the membrane was characterized according to the procedures given above and the conductivity was greater than 10 −3 S/cm.
Example 14
[0100] A cooled 1.0 cm by 1.5 cm membrane sample of the hydrolyzed film of Example 8 dried in the manner hereinabove described was then soaked in an excess of a 1:1 by volume mixture of ethylene carbonate (98%, Aldrich Chemical Co., Inc., Milwaukee, Wis.) and dimethyl carbonate (99%, Alfa Aesar, Ward Hill, Md.) in a sealed glass vial for 2 hours at room temperature. The membrane was removed from the solvent bath, blotted with a paper towel to remove excess solvent, and tested using the four point probe test described above. Solvent uptake was 319%. Conductivity was greater than 10 −4 S/cm. | This invention concerns olefins having a terminally disposed fluorocyclobutyl ring bearing an ionic functionality or a precursor thereto, a process for the production thereof, and polymers formed therefrom. | 2 |
RELATED APPLICATIONS
This application claims priority from U.S. Provisional Application No. 61/811,218 filed on Apr. 12, 2013.
FIELD OF THE INVENTION
This invention relates to an Emergency Barricade System (EBS) to protect potential victims from harm-doers. It essentially comprises a Quickly Activated Bolt Latch (QABL) and an Unlocking Tool to unlock the locked bolt latch from the exterior of the barricaded area by rescuers. The QABL is a door bolt lock system that can be hastily locked by foot in a crisis and also can be unlocked by foot without a key or without having to search for the lock.
BACKGROUND OF THE INVENTION
Tragic situations such as the school shootings in Newtown, Conn. and Columbine, Colo. have taken place over the past few years in this country. Many young lives have been lost in these tragedies because the shooter had unfettered access to his victims. In such situations, many lives would have been saved if the victims had been able to quickly and easily barricade themselves in their class-rooms or other secure areas.
The EBS described below provides protection to potential victims who might find themselves in a dangerous situation and need to barricade themselves from persons who may desire to do them harm.
SUMMARY OF THE INVENTION
The embodiment of the Emergency Barricade System (EBS) described herein comprises a Quickly Activated Bolt Latch (QABL) and an Unlocking Tool (UT).
The QABL comprises a casing with a longitudinally oriented bore which is open at least at one end. The casing has a means for attaching to a door, with the open end of the bore generally aligned with the edge of the door. A sliding element (SE) is located within the casing. The SE closely fits within the bore of the casing and has a first end and a second end. The SE is capable of being slidingly positioned within the bore in a first (disengaged) position or in a second (engaged) position. In the engaged position, the first end of the SE protrudes through the open end of the bore to engage a matching bolt-hole in the floor or door frame. During normal times, the SE is held in the disengaged position by a spring means. At times of crisis, the SE can be rapidly moved from the disengaged position to the engaged position against the action of the spring means by downwards pressure from the user's foot. The SE is held in its engaged position by a locking means. When the crisis is over, the SE is released from its engaged position by an unlocking means. When the SE is released, the spring means returns the SE to the disengaged position.
In the embodiment of the Emergency Barricade System (EBS) described herein, the bore of the QABL has a second open end which protrudes out of the second open end when the SE is in the disengaged position. A foot pedal is attached to the second end of the SE to move it quickly from the disengaged position to the engaged position against the action of the spring means. The spring means to hold the SE of the QABL in the disengaged position is a partially compressed helical spring positioned around the sliding element between the second open end of the bore of the casing and the foot pedal. The spring is generally fully compressed when the foot pedal is pressed.
In the embodiment of the Emergency Barricade System (EBS) described herein, the locking means to lock the SE in place when it is in the engaged position comprises a toggle bar and a spring which is located in a longitudinal cavity in the SE. The toggle bar is pivotingly attached at its first (lower) end within the cavity. The spring maintains the second (free) end of the toggle bar in sliding contact with the inside surface of the bore. The bore has an engaging surface to hold the toggle bar in a swung out position to arrest the SE in an engaged position and prevent the spring means from returning the SE to the disengaged position.
Further in the embodiment of the Emergency Barricade System (EBS) described herein, the unlocking means to unlock the SE from the engaged position comprises a release pin which is located in a pin-hole in the casing of the QABL. The pin-hole is located over the free end of the toggle bar when the SE is in an engaged position. The release pin slidingly fits and partially protrudes out of the pin-hole in the casing. When the protruding end of the pin is pressed, the pin pushes the second end of the toggle bar past the engaging surface within the bore to release the SE from its engaged position. A spring means is provided to return the release pin to its partially protruding position within the pin-hole in the casing after it has been pressed to release the SE of the QABL from its engaged position. As an option, a toggle lever is provided in contact with the protruding end of the release pin to facilitate the pressing of the release pin.
The EBS described herein further comprises an Unlocking Tool (UT) means to unlock the QABL from outside the room. The UT means is configured as a flat bar having a crook at its insertion end to engage the unlocking means of the QABL. The flat bar is thin enough to be inserted in the gap between the closed door and the doorframe or floor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a plan-view representation of the Quickly Activated Bolt Latch (QABL) in a disengaged position.
FIG. 1B is a plan-view representation of the QABL in an engaged position.
FIG. 1C is an end-view representation of the QABL.
FIG. 2A is a cross-sectional view representation of the QABL in a disengaged position.
FIG. 2B is a cross-sectional view representation of the QABL in an engaged position.
FIG. 3 is a three-dimensional exploded view representation of part of the QABL showing the internal details of the locking mechanism.
FIG. 4 is a cross-sectional view representation of the QABL with a toggle-lever to facilitate the operation of the unlocking mechanism.
FIG. 5 is a representation of the Unlocking Tool (UT) for unlocking the QABL from outside the room.
DETAILED DESCRIPTION
The Emergency Barricade System (EBS) described herein comprises a Quickly Activated Bolt Latch (QABL) 100 and an Unlocking Tool 200 to unlock the bolt latch from the exterior of the barricaded area by rescuers. The QABL can be quickly and easily activated to safeguard persons who are in a potentially threatened position.
FIGS. 1A, 1B, 1C, 2A, 2B, and 3 represent an embodiment of the Quickly Activated Bolt Latch (QABL) 100 , which is disclosed herein.
QABL 100 comprises a casing 110 with a longitudinally oriented cylindrical bore 114 through which a sliding element shown as bolt 120 (described further below) is located. Further, casing 110 has a means, which is shown in FIG. 1A as base 112 with mounting holes 112 h , to attach the casing to a door. Base 112 can be attached to a door with screws through mounting holes 112 h . Ideally, casing 110 is attached to the lower edge of the door. In this position, bolt 120 engages a mating bolt-hole located in the floor or door-frame when the lower portion of bolt 120 is slid out of casing 110 (as described further below). This action secures the door firmly in a closed position
Bore 114 is generally cylindrical throughout its length except that it has an internal longitudinally oriented square or rectangular cross-sectioned slot 115 (see FIGS. 2A, 2B, and 3 ) in its lower section to accommodate a locking means for locking the bolt 120 in the engaged position with the bolt-hole. The locking means is shown as catch mechanism 124 (described below) on bolt 120 . Slot 115 also creates step 115 s within bore 114 which engages catch mechanism 124 as will be described below. Slot 115 is created by machining a square or rectangular channel of desired length longitudinally within the inside cylindrical surface of the lower section of bore 114 .
Further, an unlocking means 116 is provided on casing 114 . The unlocking means comprises a cylindrical pin-hole 116 h in casing 110 and release pin 116 p . Cylindrical pin-hole 116 h is provided at a generally perpendicular orientation to slot 115 of casing 110 . Pin-hole 116 h is designed to contain release pin 116 s , which will be described below.
Bolt 120 is a cylindrical member about 0.75 inch in diameter and about 7 inches long which slidingly fits within bore 114 . Groove 120 g (see FIGS. 2A and 2B ) is provided in the lower section of bolt 120 to house catch mechanism 124 . Catch mechanism 124 comprises a toggle-bar 124 r which is pivotingly attached at its first end 124 r 1 within groove 120 g by pin 124 p . Spring 124 s is provided to bias second end 124 r 2 of toggle-bar 124 r outwards from groove 120 g . Thus toggle-bar 124 r pivots around pin 124 p and normally is biased such that its second (free) end 124 r 2 swings out of groove 120 g until it is mechanically forced back into groove 120 g.
A foot pedal 125 is attached to the upper end 120 u of bolt 120 . To keep bolt 120 in a normally disengaged position, helical spring 122 is provided around bolt 120 between foot pedal 125 and casing 110 . In the uncompressed position, spring 122 pushes bolt 120 upwards to its normally disengaged position as shown in FIGS. 1A and 2A . When foot pedal 125 is pressed down, bolt 120 is pushed down further into bore 114 such that its lower end 120 a extends out of casing 110 to engage the bolt-hole as shown in FIG. 2B .
To operate QABL 100 , the door is closed so that bolt 120 is located over the bolt-hole. Bolt 120 of QABL 100 is now in the disengaged position shown in FIGS. 1A and 2A . The user then presses foot pedal 125 using his/her foot to move foot pedal 125 and attached bolt 120 towards the bolt-hole against the reactive force of spring 122 which is now compressed as shown in FIGS. 1B and 2B . The relative lengths and positions of slots 115 and toggle-bar 124 r are designed such that when lower end 120 a of bolt 120 is sufficiently inserted (e.g. 2.5 inches) into the bolt-hole, toggle-bar 124 r is automatically released from its confined position (shown in FIGS. 1A and 2A ) within the upper cylindrical section of bore 114 . In this unconfined position (shown in FIGS. 1B and 2B ), the free end 124 r 2 of toggle-bar 124 r automatically swings out into slot 115 of bore 114 due to the action of spring 124 s . When the user takes his/her foot off foot pedal 125 , the reactive force of spring 122 pushes foot pedal 125 and attached bolt 120 upwards. Since toggle-bar 124 r now is in a swung out position within slot 115 of bore 114 , it engages step 115 s (shown in FIGS. 1B and 2B ) of slot 115 as it moves upwards within bore 114 . Bolt 120 is thus constrained in a locked position with its lower section 120 m embedded in the bolt-hole. The door is now secured against potential intruders. As a secondary action, when free end 124 r 2 of toggle-bar 124 r is swung out of groove 120 g by spring 124 s into slot 115 of bore 114 , free end 124 r 2 of toggle-bar 124 r also pushes out release pin 116 p through pin-hole 116 h to a partially protruded position.
When bolt 120 is to be unlocked from the bolt-hole, the user presses release pin 116 p with his/her finger or foot. When release pin 116 p is pressed, it pushes free end 124 r 2 of toggle-bar 124 r away from step 115 s of slot 115 in bore 114 back into groove 120 g of bolt 120 . The reactive force of spring 122 pushes foot pedal 125 and attached bolt 120 upwards. Lower section 120 m of bolt 120 is thus dis-embedded from the bolt-hole and the door can be opened. Spring 116 s may be provided to maintain release pin 116 p normally in a protruded state.
Release pin 116 p can be pressed manually by the user from within the barricaded area to unlock QABL 100 or can be pressed from outside the room using the Unlocking Tool (described below). Since release pin 116 p has a rather small contact area, a release lever 119 can be provided as an option (shown in FIG. 4 ). Release lever 119 has a free end 119 f which is in contact with protruding end 116 pe of release pin 116 p . The second end 119 p of release lever 119 is pivotingly attached to casing 110 . Thus release lever 119 provides a much larger contact area to facilitate unlocking QABL 100 from outside as described in the above paragraph. When free end 119 f of release lever 119 is pressed, it presses release pin 116 p to unlock bolt 120 from its locked position as described above.
QABL 100 can also be unlocked by a rescuer from outside the barricaded area by using an Unlocking Tool which is designed specifically for this purpose. FIG. 5 shows a representation of Unlocking Tool 200 that can be used for this purpose. The tool is configured as a flat, rigid bar 200 with a handle 200 h at its first end and a crook 200 c at its second end. The thickness of bar 200 is designed such that it can be inserted through the gap between the door and the floor or door frame.
The user holds the bar by handle 200 h and then manipulates it until end 200 ce of crook 200 c is positioned and contacts protruding end 116 pe of release pin 116 p or release lever 119 on QABL 100 . The user then pulls on handle 200 h to press release pin 116 p or release lever 119 to release bolt 120 from its locked position (described above) to open the door.
Thus QABL 100 does not need a key for it to be opened from the outside. Installation is simple as it does not require a key-hole to be drilled in the door for its operation. It can be quickly and easily installed in any door, preferably at the bottom of the door panel so that it can be quickly and easily activated by the user simply by pressing down on the foot pedal. The EBS can be operated using gross motor skills only.
Thus, in a potentially threatening class-room situation, a teacher can activate the bolt without taking his/her eyes off the students or off the threatening situation. Further, unlocking means 116 is simple enough that even a very young student can operate it to open the door. The QABL is ruggedly built so that it will be difficult for an intruder to physically kick in the door. Also, it will still function if the intruder fires his gun at it. The EBS can be used not only in class-rooms but in every situation where quick action is required for the potential victim to barricade himself or herself. Such situations would include airplane cockpits, offices, safe-rooms, etc.
The preferred embodiment of the EBS has been generally described above in a conceptual manner without detailed dimensions and other engineering data. It will be obvious that persons having ordinary skill in the art can select the design parameters to design the QABL and the Unlocking Tool of the EBS described herein for use in specific situations.
While preferred 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 will occur to those skilled in the art without departing from the invention herein. Accordingly, it is intended that the invention be limited only by the spirit and scope of the following claims. | An Emergency Barricade System (EBS) to protect children in school shootings from harm-doers is disclosed. The EBS comprises a Quickly Activated Bolt Latch (QABL) and an Unlocking Tool (UT). The QABL is attached to the inside surface of a classroom door. In an emergency, the bolt of the QABL can be quickly slid into a bolt-hole by foot pressure. The bolt is held in place in the bolt-hole by a locking means in the QABL. The bolt can be easily unlocked by pressing on a release pin on the QABL. A spring is provided in the QABL to automatically return the bolt to its normal position. An Unlocking Tool is provided to enable rescuers to unlock the QABL from outside the classroom. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of co-pending U.S. application Ser. No. 10/546,821, which was filed as International Application No. PCT/NO2004/00054 on Feb. 26, 2004, and for which priority is claimed under 35 U.S.C. § 120. This application also claims priority to Application No. 2003 0968, which was filed in Norway on Feb. 28, 2003, under 35 U.S.C. § 119. The entirety of each of the above-identified applications is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention regards a rotation unit for a torque tong.
[0004] 2. Description of Background Art
[0005] A prior art torque tong is described in NO 163973, which concerns a torque tong arranged both to break and make a threaded connection between two pipes, and also spin one of the pipes relative to the other in order to uncouple the pipes from each other or tighten the connection.
[0006] In older solutions, a special device was used to make and break the connection, while another special device was used to spin the pipes apart or together. The solution of NO 163973 allowed both making/breaking and spinning to be carried out in the same apparatus.
[0007] The solution of NO 163973 also entailed the advantage of being able to handle pipes within a wide range of diameters.
[0008] In order to achieve this, NO 163973 proposes the use of one or more master cylinders which upon rotation of the rotary part of the tong, and as a result of the placement of the cylinders, are pressed together, applying pressure to a number of slave cylinders. The slave cylinders will in turn displace jaws to engage one of the pipes involved, ensuring that these maintain a sufficiently powerful grip on the pipe to break or make the connection to a prescribed torque without the jaws slipping relative to the pipe.
[0009] A solution similar to that of NO 163973 has been described in NO 306572. Here the jaws are also equipped with respective slave cylinders. These are pressurized by a master cylinder mounted on the rotary part, which master cylinder is then influenced by a piston mounted outside the rotary part. The jaws are brought into engagement with the pipe by increasing the pressure from the master cylinder Valves ensure that the pressure in the slave cylinders is maintained independently of the master cylinder.
[0010] In a subsequent patent application (WO 00/45027) from the same applicant as NO 306572, it is stated that in the solution of the latter patent, the piston must push the master cylinder repeatedly in order to provide a sufficient volume of hydraulic fluid to push the jaws into engagement and also achieve sufficient retaining power. This causes a significant delay in the operation. In WO 00/45027, this problem is apparently solved by means of pressure accumulators.
[0011] Rotation of the rotary part is largely achieved by use of cogwheels directly engaged with toothing on the rotary part.
SUMMARY OF THE INVENTION
[0012] The present invention provides a drive system for rotating the rotary part of the tong. This system has advantages over the existing systems, which are mainly based on geared drive through several gear wheels placed along the periphery of the rotary part.
[0013] These advantages are achieved by a rotational unit for a torque tong, comprising a fixed part; and a rotary part designed to grip a pipe to be rotated, said rotary part comprising at least one movable gripping jaw arranged to be moved into engagement with the pipe; toothing arranged to engage at least one chain, the toothing including teeth, said at least one chain being operatively connected to an actuator in order to move the at least one chain and so impart rotary movement to the rotary part; and an opening at a periphery thereof for introduction of a pipe, wherein the at least one chain extends across a section larger than the opening, thus ensuring that the at least one chain and the toothing on the rotary part are engaged at all times, the opening is arranged to be kept open during the rotation of the rotary part, and a rectilinear distance over which the at least one chain extends between the teeth of the toothing located closest to and on either side of the opening is equivalent to a whole number of teeth.
[0014] The rotary part has an opening at the periphery for introduction of a pipe, and the chain extends across a sector of a circle larger than the opening, thus ensuring that the chain and the toothing on the rotary part are engaged at all times.
[0015] The rotary part is directly engaged with at least two chains that act synchronously, thus reducing the strain on the chain.
[0016] The chains are arranged on diametrically opposite sides of the rotary part, thus giving a symmetric loading on the rotary part.
[0017] The rotary part has replaceable teeth, thus simplifying maintenance.
[0018] The chain extends over a first cogwheel operatively connected to a motor, e.g. a hydraulic motor, and a second cogwheel that acts as a turning wheel, the cogwheels being spaced apart at the periphery of the rotary part; this provides a compact solution with few components.
[0019] A distance over which the chain extends between the teeth located nearest the opening, on either side of this, is equivalent to a whole number (integer) of teeth, thus ensuring that the chain lands on a tooth on the opposite side of the opening upon passing over this.
[0020] The rotary part is equipped with an uneven number of teeth, making it easier to ensure that the distance over which the chain extends between the two teeth nearest the opening, is equivalent to a whole number of teeth.
[0021] By making the number of teeth 21 , a practical solution is obtained, whereby the chain will always land on a tooth when passing the opening.
[0022] The rotary part is slidingly supported on a plate on the fixed part, thus achieving cost effective and secure support of the rotary part.
[0023] A chain drive ensures a more robust design and smoother running. Smoother running reduces the risk of “bite marks” from the jaws on the pipe. The chain will engage the rotary part across a significantly longer area than a cogwheel. This will reduce the loading on each tooth on the rotary part, and compared with direct engagement between a cogwheel and the rotary part, the loading on the chain will be more even. Moreover, the chain will be able to engage the rotary part over a section large enough to ensure that even if the rotary part does not have teeth around its entire periphery (e.g. due to an opening for introduction of pipes), the chain will be in engagement with the rotary part at all times. This would not be the case in the event of a direct engagement with cogwheels, where the cogwheels would engage and disengage the rotary part at every rotation. This increases the strain and the risk of damage to both cogwheels and teeth on the rotary part.
[0024] In the case of direct engagement with a cogwheel, the component most exposed to wear will be precisely the cogwheel. In the case of chain drive, it will be the chain. It is easier to replace a worn or damaged chain than a cogwheel, as a cogwheel inevitably of necessity would have to be securely fixed to the shaft, while the chain is arranged more or less loosely around the cogwheels. In addition, the teeth on the rotary part may be arranged so as to be replaceable, allowing easy replacement of worn or damaged teeth. The tong will be usable even with missing teeth, as the chain will be in engagement with other teeth. Drive systems incorporating a chain will not be as sensitive to dirt as drive systems based on e.g. direct gearing. The noise generated by the system will also be less.
[0025] Furthermore, the costs of producing such a system could also be lower.
[0026] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
[0028] FIG. 1 shows a rotary torque tong according to the present invention;
[0029] FIG. 2 shows the rotation unit of the torque tong according to the invention;
[0030] FIG. 3 mainly shows the rotary part of the rotation unit;
[0031] FIG. 4 is a sectional view of the rotation unit;
[0032] FIG. 5 shows a hydraulic connection diagram of the most important components that bring about the gripping of the pipe;
[0033] FIG. 6 shows an alternative hydraulic connection;
[0034] FIG. 7 shows alternative gripping and holding means, with FIG. 7 a showing a jaw fully retracted from the pipe;
[0035] FIG. 7 b showing the jaw about to be pushed into engagement with the pipe; and
[0036] FIG. 7 c showing the jaw fully engaged with the pipe; and
[0037] FIG. 8 illustrates a principle for distribution of teeth on the rotary part.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] FIG. 1 shows the rotary torque tong according to the present invention. The tong has a frame 60 generally consisting of a horizontal part 61 and a vertical part 62 . The frame 60 may be mounted on a guide rail (not shown) to allow it to be displaced horizontally on a drill floor for the tong to engage or disengage a pipe 70 (shown in FIG. 4 ).
[0039] On the vertical part 62 of the frame 60 there is disposed, as the lowermost component, a holding unit (back-up) 63 . This comprises gripping jaws 64 arranged to grip a pipe below a pipe joint (not shown) in order to hold this. The construction of the holding unit is, in principle, conventional and will be understood by a person skilled in the art. Thus this will not be explained in any detail herein.
[0040] Above the holding unit 63 there is a rotation unit 65 arranged to grip a pipe above a pipe joint. The rotation unit 65 will be explained in detail in the following. Above the rotation unit 65 there is disposed a spin unit 66 . This unit is arranged to spin the pipe above the pipe joint out of threaded engagement with a pipe below the pipe joint, or spin the pipe into threaded engagement with the pipe below the pipe joint. The spin unit has a lighter construction than the rotation unit 65 and operates at a significantly lower torque than the rotation unit. Thus it is not capable of breaking or making a pipe joint. The spin unit 65 may however rotate pipes at a considerably higher speed than the rotation unit 65 .
[0041] FIG. 2 shows the rotation unit 65 of the tong according to the invention. It comprises a rotary part 40 and a fixed part 41 . The rotary part 40 is mounted on a plate 42 attached to the fixed part via bolts 54 and brackets 55 . The plate 42 has an opening 49 . The rotary part is generally disk-shaped with a central cavity 44 and an opening 45 extending from the cavity 44 to the periphery of the disk 40 . Toothing 43 is provided around the periphery of the rotary part 40 . This toothing may consist of single teeth fixed, e.g. screwed, to the disk 40 . The toothing 43 engages two chains 46 , 47 , each of which extends across two cogwheels 48 , 50 . One of the cogwheels 50 is power-coupled to a motor 51 , preferably a hydraulic motor. Alternatively, one chain may be used, which extends across a sector of a circle greater than either of the chains 46 , 47 . When one chain 46 , 47 passes over the opening 45 , it is important for the chain to land on the first tooth after the opening as accurately as possible, to avoid wear on the tooth and chain to the greatest possible extent, and to avoid jerky movements. Consequently, the distance over which the chain extends between the teeth on either side of the opening 45 is matched so as to be equivalent to a whole number of teeth. It has been found that this may be achieved by satisfying the following two equations:
[0000]
t
2
·
1
sin
(
2
·
π
-
α
2
·
N
2
)
=
0
(
1
)
2
·
a
sin
(
N
1
·
t
2
·
r
)
-
α
=
0
(
2
)
[0000] in which:
t is the chain pitch, in mm,
N 1 is the number of teeth that will fit over the opening 45 , between the two teeth nearest the opening,
N 2 is the number of teeth along the curved section of the rotary part 40 ,
α is the angle (in radians) between the teeth nearest the opening, and
r is the radius of the rotary part 40 at the chain, i.e. the distance from the centre of the rotary part 40 to the centre of the chain rollers.
[0042] In FIG. 8 , the relationship defined above through equations (1) and (2) has been illustrated by an example of an embodiment. The figure shows a schematic plan view of the rotary part 40 . Also shown is one chain 46 extending across the two cogwheels 48 , 50 . A number of teeth 43 are shown around the periphery of the rotary part 40 . In the example shown, it has been decided that there should be room for 67 teeth along the curved section of the rotary part 40 . However, there is no requirement for such a high density of teeth, and so only every third tooth has been installed, except on either side of the opening 45 , where two teeth have been placed close to each other in order to provide greater strength at this location, and diametrically opposite of the opening, where three teeth in a row are missing, in order to achieve symmetry. Using a smaller number of teeth than the maximum possible allows a reduction in costs and makes it easier to mount the teeth.
[0043] The rectilinear distance L r between the two teeth 43 a and 43 b closest to the opening 45 on either side of this, is shorter than the curved distance L b , that follows the curve of the rotary part 40 . If the chain had followed the curved distance L b the positioning of the teeth would be given unequivocally by the total number of teeth and the radius r of the rotary part at the chain. The chain will however follow the rectilinear distance L r . Consequently, this distance L r must provide room for a whole number of teeth. In the example shown, it has been decided that there should be room for 8 teeth along the rectilinear distance L r between the two teeth 43 a and 43 b.
[0044] Also, the chain has been chosen to have a pitch, i.e. a distance t between the centres of each of the chain's 46 rollers, of 76.2 mm.
[0045] Inserting these figures into the equations (1) and (2) will make it possible to calculate the angle α and the radius r. This gives the radius as 911.7119 mm and the angle α as 0.68176 rad, which is equivalent to 39.06°. If the stretching of the chain 46 between the teeth 43 a and 43 b had not been taken into account, the chain would have missed the tooth by 12 mm. This would have resulted in a great strain on this tooth and jerky movements.
[0046] The above way of spacing the teeth on a rotary part, and the condition of equations (1) and (2), may also be used in other contexts than that which has been described, where for various reasons, one may wish to have access to an area inside the toothing of the rotary part.
[0047] The fixed part 41 comprises a frame 52 that supports the plate 42 , the cogwheels 48 , 50 and the motors 51 . The frame 52 is mounted so as to float in a joint 53 . Through this mounting, the rotation unit 65 can automatically orient itself relative to the pipe to be gripped.
[0048] The fixed part 41 has gripping cylinders 4 , 5 , 6 mounted on it. These use their piston rod to push against a protrusion 1 c , 2 c , 3 c on each of three gripping jaws 1 , 2 , 3 .
[0049] However, the piston rod is not attached to the protrusion. The holding cylinders 1 a , 2 a , 3 a are located inside the gripping jaws 1 , 2 , 3 and so are not visible in FIG. 2 , but one of them may be seen in FIG. 4 . Three displaceable gripping jaws may be used, as shown, but it is also possible to use more or fewer gripping jaws. When using fewer gripping jaws, one or more fixed gripping jaws may also be used, which are rigidly mounted to the rotary part. This will depend on how much of the pipe dimension the tong is to be used on.
[0050] When the rotary part is to be rotated, the motors 51 are actuated, causing the chains 46 , 47 to move in the same direction. Thus the chains 46 , 47 rotate the rotary part 40 , which slides on slide bearings (not shown) on the plate 42 .
[0051] In FIG. 3 the fixed part of the rotation unit has been removed. Thus in this figure, two slave cylinders 18 and two master cylinders 19 become visible. Preferably, these are positioned so as to act against each other and synchronously, so that the master cylinder 19 does not contribute to the rotation of the rotary part 40 .
[0052] The rotation unit 65 is equipped with sensors (not shown) to detect the position of the rotary part 40 , to allow the rotary part to be carefully positioned with the opening 45 in line with the opening 49 , so that the tong may be pushed onto pipes to be screwed, by guiding the openings 45 , 49 onto the pipe. The jaws 1 and 3 closest to the opening 45 have been retracted to make room for the pipe to pass. Therefore these jaws 1 and 3 must be moved over a greater distance than jaw 2 before engaging the pipe.
[0053] Description will now be given of a relief mechanism for the holding cylinders. This comprises two plates 57 and 58 which, apart from an opening 45 a and 45 b , are annular. The lower plate 58 lies on the rotary part 40 and is operationally connected to three relief valves 10 b , 11 b , 12 b (see FIG. 5 ). The upper plate 57 is connected to the fixed part 41 via actuators 56 . The valves 10 b , 11 b , 12 , which relieve the pressure from the holding cylinders 1 a , 2 a , 3 a (see FIG. 5 ), are operated by actuating the actuators 56 . The upper plate 57 is forced down against the lower plate 58 , which in turn displaces the valves 10 b , 11 b , 12 b from a first position to a second position. The upper plate 57 will be able to force the lower plate down regardless of the position of the rotary part 40 relative to the fixed part 41 .
[0054] FIG. 4 is a sectional view of part of the rotation unit showing, among other things, one of the motors 51 , one of the chains 46 , the rotary part 40 , the plate 42 , one of the gripping cylinders 5 , which pushes against the protrusion 2 c with its piston rod, and one of the gripping jaws 2 . One of the holding cylinders 1 a may be seen inside the gripping jaw 2 . Also illustrated is a pipe 70 , which has just been gripped by the gripping jaw 2 after the gripping cylinder 5 has advanced this towards the pipe 70 .
[0055] FIG. 5 shows a possible example of an embodiment of the hydraulic connection for the gripping function of the rotation unit, and also shows a connection for the rotational function. In the figure, components located on the rotary part 40 of the rotation unit 65 are drawn within a line 30 . Components outside this are located on the fixed part 41 .
[0056] On the rotary part 40 are jaws 1 , 2 , 3 , which are designed to grip and hold a pipe 70 , as described above.
[0057] The jaws 1 , 2 , 3 are connected to the respective holding cylinder 1 a , 2 a , 3 a . The piston sides of the cylinders 1 a , 2 a , 3 a are connected to respective valve assemblies 10 , 11 , 12 via respective connecting lines 1 b , 2 b , 3 b . The valve assemblies 10 , 11 , 12 comprise a check valve 10 a , 11 a , 12 a , that opens for hydraulic communication with the respective holding cylinder 1 a , 2 a , 3 a when the hydraulic fluid is at a certain pressure and stops communication in the opposite direction, and the two-way relief valve 10 b , 11 b , 12 b , which is mentioned in connection with FIG. 3 , and which in a first position provides communication with the piston side of the respective holding cylinder 1 a , 2 a , 3 a and stops communication in the opposite direction, and in a second position opens for communication both ways.
[0058] The respective check valve 10 a , 11 a , 12 a communicates with the piston side of a slave cylinder 18 via a respective line 10 c , 11 c , 12 c . Preferably, three mechanically connected slave cylinders 18 are provided, but only one is shown in FIG. 5 . The respective two-way valve 10 b , 11 b , 12 b also communicates with the piston side of the slave cylinder 18 , via a respective line 10 d , 11 d , 12 d and a common check valve 20 , which opens for hydraulic communication with the slave cylinder 18 at a certain hydraulic pressure and stops communication in the opposite direction. The lines 10 d , 11 d , 12 d also communicate with a common hydraulic reservoir 16 .
[0059] The two-way valves 10 b , 11 b , 12 b are operated by a relief actuator 56 that acts on the valves 10 b , 11 b , 12 b via a first plate 57 on the fixed part and a second plate 58 on the rotary part. As shown in FIG. 3 , there are preferably at least three relief actuators 56 .
[0060] The rod side of the slave cylinder 18 communicates with the piston side of the same cylinder 18 via a valve 21 . The valve 21 comprises a check valve 21 a , which opens for communication from the piston side to the rod side and stops communication in the opposite direction, and a choke 21 b that allows limited hydraulic communication from the rod side to the piston side. The slave cylinder is equipped with a return spring 18 a that acts to push the piston 18 b towards the rod side.
[0061] The rod sides of the holding cylinders 1 a , 2 a , 3 a communicate with respective valves 13 , 14 , 15 . Each valve 13 , 14 , 15 comprises a check valve 13 a , 14 a , 15 a that opens for communication from the piston side of the respective holding cylinder 1 a , 2 a , 3 a and stops communication in the opposite direction, and a choke 13 b , 14 b , 15 b that allows limited hydraulic communication with the rod side. The valves 13 , 14 , 15 further communicate with a common accumulator 17 .
[0062] On the fixed part 41 is a hydraulic cylinder 19 , which in the following is denoted a master cylinder 19 . The master cylinder will, upon actuation and when the slave cylinder 18 is in the correct position for this, use its piston rod 19 a to push against the piston rod 18 c of the slave cylinder 18 .
[0063] When the rotary part 40 is located in such a position as to leave the master cylinder 19 and the slave cylinder 18 facing each other operationally, a respective gripping cylinder 4 , 5 , 6 will also be located operationally straight opposite the protrusion 1 c , 2 c , 3 c (not shown in FIG. 5 ) on a respective jaw 1 , 2 , 3 . The three gripping cylinders 4 , 5 , 6 will, upon actuation in this position, move the jaws 1 , 2 , 3 to engage the pipe.
[0064] On the piston side, the gripping cylinders 4 , 5 , 6 are hydraulically connected to a respective slave cylinder 31 , 32 , 33 . The pipe 70 is closer to the gripping jaw 6 . The slave cylinders 31 , 32 , 33 are actuated via a synchronizing element 36 of a synchronizing cylinder 34 , which is connected to a pump (not shown) via a load holding valve assembly 35 . The cylinder 32 is shorter than cylinders 31 and 33 , as the gripping cylinder 5 will displace its gripping jaw 2 over a shorter distance to engage the pipe, as explained in connection with FIG. 3 .
[0065] The piston sides of the gripping cylinders are connected to the pump (not shown) via a respective load holding valve assembly 7 , 8 , 9 .
[0066] The hydraulic motors 51 are connected to a pump (not shown) capable of driving the motors 51 in one direction or the other. Each motor 51 is connected to a respective cogwheel 50 via a gear 37 . Also shown is a mechanical brake 38 operable via valve assemblies 39 a , 39 b.
[0067] The principle of operation of the hydraulic connection in FIG. 5 will now be explained in greater detail.
[0068] In order to activate the three gripping jaws 1 , 2 , 3 , which form part of the rotary part of the tong, use is made of the three gripping cylinder 4 , 5 , 6 , which are activated and positioned synchronously via synchronizing cylinder 34 and slave cylinders 31 , 32 , 33 . Preferably, the synchronizing cylinder receives hydraulic power from the ring main or a stand-alone hydraulic motor-driven pump, which may be disposed on the tong or near this. The gripping cylinders are controlled by means of the hydraulic load holding valve assemblies 7 , 8 , 9 and synchronized by the synchronizing cylinder 34 being driven towards the three slave cylinders 31 , 32 , 33 , which are mechanically interconnected via the synchronizing element 36 . The slave cylinders 31 , 32 , 33 are connected to the gripping cylinders 4 , 5 , 6 , so that when the synchronizing cylinder 34 is driven towards the slave cylinders 31 , 32 , 33 , a hydraulic volume flow will be transferred from the respective slave cylinders 31 , 32 , 33 to the respective gripping cylinders 4 , 5 , 6 , achieving a synchronized movement of the gripping cylinders.
[0069] Movement and positioning of the gripping jaws is performed by running the respective gripping cylinders against the protrusion 1 c , 2 c , 3 , c on the jaws 1 , 2 , 3 , the jaws thus being pulled out towards the centre of the cavity 44 until they meet the pipe 70 . The gripping cylinders will keep the jaws at a standstill, pressing against the pipe 70 .
[0070] When the jaws are pulled towards the pipe, they also pull three holding cylinders 1 a , 2 a , 3 a with them, sucking hydraulic oil from the open reservoir 16 through the valve assembly 10 , 11 , 12 and into the piston side of the holding cylinders 1 a , 2 a , 3 a . The valves 10 b , 11 b , 12 b are then in the position shown in FIG. 1 , in which oil is permitted to flow past in the direction of the holding cylinders 1 a , 2 a , 3 a , but is not allowed to flow away from these. The hydraulic oil on the rod side of the holding cylinders 1 a , 2 a , 3 a is evacuated through the valves 13 , 14 , 15 to the accumulator 17 .
[0071] In order to increase the clamping force between the gripping jaws and the pipe a volume of oil is delivered to the piston side of the holding cylinders 1 a , 2 a , 3 a . Since the added volume of oil does not generate any movement of the gripping jaws, this added volume of oil will cause the pressure, and consequently the clamping force, to increase. The delivery of this volume of oil is achieved by the master cylinder 19 , which is disposed on the fixed part of the tong, pressing against the slave cylinder 18 , which is disposed on the rotary part of the tong. This volume of oil flows to the holding cylinders 1 a , 2 a , 3 a via the valves 10 a , 11 a , 12 a . The pressure in the master cylinder 19 is regulated by means of a pressure transmitter in a closed loop with a proportional directional valve (not shown). Since the gear ratio between the master cylinder 19 and the slave cylinder 18 is constant, the pressure in the holding cylinders 1 a , 2 a , 3 a can easily be controlled. Upon reaching the desired pressure, the master cylinder 19 returns to the initial position. When the cylinder 19 returns, the cylinder 18 will follow, due to the return spring 18 a , and oil will flow from the rod side of the cylinder 18 to the piston side via the valve assembly 21 . At the same time, the cylinder 18 will also be refilled from the reservoir 16 via the check valve 20 . As the valve assemblies 10 , 11 and 12 stop oil flowing away from the holding cylinders 1 a , 2 a , 3 a , these will maintain their clamping force against the pipe.
[0072] When the gripping cylinders 4 , 5 , 6 are also brought back to their initial positions, the tong may rotate freely with the pipe until the desired torque has been obtained. The tong can be rotated as shown by means of hydraulic motors, impellers and chains. The torque is regulated by a closed control loop with torque feed-back from the fixture for the fixed part of the tong and a proportional valve (not shown) connected to the hydraulic motors 51 .
[0073] The pipe is disengaged from the gripping jaws 1 , 2 , 3 by operating the relief actuator 56 , which via plates 57 and 58 displaces the valve 10 b , 11 b , 12 b in the valve assembly 10 , 11 , 12 to the position that allows communication in both directions. Thus the pressure will be relieved from the piston side of the holding cylinders 1 a , 2 a , 3 a , relieving the pressure of the gripping jaws. The accumulator 17 , which is connected to the rod side of the holding cylinders 1 a , 2 a , 3 a , delivers pressure to the rod side of the holding cylinders 1 a , 2 a , 3 a through choke 13 b , 14 b , 15 b . This pressure ensures that the holding cylinders are returned to their initial position. The chokes 13 b , 14 b , 15 b will control the speed of this return stroke.
[0074] FIG. 6 is a simplified view of an alternative hydraulic connection. Here the reservoir 16 has been removed. The accumulator 17 may be a bladder accumulator filled with nitrogen, as shown, or a piston accumulator. Instead of a return spring in the slave cylinder 18 , each holding cylinder 1 a , 2 a , 3 a is equipped with a return spring 1 c , 2 c , 3 c . When the two-way valves 10 b , 11 b , 12 b are open, these return springs will push the pistons of the holding cylinders back, thereby forcing the hydraulic fluid back to the slave cylinder 18 and returning this. The accumulator 17 will also contribute to this. Thus there will be no requirement for a return spring in the holding cylinder.
[0075] An alternative solution for increasing the clamping force between the pipe and the gripping jaws after the gripping cylinders have moved these to engage the pipe, is shown in FIG. 7 . Instead of using the hydraulic arrangement shown to supply hydraulic power to the holding cylinder, use is here made of the gripping cylinders 4 , 5 , 6 ( FIGS. 7 a, b, c show only one 4 of the cylinders) to push against an arm 80 connected to a tappet 81 on the gripping jaw 1 . In FIG. 7 a the jaw 1 is fully retracted, and the gripping cylinder 4 is ready to push on the arm 80 . In a first phase (see FIG. 7 b ) the gripping cylinder pushes against the arm 80 but without rotating this about the tappet 81 . This will move the jaw 1 towards the pipe 70 to engage this. At the same time, the holding cylinder 1 a is pulled along. The holding cylinder sucks hydraulic fluid from a reservoir (not shown). After the jaw 1 has engaged the pipe 70 and no further displacement of the jaw 1 is possible, the gripping cylinder will start to rotate the arm 80 about the tappet 81 . This will cause the tappet 81 to attempt to lengthen the gripping jaw 1 . However, this is not possible in the direction of the pipe 70 , and so the piston rod and piston of the holding cylinder 1 a will be forced into the actual cylinder while the centre line 82 of the holding cylinder and the piston rod is rotated over the centre of rotation 83 of the tappet. This will reduce the available volume for the limited quantity of oil in the holding cylinder 1 a , thus increasing the pressure. The force required by the gripping cylinder 4 to rotate the arm with the tappet 81 and the position of the arm 80 will be related to the pressure in the holding cylinder 1 a , allowing the clamping force between the pipe 70 and the gripping jaws to be determined and controlled. When the force from the gripping cylinders stops acting on the arm 80 , the net force from the pressure against the piston of the holding cylinder 1 a will attempt to displace the piston forward in the actual cylinder, but as the holding cylinder has rotated about its fixture in the actual cylinder, over the centre of rotation, it will be mechanically locked. The holding cylinder will therefore act as a hydraulic spring.
[0076] For the embodiment of FIG. 7 , a simplified hydraulic arrangement may be used, which includes no master and slave cylinders, but which will include valves for relieving hydraulic pressure from the holding cylinders, in accordance with the principles illustrated in FIGS. 5 and 6 .
[0077] Return of the jaws can be achieved e.g. by opening a valve (equivalent to valves 10 b , 11 b , 12 b ) that relieves the pressure from the holding cylinders. The jaws will be retracted, either by means of a return spring or by hydraulic pressure. The arm 80 with the tappet 81 may be equipped with a return spring (not shown) to bring it back to its initial position. Alternatively, the return of the arm 80 can be brought about through gravity alone.
[0078] An alternative embodiment for synchronization of the gripping cylinders would be to have position measurement for each gripping cylinder with separate proportional valves, to allow the gripping cylinders to be individually positioned and thereby synchronized.
[0079] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | A rotation unit for a torque tong for making and/or breaking threaded connections between pipes and/or spinning pipes during screwing and/or unscrewing of pipes, primarily pipes used in petroleum production. The unit includes a fixed part and a rotary part arranged to grip a pipe to be rotated. The rotary part includes at least one movable gripping jaw arranged to be moved into engagement with the pipe. The rotary part includes toothing arranged to engage at least one chain, which chain is operatively connected to an actuator in order to move the chain and so impart rotary movement to the rotary part. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of application Ser. No. 09/750,040, filed Dec. 29, 2000; which is a continuation of application Ser. No. 09/428,925, filed Oct. 28, 1999, now U.S. Pat. No. 6,198,665; which is a continuation of application Ser. No. 09/303,442, filed May 3, 1999, now U.S. Pat. No. 6,028,795; which is a continuation of Ser. No. 09/055,327, filed Apr. 6, 1998, now U.S. Pat. No. 5,923,591; which is a continuation of Ser. No. 08/853,713, filed May 9, 1997, now U.S. Pat. No. 5,781,479; which is a continuation of application Ser. No. 08/694,599, filed Aug. 9, 1996, now U.S. Pat. No. 5,719,809; which is a continuation of application Ser. No. 08/582,906, filed Jan. 4, 1996, now U.S. Pat. No. 5,615,155; which is a continuation of application Ser. No. 08/435,959, filed May 5, 1995, now U.S. Pat. No. 5,493,528; which is a continuation of application Ser. No. 08/294,407, filed Aug. 23, 1994, now U.S. Pat. No. 5,448,519; which is a continuation of application Ser. No. 07/855,843, filed Mar. 20, 1992, now U.S. Pat. No. 5,450,342; which is a continuation-in-part of application Ser. No. 07/349,403, filed May 8, 1989, now U.S. Pat. No. 5,175,838; which is a continuation of application Ser. No. 07/240,380, filed Aug. 29, 1988, now U.S. Pat. No. 4,868,781; which is a continuation of application Ser. No. 06/779,676, filed Sep. 24, 1985, now abandoned; said U.S. Pat. No. 4,868,781 being reissued by application Ser. No. 07/542,028, filed Jun. 21, 1990 now Pat. No. Re. 33,922; said application Ser. No. 07/855,843, filed Mar. 20, 1992, now U.S. Pat. No. 5,450,342 also being a continuation-in-part of Ser. No. 07/816,583, filed Jan. 3, 1992, now abandoned; which is a continuation of application Ser. No. 07/314,238, filed Feb. 22, 1989 now U.S. Pat. No. 5,113,487; which is a continuation of application Ser. No. 06/864,502, filed May 19, 1986, now abandoned, said application Ser. No. 07/816,583, filed Jan. 3, 1992, now abandoned, also being a continuation-in-part of application Ser. No. 07/349,403, filed May 8, 1989 now U.S. Pat. No. 5,175,383; which is a continuation of application Ser. No. 06/779,676, filed Sep. 24, 1985, now abandoned.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a memory device, and in particular, to a memory device suitable for a graphic memory to be utilized in high-speed image processing.
[0003] The prior art technique will be described by referring to graphic processing depicted as an example in FIG. 1- 2 . For example, the system of FIG. 1 comprises a graphic area M 1 having a one-to-one correspondence with a cathode ray tube (CRT) screen, a store area M 2 storing graphic data to be combined, and a modify section FC for combining the data in the graphic area M 1 with the data in the store area M 2 . in FIG. 2, a processing flowchart includes a processing step S 1 for reading data from the graphic area M 1 , a processing step S 2 for reading data from the store area M 2 , a processing step S 3 for combining the data read from the graphic area M 1 and the data read from the store area M 2 , and a processing step S 4 for writing the composite data generated in the step S 3 in the graphic area M 1 .
[0004] In the graphic processing example, the processing step S 3 of FIG. 2 performs a logical OR operation only to combine the data of the graphic area M 1 with that of the store area M 2 .
[0005] On the other hand, the graphic area M 1 to be subjected to the graphic processing must have a large memory capacity ranging from 100 kilobytes to several megabytes in ordinary cases. Consequently, in a series of graphic processing steps as shown in FIG. 2, the number of processing iterations to be executed is on the order of 106 or greater even if the processing is conducted on each byte one at a time.
[0006] Similarly referring to FIGS. 2 - 3 , graphic processing will be described in which the areas M 1 and M 2 store multivalued data such as color data for which a pixel is represented by the use of a plurality of bits.
[0007] Referring now to FIG. 3, a graphic processing arrangement comprises a memory area M 1 for storing original multivalued graphic data and a memory area M 2 containing multivalued graphic data to be combined therewith.
[0008] For the processing of multivalued graphic data shown in FIG. 3, addition is adopted as the operation to ordinarily generate composite graphic data. As a result, the values of data in the overlapped portion become larger, and hence a thicker picture is displayed as indicated by the crosshatching. in this case, the memory area must have a large memory capacity. The number of iterations of processing from the step S 1 to the step S 4 becomes on the order of 10 6 or greater, as depicted in FIG. 2. Due to the large iteration count, most of the graphic data processing time is occupied by the processing time to be elapsed to process the loop of FIG. 2. In graphic data processing, therefore, the period of time utilized for the memory access becomes greater than the time elapsed for the data processing. Among the steps S 1 -S 4 of FIG. 2, three steps S 1 , S 2 , and S 4 are associated with the memory access. As described above, in such processing as graphic data processing in which memory having a large capacity is accessed, even if the operation speed is improved, the memory access time becomes a bottleneck of the processing, which restricts the processing speed and does not permit improving the effective processing speed of the graphic data processing system.
[0009] In the prior art examples, the following disadvantages take place.
[0010] (1) In the graphic processing as shown by-use of the flowchart of FIG. 2, most of the processing is occupied by the steps S 1 , S 2 , and S 4 which use a bus for memory read/write operations consequently, the bus utilization ratio is increased and a higher load is imposed on the bus.
[0011] (2) The graphic processing time is further increased, for example, because the bus has a low transfer speed, or the overhead becomes greater due to the operation such as the bus control to dedicatedly allocate the bus to CRT display operation and to memory access.
[0012] (3) Moreover, although the flowchart of FIG. 2 includes only four static processing steps, a quite large volume of data must be processed as described before. That is, the number of dynamic processing steps which may elapse the effective processing time becomes very large, and hence a considerably long processing time is necessary.
[0013] Consequently, it is desirable to implement a graphic processing by use of a lower number of processing steps.
[0014] A memory circuit for executing the processing described above is found in the Japanese Patent Unexamined Publication No. 55-129387, for example.
[0015] Recent enhanced resolution of graphic display units is now demanding a large-capacity memory for use as a frame buffer for holding display information. In displaying a frame of graphic data, a large number of access operations to a capacious frame buffer take place, and therefore high-speed memory read/write operations are required. A conventional method for coping with this requirement is the distribution of processings.
[0016] An example of the distributed process is to carry out part of the process with a frame buffer. FIG. 26 shows, as an example, the arrangement of the frame buffer memory circuit, used in the method. The circuit includes an operation unit 1 , a memory 2 , an operational function control register 23 , and a write mask register 26 . The frame buffer writes data in bit units regardless of the word length of the memory device. On this account, the frame buffer writing process necessitates to implement operation and writing both in bit units. In the example of FIG. 26 , bit operation is implemented by the operation unit I and operational function control register 23 , while bit writing is implemented by the mask register 6 only to bits effective for writing. This frame buffer is designed to implement the memory read-modify-write operation in the write cycle for data D from the data processor, eliminating the need for the reading of data DO out of the memory, which the usual memory necessitates in such operation, whereby speedup of the frame buffer operation is made possible.
[0017] [0017]FIG. 27 shows another example of distributed processing which is applied to a graphic display system consisting of two data processors 20 and 20 ′, linked through a common bus 21 with a frame buffer memory 9 ″. The frame buffer memory 9 ″ is divided into two areas a and b which are operated for display by the data processors 20 and 20 ′, respectively. FIG. 28 shows an example of a display made by this graphic system. The content of the frame buffer memory 9 ″ is displayed on the CRT screen, which is divided into upper and lower sections in correspondence with the divided memory areas a and b as shown in FIG. 28. When it is intended to set up the memory 9 ″ for displaying a circle, for example, the data processor 20 produces an arc aa′a″ and the data processor 20 ′, produces a remaining arc bb′b″ concurrently. The circular display process falls into two major processings of calculating the coordinates of the circle and writing the result into the frame buffer. In case the calculation process takes a longer time than the writing process, the use of the two processors 20 and 201 for the process is effective for the speedup of display. If, on the other hand, the writing process takes a longer time, the two processors conflict over the access to the frame buffer memory 9 ″, resulting in a limited effectiveness of the dual processor system. The recent advanced LSI technology has significantly reduced the computation time of data processors relative to the memory write access time, which fosters the use of a frame buffer memory requiring less access operations such as one 9 ′ shown in FIG. 26.
[0018] In application of the frame buffer memory 9 ′ shown in FIG. 26 to the display system shown in FIG. 27, when both processors share in the same display process as shown in FIG. 28, the memory modification function is consistent for both processors and no problem will arise. In another case, however, if one processor draws graphic display a′ and another processor draws character display b′ as shown in FIG. 29, the system is no longer uneventful. In general, different kinds of display are accompanied by different memory modification operations, and if two processors make access to the frame buffer memory alternately, the setting for the modification operation and the read-modify-write operation need to take place in each display process. Setting for modification operation is identical to memory access when seen from the processor, and such double memory access ruins the attempt of speedup.
[0019] A conceivable scheme for reducing the number of computational settings is the memory access control in which one processor makes access to the frame buffer several times and then hands over the access right to another processor, instead of the alternate memory access control. However, this method requires additional time for the process of handing over the access right between the processors as compared with the display process using a common memory modification function. Namely, the conventional scheme of sharing in the same process among more than one data processor as shown in FIG. 28 is recently shifting to the implementation of separate processes as shown in FIG. 29 with a plurality of data processors as represented by the multi-window system, and the memory circuit is not designed in consideration of this regard.
[0020] An example of the frame buffer using the read-modify-write operation is disclosed, for example, in an article entitled “Designing a 1280-by-1024 pixel graphic display frame buffer in a 64K RAM with nibble mode”, Nikkei electronics, pp. 227-245, published on Aug. 27, 1984.
SUMMARY OF THE INVENTION
[0021] It is therefore an object of the present invention to-provide a method for storing graphic data and a circuit using the method which enables a higher-speed execution of dyadic and arithmetic operations on graphic data.
[0022] Another object of the present invention is to provide a memory circuit which performs read, modify, and write operations in a write cycle so that the number of dynamic steps is greatly reduced in the software section of the graphic processing.
[0023] Still another object of the present invention is to provide a memory circuit comprising a function to perform the dyadic and arithmetic operations so as to considerably lower the load imposed on the bus.
[0024] Further another object of the present invention is to provide a memory circuit which enables easily to implement a priority processing to be effected when graphic images are overlapped.
[0025] Further another object of the present invention is to provide a memory circuit with logical functions for use in constructing a frame buffer suitable for the multiple processors, parallel operations with the intention of realizing a high-speed graphic display system.
[0026] According to the present invention, there is provided a memory circuit having the following three functions to effect a higher-speed execution of processing to generate composite graphic data.
[0027] (1) A function to write external data in memory elements.
[0028] (2) A function to execute a logical operation between data previously stored in memory elements and external data, and to write the resultant data in the memory elements.
[0029] (3) A function to execute an arithmetic operation between data previously stored in memory elements and external data and to write the resultant data, in the memory elements.
[0030] A memory circuit which has these functions and which achieves a portion of the operation has been, implemented with emphasis placed on the previous points.
[0031] Also, many operations other than processing to generate composite multivalued graphic data as described above, a dyadic logic operation is required in which two operands are used. That is, the operation format is as follows in such cases.
[0032] D−D op s; where op stands for operator. On the other hand, the polynomial operation and multioperand operation as shown below are less frequently used.
D−S
j
op . . . opS
n
[0033] when the dyadic and two-operand operation is conducted between data in a central processing unit (CPU) an data in the memory elements, memory elements need be accessed only once if the operation result is to be stored in a register of the CPU (in a case where the D is a register and the S is a unit of memory elements) Contrarily, if the D indicates the memory elements unit and the S represents a register, the memory elements unit must be accessed two times. In most cases of data Processing including the multivalued graphic data processing, the number of data items is greater than the number of registers in the CPU; and hence the operation of the latter case where the D is the data element unit is frequently used; furthermore, each of two operands is stored in a memory element unit in many cases. Although the operation to access the S is indispensable to read the data, the D is accessed twice for read and write operations, that is, the same memory element unit is accessed two times for an operation.
[0034] To avoid this disadvantageous feature, the Read-Modify-Write adopted in the operation to access a dynamic random access memory (DRAM) is utilized so as to provide the memory circuit with an operation circuit so that the read and logic operations are carried out in the memory circuit, whereby the same memory element unit is accessed only once for an operation. The graphic data is modified in this fashion, which unnecessitates the operation to read the graphic data to be stored in the CPU and reduces the load imposed on the bus.
[0035] In accordance with the present invention there is provided a unit of memory elements which enables arbitrary operations to read, write, and store data characterized by including a control circuit which can operate in an ordinary write mode for storing in the memory elements unit a first data supplied externally based on first data and second data in the memory elements unit, a logic operation mode for storing an operation result obtained from a logic operation executed between the first and second data, and an arithmetic operation mode for storing in the memory element unit result data obtained from an arithmetic operation executed between the first data and the second data.
[0036] In general, when it is intended to share a resource by a plurality of processors, the resource access arbitration control is necessary, and when it is intended for a plurality of processors to share in a process for the purpose of speedup, they are required to operate and use resources in unison. These controls are generally implemented by the program of each processor, and it takes some processing time. Resources used commonly among processors include peripheral units and a storage unit. A peripheral unit is used exclusively for a time period once a processor has begun its use, while the storage unit is accessed by processors on a priority basis. The reason for the different utilization modes of the resources is that a peripheral unit has internal sequential operating modes and it is difficult for the unit to suspend the process in an intermediate mode once the operation has commenced, while the storage unit completes the data read or write operation within the duration of access by a processor and its internal operational mode does not last after the access terminates.
[0037] When it is intended to categorize the aforementioned memory implementing the read-modify-write operation in the above resource classification, the memory is a peripheral unit having the internal modification function, but the internal operating mode does not last beyond the access period, and operates faster than the processor. Accordingly, the memory access arbitration control by the program of the low-speed processor results in an increased system overhead for the switching operation, and therefore such control must be done within the memory circuit. The memory circuit implementing the read-modify-write operation does not necessitate internal operating modes dictated externally and it can switch the internal states to meet any processor solely by the memory internal operation.
[0038] The present invention resides in a memory circuit including a memory device operative to read, write and hold data, an operator which performs computation between first data supplied from outside and second data read out of the memory device, means for specifying an operational function from outside, and means for controlling bit writing from outside, wherein the operational function specifying means issues a selection control signal to a selector which selects one of a plurality of operational function specifying data supplied from outside, and wherein the bit writing control means issues a selection control signal to a selector which selects one of a plurality of bit writing control data supplied from outside, so that a frame buffer memory which implements the read-modify-write operation can be used commonly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] [0039]FIG. 1 is a schematic block diagram for explaining an operation to generate a composite graphic image in a graphic data processing system.
[0040] [0040]FIG. 2 is a flowchart of processing applied to the prior art technique to generate composite graphic data.
[0041] [0041]FIG. 3 is a schematic block diagram for explaining multivalued graphic data processing.
[0042] [0042]FIG. 4 is a timing chart illustrating the ordinary operation of a memory.
[0043] [0043]FIG. 5 is an explanatory diagram of a memory having a logic function.
[0044] [0044]FIG. 6 is a table for explaining the operation modes of the memory of FIG. 5.
[0045] [0045]FIG. 7 is schematic circuit diagram for implementing the logic function.
[0046] FIGS. 8 - 9 are tables for explaining truth values in detail.
[0047] [0047]FIG. 10 is a block diagram depicting the configuration of a memory having a logic function.
[0048] [0048]FIG. 11 is a flowchart of processing to generate composite graphic data by use of the memory of FIG. 10.
[0049] [0049]FIG. 12 is an explanatory diagram of processing to generate composite graphic data by use of an EOR logic function.
[0050] FIGS. 13 - 14 are schematic diagrams for explaining the processing to generate composite graphic data according to the present invention.
[0051] [0051]FIG. 15 is an explanatory diagram of an embodiment of the present invention.
[0052] [0052]FIG. 16 is a table for explaining in detail the operation logic or the present invention.
[0053] [0053]FIG. 17 is a schematic circuit diagram of an embodiment of the present invention.
[0054] [0054]FIG. 18 is a circuit block diagram for explaining an embodiment applied to color data processing.
[0055] [0055]FIG. 19 is a block diagram illustrating a memory circuit of an embodiment of the present invention.
[0056] [0056]FIG. 20 is a table for explaining the operation modes of a control circuit.
[0057] [0057]FIG. 21 is a schematic diagram illustrating an example of the control circuit configuration.
[0058] [0058]FIG. 22 is a circuit block diagram depicting an example of a 4 -bit operational memory configuration.
[0059] [0059]FIGS. 23 a to 23 c are-diagrams for explaining an application example of an embodiment.
[0060] [0060]FIG. 24 is a schematic diagram for explaining processing to delete multivalued graphic data.
[0061] [0061]FIG. 25 is a block diagram showing the memory circuit embodying the present invention;
[0062] [0062]FIG. 26 is a block diagram showing the conventional memory circuit;
[0063] [0063]FIG. 27 is a block diagram showing the conventional graphic display system;
[0064] [0064]FIG. 28 is a diagram explaining a two processor graphic display;
[0065] [0065]FIG. 29 is a diagram showing a graphic display by one processor a character display by another processor;
[0066] [0066]FIG. 30 is a block diagram showing the multi-processor graphic display system embodying the present invention;
[0067] [0067]FIG. 31 is a table used to explain the operational function of the embodiment shown in FIG. 30;
[0068] [0068]FIG. 32 is a block diagram showing the arrangement of the conventional frame buffer memory;
[0069] [0069]FIG. 33 is a block diagram showing the arrangement of the memory circuit embodying the present invention;
[0070] [0070]FIG. 34 is a schematic logic diagram showing the write mask circuit in FIG. 33;
[0071] [0071]FIG. 35 is a diagram used to explain the frame buffer constructed using the memory circuit shown in FIG. 33;
[0072] [0072]FIG. 36 is a block diagram showing the arrangement of the graphic display system for explaining operation code setting according to this embodiment;
[0073] [0073]FIG. 37 is a timing chart showing the memory access timing relationship according to this embodiment;
[0074] [0074]FIG. 38 is a timing chart showing the generation of the selection signal and operation code setting signal based on the memory access timing relationship; and
[0075] [0075]FIG. 39 is a timing chart showing the memory write timing relationship derived from FIG. 37, but with the addition of the selection signal.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0076] Referring to the accompanying drawings, the following paragraphs describe embodiments of the present invention in detail.
[0077] [0077]FIG. 4 is a timing chart of a DRAM. First, the operation to access the memory will be briefly described in conjunction with FIG. 4. In this timing chart, ADR is an address signal supplied from an external device and WR indicates a write request signal. These two signals (ADR and WR) are fed from a microprocessor, for example. In addition, RAS is a row address strobe signal, CAS is a column address strobe signal, A indicates an address signal representing a column or row address generated in the timesharing fashion, WE stands for a write enable signal, and Z is a data item supplied from an external device (microprocessor). Excepting the Z signal, they are control signals generated by a DRAM controller, for example. The memory access outlined in FIG. 4 can be summarized as follows.
[0078] (i) As shown in FIG. 4, a memory access in a read/write cycle generally commences with a read cycle (I) and ends with a write cycle (III) due to a write enable signal, WE.
[0079] (ii) Between the read cycle (I) and the write cycle (III), there appears an interval (II) in which a read data Do and an external data Z (to be written) exist-simultaneously.
[0080] (iii) This interval (ii) is referred to as the operation enabled interval.
[0081] As described above, the store data Do and the external write data Z exist simultaneously in the interval (II). As a consequence, the store data Do and the external data Z can be subjected to an operation during a memory cycle in this interval by use of the memory circuit having an operation function, thereby enabling the operation result to be written in the memory circuit.
[0082] [0082]FIG. 5 is a block diagram illustrating a first embodiment of the present invention, FIG. 6 is an explanatory diagram of the operation principle of the embodiment shown in FIG. 5, FIG. 7 is a circuit example implementing the operation principle of FIG. 6, and FIG. 8 is a table for explaining in detail the operation of the circuit shown in FIG. 7.
[0083] The circuit configuration of FIG. 5 comprises a control logic circuit 1 , a unit of memory elements 2 , a DRAM controller 3 , external data X and Y, a write data Z to the memory elements unit 2 , a read data Do from the memory elements unit 2 , and signals A, CAS, RAST ADR, and WR which are the same as those described in conjunction with FIG. 4. The external data Z of FIG. 4 is replaced with the write data Z delivered via the control circuit to the memory elements unit 2 in FIG. 5.
[0084] In accordance with an aspect of the present invention as shown in FIG. 5, the control circuit I controls the read data Do by use of the external data signals X and Y, and the modified read data is written in the memory elements unit 2 . FIG. 6 is a table for explaining the control operation. In this table, mode I is provided to set the external data Y as the write data Z, whereas mode II is provided to set the read data Do as the write data Z. As shown in FIG. 6, the external data signals X and Y, namely, the external control is used to control two modes, that is, the read data of the memory elements unit 2 is altered and written (mode II), or the external data Y is written (mode I). For the control of two modes, (i) mode I or II is specified by the external data X and (ii) the modification specification to invert or not to invert the read data Do is made by use of an external data.
[0085] The control and modification are effected in the interval (II) described in conjunction with FIG. 4.
[0086] A specific circuit example implementing the operation described above is shown in FIG. 7.
[0087] The control logic circuit comprises an AND gate 10 and an EOR gate 11 and operates according to the truth table of FIG. 8, which illustrates the relationships among two external data signals X and Y, store data Do,—and output Z from the control circuit 1 .
[0088] As can be seen from FIG. 8, the control circuit 1 operates primarily in the following two operation modes depending on the external data X.
[0089] (i) When the external data X is ‘0’, it operates in the operation mode I in which the external data Y is processed as the write data Z.
[0090] (ii) When the external data X is ‘1’, it operates in the operation mode II in which the data obtained by modifying the read data Do based on the external data Y is used as the write data Z.
[0091] As already shown in FIG. 4, the operation above is executed during a memory cycle.
[0092] Consequently, the principle of-the present invention is described as follows.
[0093] (i) The output Do from the memory elements unit 2 is fed back as an input signal to the control circuit as described in conjunction with FIG. 4; and
[0094] (ii) The write data to, the memory elements unit 2 is controlled by use of the input data signals X and Y (generated from the write data from the CPU) as shown in FIG. 5.
[0095] These operations (i) and (ii) are executed during a, memory cycle. That is, a data item in the memory elements is modified with an external input data (namely, an operation is conducted between these two data items) during a memory cycle by use of three data items including (i) feedback data from the memory elements, (ii) data inputted from an external device, and (iii) control data from an external device (a portion of external input data is also used as the control data). These operations imply that an external device (for example, a graphic processing system, a CPU available at present, or the like) can execute a logic operation only by use of a write operation.
[0096] The operation of the circuit shown in FIG. 7, on the other hand, is expressed as follows
Z=X·Do Y+X·Do·Y=Do·Y+X·Y+X·Do·Y =( X+Y )· Do·Y+X·Y+X·DO·Y=X·Y+X ·( YÅDo ) (1)
[0097] Substituting the externally controllable data items X and Y with the applicable values of a signal “0”, a signal “1”, the bus data Di fed from the microprocessor, and the reversed data thereof appropriately Di, the operation results of the dyadic logic operations as shown in FIG. 9 will be obtained. FIG. 10. is a circuit diagram implemented by combining the dyadic operations of FIG. 9 with the processing system of the FIG. 5 embodiment. The system of FIG. 10 comprises four-input selectors SELf and SEL 1 , input select signals S 0 and S 1 to the selector SELf, input select signals S 2 and S 3 to the selector SEL 1 , and an inverter element INV.
[0098] Referring now to FIG. 1, and FIGS. 9 - 11 , an operation example of a logic operation will be specifically described.
[0099] As shown in FIG. 9, the input select signals S 0 and S 1 are used as the select signals of the selector SELf to determine the value of data X. Similarly, the input select signals S 2 and S 3 are used to determine the value of data Y. The values that can be set to these data items X and Y include a signal “0”, a signal “1”, the bus data Di, and the inverted data thereof Di as described before. The selectors SELf and SEL 1 each select one of these four signal values depending on the input select signals S 0 to S 3 as shown in FIG. 10. FIG. 9 is a table illustrating the relationships between the input select signals S 0 to S 3 and the data items X and Y outputted from the selectors SELf and SEL 1 , respectively, as well as the write data Z outputted from the control circuit 1 . In graphic processing as shown in FIG. 1 (OR operation: Case 1 ), for example, the data items X and Y are selected as Di and Di, respectively when the input select signals are set as follows: SO, SI=(11) and S z , S 3 =(10). Substituting these values of X and Y in the expression (1) representing the operation of the control circuit 1 , the OR operation, namely, Z=Di+Di Do=Di·(1+Do)+Di Do=Di+(Di+Di) Do=Di+Do is executed. In accordance with an aspect of the present invention, therefore, the graphic processing of FIG. 1 can be performed as shown in FIG. 11 in which the input select signals S 0 to S 1 are specified in the first step (function specification), a graphic data item to be combined is thereafter read from the storage area M 2 , and the obtained data item is stored in the graphic area only by use of a write operation.
[0100] Various logic functions can be effected by changing the values of S 0 to S 3 as depicted in FIG. 9. Consequently, an operation to draw a picture, for example, by use of a mouse cursor which is arbitrarily moved can be readily executed as shown in FIG. 12. Even when the mouse cursor (M 2 ) overlaps with a graphic image in the graphic area M 1 as illustrated in FIG. 12, the cursor must be displayed, and hence a function of the EOR operation is necessary. In this cursor display, when the input select signals are set as S 0 , S 1 =(10) and S 2 , S 3 =(01), the processing can be achieved as depicted in FIG. 11 in the same manner as the case of- the composite graphic 7 c data generation described before. The various logic functions as listed in the table of FIG. 9 can be therefore easily implemented; furthermore, the Read-Modify-Write operation on the memory element unit 2 can -be accomplished only by a write operation.
[0101] By use of the circuit configuration of FIG. 10, the dyadic logic operations of FIG. 9 can be executed as a modify operation to be conducted between the data Di from the microprocessor and the read data Do from the memory elements unit 2 . Incidentally, the input select signals are used to specify a dyadic logic operation.
[0102] In accordance with the embodiment described above, the prior art processing to generate a composite graphic image can be simplified as depicted by the flowchart of FIG. 11.
[0103] The embodiment of the present invention described above comprises three functions as shown in FIG. 10, namely, a memory section including memory elements unit 2 , a control section having the control circuit 1 , and a selector section including the selectors SEIA and SELI. However, the function implemented by a combination of the control and selector sections is identical to the dyadic logic operation function described in conjunction with FIG. 9. Although this function can be easily achieved by use of other means, the embodiment above is preferable to simplify the circuit configuration.
[0104] On the other hand, graphic processing is required to include processing in which graphic images and the like are overlapped as illustrated in FIGS. 13 14 . In the first case, the graphic image in the store area M 2 takes precedence over the graphic image in the graphic image area M 1 when they are displayed as depicted in FIG. 13. In the second case, the graphic image in the graphic image area M 1 takes precedence over the graphic image in the store area M 2 as shown in FIG. 14.
[0105] The priority processing to determine the priority of graphic data as illustrated in FIGS. 13 - 14 cannot be achieved only by the logical function implemented by the FC section of FIG. 10) described above.
[0106] This function, however, can be early implemented by use of the memory circuit in an embodiment of the present invention namely, only simple logic and selector circuits need by added to the graphic processing system. An embodiment for realizing such a function will be described by referring to FIGS. 15 - 17 . The FC section of FIG. 15 corresponds to a combination of the control circuit and the selectors SELf and SEL 1 . In this embodiment, the logic operation function (FC) section operates in the pass mode with the input select signals so to S 3 of the selectors SELf and SEL 1 set as (0, 0, 1, 0), for example.
[0107] The circuit block diagram of FIG. 15 includes a priority control section 4 , a two-input selector SEL 2 , a priority specification signal P, an input select signal S 4 to-the selector SEL 2 , a graphic data signal Di′ from the store area M 2 , a graphic image area M 1 , a selected signal Di from selector SEL 2 , a graphic data signal Do from the graphic image area M 1 (identical to the read data signal from the memory elements unit 2 shown in FIG. 10), and an output signal Z from the FC section (identical to the output signal from the control circuit I of FIG. 4). For the convenience of explanation, the graphic area is set to a logic value “1” and the background area is set to a logic value “0” as shown in FIG. 15. In this processing, the priority control section 4 and the selector SEL 2 operate according to the contents of the truth table of FIG. 16. The relation-ships between the input select signal S 4 and the input data Di to the logic operation function (FC) section are outlined in FIG. 16, where the signal S 4 is determined by a combination of the priority specification signal P, the data Di′ in the area M 2 , and the data Do from the area M 1 , and the input data Di is set by the signal S 4 .
[0108] In other words, the truth table of FIG. 16 determines an operation as follows. For example, assume that the graphic area to be used as the background is Mi. If the data items Do and Di′ in the areas M 1 and M 2 , respectively, are set to the effective data (“1”), the priority specification signal P is used to deter-mine whether the data Do of the background area M 1 takes precedence (P=1), or the data Di′ of the area M 2 takes precedence (P=0).
[0109] That is, if a graphic image in the store area M 2 is desired to be displayed over the graphic image of the graphic area M 1 , as illustrated in FIG. 13, the priority specification signal P is set to “0”. Then, if the graphic data items Di′ and Do, are in the graphic areas (“1”) as depicted in FIG. 15, the data Di′ of the store area M 2 is preferentially selected by the selector SEL 2 . If the priority specification signal P is set to “1”, the graphic processing is similarly executed according to the truth table of FIG. 16 as shown in FIG. 14.
[0110] In FIG. 16, if the graphic areas (“1”) are overlapped, the graphic area of the graphic area M 1 , or the store area M 2 , is selected depending on the priority specification signal P, and the data of the graphic area M 1 is selected as the background for the area in which the graphic area does not exist.
[0111] [0111]FIG. 17 is a specific circuit diagram of the priority control section 4 depicted in FIG. 15. In this circuit diagram, reference numerals 40 and 41 indicate a three-input NAND circuit and a two-input NAND circuit respectively.
[0112] In order to apply the principle of priority decision to color data in which each pixel comprises a plurality of bits, the circuit must be modified as illustrated in FIG. 18.
[0113] The circuit of FIG. 18 includes a compare and determine section 5 for determining the graphic area (COL 3 ) of the graphic area M 1 and a compare and determine section 6 for determining the graphic area (COL 1 ) of the store area M 1 . As described above, the priority comprises a plurality of bits, it is different from the circuit for processing information for which a pixel comprises a bit as shown in FIG. 15 in that the priority determination between significant data items is achieved by use of the code information (COLf to COL 3 ) because the graphic data is expressed by the code information.
[0114] Consequently, in the case of color data, the overlapped graphic images can be easily processed by adding the compare and determine sections which determine the priority by comparing the code information.
[0115] The preceding paragraphs have described the priority determine circuit applied to an embodiment of the memory circuit having an operation function, however, it is clear that such embodiment can be applied to a simple memory circuit, or a memory circuit which has integrated shift register and serial outputs.
[0116] In accordance with this embodiment, the following effect is developed.
[0117] (1) When executing the processing as shown in FIG. 1, the processing flowchart of FIG. 11 can be utilized, and hence the memory cycle can be minimized.
[0118] (2) Three kinds of processing including the read, modify, and write operations can be executed only during a write cycle, which enables an increase in the processing speed.
[0119] (3) As depicted in FIGS. 16 - 18 , the priority processing to be conducted when the graphic images are overlapped can be effected by the use of a plurality of simple logic gates.
[0120] ( 4 ) The graphic processing of color data can be also easily implemented by externally adding the compare and determine circuits for determining the graphic areas (code data comprising at least two bits).
[0121] ( 5 ) The size of the circuit configuration necessary for implementing the memory circuit according to the invention is quite small as compared with that of a group of memory elements, which is considerably advantageous to manufacture a large scale integration circuit in the same memory chip.
[0122] Next, another embodiment will be described in which processing to generate a composite graphic data represented as the multivalued data of FIG. 3 is executed.
[0123] [0123]FIG. 19 is a circuit block diagram of a memory circuit applied to a case in which multivalued data is processed. This circuit is different from the memory circuit of FIG. 5 in the configuration of a control circuit 1 ′.
[0124] The configuration of FIG. 19 is adopted because the processing to generate a composite graphic data from the multivalued data indispensably necessitates an arithmetic operation, not a simple logic operation. As shown in FIG. 19, however, the basic operation is the same as depicted in FIG. 5.
[0125] In the following paragraphs, although the arithmetic operation is described, the circuit configuration includes the sections associated with the logic operation because the logic operation is also used for the multivalued graphic data processing. The circuit arrangement of FIG. 19 includes a control circuit 11 , memory elements unit 2 , a DRAM controller 3 , external control signals CNT and Cr, data Y supplied from an external device, write data Z to the memory elements unit 2 , read data Do from the memory elements unit 2 , and signals A, WE, CAS, RAS, ADR, and WR which are the same as those shown in FIG. 5.
[0126] In the embodiment as shown in FIG. 19, the control circuit 11 performs an operation on the read data Do and the external data Y according to the external control signals CRT and Cr; and the operation result, write data Z is written in the memory elements 2 . FIG. 20 is a table illustrating the control operation modes of the control circuit 1 ′. When the external control signals CRT and Cr are set to f, the control circuit 1 ′ operates in a mode where the external data Y is used as a control signal to determine whether or not the read data Do is subjected to an inversion before it is outputted; when the signals CRT and Cr are set to 0 and 1, respectively, the control circuit 1 ′ operates in a mode where the external data Y is outputted without change; and when the signals are set to 1 , the control circuit 1 ′ operates in a mode where the read data Do, the external data Y, and the external control signal Cr are arithmetically added.
[0127] [0127]FIG. 21 is a specific circuit diagram of a circuit implementing the control operation modes. In this circuit arrangement, the arithmetic operation is achieved by use of the ENOR gates G 1 and G 2 , and the condition that the external control signals CRT and Cr are f and 1 , respectively is detected by the gates G 6 to G 8 , and the output from the ENOR gate or the external data Y is selected by use of a selector constituted from the gates G 3 to G 5 . This circuit configuration further includes a NAND gate G 9 for outputting a generate signal associated with the carry lookahead function provided to minimize the propagation delay of the carry and an AND gate GIO for generating a propagate signal similarly associated with the carry lookahead function. The logical expressions of the output signals Z, P, and G from the control circuit I′ are as listed in FIG. 21, where the carry lookahead signals P and G each are set to fixed values (P=0, G=1) if the external control signal CNT is f.
[0128] [0128]FIG. 22 is the configuration of a four-bit operation memory utilizing four memory circuits for the embodiment. For simplification of explanation, only the sections primarily associated with the arithmetic operation mode are depicted in FIG. 22. The circuit diagram includes the memory circuits 11 - 14 shown in FIG. 19, gates G 11 to G 28 constituting a carry lookahead circuit for achieving a carry operation, and a register F for storing the result of a carry caused by an arithmetic operation. The memory circuits 11 and 14 are associated with the least and most-significant bits, respectively.
[0129] Although not shown in this circuit configuration to simplify the circuit arrangement, the register F is connected to an external circuit which sets the content to f or 1 . The logical expression of the carry result, namely, the output from the gate G 29 is as follows.
G 4 + G 3 · P 4 + G 2 · P 3 · P 4 + G 1 · P 2 · P 3 · P 4 + Cr·P 1 · P 2 · P 3 · P 4
[0130] When the external control signal CNT is f, Pi and Gi are set to 1 and f, respectively (where, i indicates an integer ranging from one to four), and hence the logical expression includes only the signal Cr, which means that the value of the register F is not changed by a write operation. Since the intermediate carry signals Gr 2 to Gr 4 are also set to the value of the signal Cr, three operation states are not changed by a write operation when the external control signal CNT is f. If the external control signal CNT is 1, the carry control signals P 1 to P 4 and G 1 to G 4 of the memory circuits 11 - 14 , respectively function as the carry lookahead signals, so an ordinary addition can be conducted.
[0131] As shown in FIG. 20, although the control circuit has a small number of operation modes, the operation functions can be increased by selecting the logic value f, the logic value 1, the write data D to a microprocessor or the like, and the inverted data D of the write data D as the inputs Of the external control signal Cr and the external data Y.
[0132] [0132]FIGS. 23 a to 23 c illustrate an example in which the above-mentioned circuits are combined. FIG. 23 a is a specific representation of a circuit for the least significant bit, whereas FIG. 22 b is a table outlining the operation functions of the circuit of FIG. 23 a.
[0133] In the following paragraphs, the circuit operation will be described only in the arithmetic operation mode with the external control signal CNT set to 1.
[0134] Gates G 29 -G 33 constitute a selector (SEL 3 ) for the external control signal Cr, while gates G 34 -G 37 configure a selector (SEL 4 ) for the external data Y. The circuit arrangement of FIG. 23 a comprises select control signals Sf and S 1 for selecting the external control signal Cr and select control signals S 2 and S 3 for selecting the external data Y. FIG. 23 c depicts a circuit for the most-significant bit. This circuit is different from that of FIG. 23 a in that the selector for the signal Cr is constituted from the gates G 38 -G 44 so that a carry signal Cri-I from the lower-order bit is inputted to the external control signal Cr when the external control signal CNT is 1 . The selector for the external data Y is of the same configuration of that of FIG. 23 a. In the circuit configuration of FIG. 23 c, the memory circuit arrangement enables to achieve 16 kinds of logical operations and six kinds of arithmetic operations by executing a memory write access. For example, the processing to overlap multivalued graphic data as shown in FIG. 3 is carried out as follows. First, the select signals S 0 to S 3 are set to 0, 0, 0, and 1, respectively and the write data Z is specified for an arithmetic operation of Do Plus 1 . A data item is read from the multivalued graphic data memory M 2 and the obtained data item is written in the destination multivalued graphic data area M 1 , which causes each data to be added and the multivalued graphic data items are overlapped at a higher speed. Similarly, if the select signals Sf to S 3 are set to 1 and the write data Z is specified for a subtraction of Do Minus Di, the unnecessary portion (such as the noise) of the multivalued graphic data can be deleted as depicted in FIG. 24. Like the case of the overlap processing, this processing can be implemented only by executing a read operation on the data memory M 3 containing the data from which the unnecessary portion is subtracted and by repeating a write operation thereafter on the destination data memory M 3 , which enables higher-speed graphic processing.
[0135] According to the above embodiments,
[0136] (1) The multivalued graphic data processing is effected by repeating memory access two times, and hence the processing such as the graphic data overlap processing and subtraction can be achieved at a higher speed;
[0137] (2) Since the data operation conducted between memory units is implemented on the memory side, the multivalued graphic processing can be implemented not only in a device such as a microprocessor which has an operation function but also in a device such as a direct memory access (DMA) controller which has not an operation function; and
[0138] (3) The carry processing is conducted when a memory write access is executed by use of the circuit configuration as shown in FIG. 22, so the multiple-precision arithmetic operation can be implemented only by using a memory write operation, thereby enabling a multiple-precision arithmetic operation to be achieved at a higher speed.
[0139] It is also possible to perform the dyadic operation and the arithmetic operation on graphic data at a higher speed. Moreover, the priority processing to be utilized when graphic images overlap and processing for color data can be readily implemented.
[0140] [0140]FIG. 25 shows a frame buffer memory circuit including an operation unit (LU) 1 for implementing the modification functions for the read-modify-write operation, a data memory 2 , operational function specifying registers 23 and 24 for specifying an operational function of the operation unit, an operational function selector 25 for selecting an operational function, write mask registers 26 and 27 for holding write mask data, and a write mask selector 28 for selecting write mask data. Symbol D denotes write data sent over the common bus, and symbol C denotes a selection signal for controlling the operational function selector 5 and write mask selector 28 .
[0141] [0141]FIG. 30 is a block diagram showing the application of the inventive frame buffer memory circuit 9 shown in FIG. 25 to the multi-processor system, in which are included data processors 20 and 20 ′, a common bus 21 and an address decoder 22 .
[0142] The following describes, as an example, the operation of this embodiment. For clarification purposes, FIGS. 25 and 30 do not show the memory read data bus, memory block address decoder and read-modify-write control circuit, all of which are not essential for the explanation of this invention In this embodiment, the memory circuit 9 is addressed from 800000 H to 9 FFFFFH. The memory circuit 9 itself has a 1M byte capacity in a physical sense, but it is addressed double in the range 800000 H- 9 FFFFFH to provide a virtual 2M byte address space. The method of double addressing is such that address 800000 H and address 900000 H contain the same byte data, and so on, and finally address 8 FFFFFH and address 9 FFFFFH contain the same byte data. Accordingly, data read by the processor 20 at address 8 xxxxxH is equal to data read at address 9 xxxxxH, provided that the address-section xxxxx is common. The reason for double addressing the memory circuit 9 beginning with address 800000 H and address 900000 H is to distinguish accesses by the data processors 20 and 201 . Namely, the data processor 20 is accessible to a 1M byte area starting with 800000 H, while the-processor 20 , is accessible to a 1M byte area starting with 900000 H. The address decoder 22 serves to control the double addressing system, and it produces a “0” output in response to an address signal having an even (8H) highest digit, while producing a “1” output in response to an address signal having an odd (9H) highest digit.
[0143] The operation unit I has a function set of 16 logical operations as listed in FIG. 31. In order to specify one of the 16 kinds of operations, the operation code data FC is formatted in 4 bits, and the operational function specifying registers 23 and 24 and operational function selector 25 are all arranged in 4 bits. Since the memory 2 is of the 16-bit word length, the write mask registers 26 and 27 and mask selector 28 also have 16 bits.
[0144] Next, the operation of the data processor 20 in FIG. 30 in making write access to the frame buffer memory 9 will be described. The data processor 20 has a preset of function code FO in the operational function specifying register 23 and mask data MO in the write mask register 26 . When the data processor 20 makes write access to address 800000 H, for example. the memory access operation takes place in the order of reading, modifying and writing in the timing relationship as shown in FIG. 39. In response to the output of address 800000 H onto the address bus by the data processor 20 , the address decoder 22 produces a “O” output, the operational function selector 25 selects the operational function specifying register 23 , and the operation unit I receives F 0 as operation code data FC. At this time, the write mask selector 28 selects the write mask register 26 , and it outputs MO as WE to the memory 2 . In FIG. 39, data in address SOOOOOH is read out in the read period, which is subjected to calculation with write data D from the data processor 20 by the operation unit I in accordance with the calculation code data FO in the modification period, and the result is written in accordance with data MO in the write period. The write mask data inhibits writing at “0” and enables writing at “1”, and the data MO is given value FFH for the usual write operation.
[0145] When another data processor 20 ′ makes-access to the frame buffer 9 , function code F 1 is preset in the operational function specifying register 24 and mask data M 1 is preset in the write mask register 27 . In order for the data processor 201 to access the same data as one in address 800000 H for the data processor 20 , it makes write access to address 900000 H. The write access timing relationship for the data processor 201 is similar to that shown in FIG. 39, but differs in that the output signal C of the address decoder 22 is “1” during the access, the function code for modification is F 1 , and the write mask is M 1 in this case.
[0146] Accordingly, by making the data processors 20 and 20 ′ access different addresses, the calculation and mask data can be different, and the operational functions need not be set at each time even when the processors implement different display operations as shown in FIG. 29.
[0147] Next, the arrangement of the frame buffer memory 9 and the method of setting the operational function according to this embodiment will be described.
[0148] [0148]FIG. 32 shows a typical arrangement of the frame buffer. Conventionally, a memory has been constructed using a plurality of memory IC (Integrated Circuit) components with external accompaniments of an operation unit 1 , operational function specifying register 23 and write mask register 26 . The reason for the arrangement of the memory using a plurality of memory IC components is that the memory capacity is too large to be constructed by a single component. The memory is constructed divisionally, each division constituting 1, 3 or 4 bits or the like of data words (16-bit word in this embodiment). For example, when each division forms a bit of data words, at least 16 memory IC components are used. For the same reason when it is intended to integrate the whole frame buffer shown in FIG. 32, it needs to be divided into several IC components.
[0149] The following describes the method of this embodiment for setting the operational function and write mask data for the sliced memory structure. The setting method will be described on the assumption that a single operational function specifying register and write mask register are provided, since the plurality of these register sets is not significant for the explanation.
[0150] Currently used graphic display units are mostly arranged to have operational functions of logical bit operations, and therefore it is possible to divide the operation unit into bit groups of operation data. It is also possible in principle to divide the operation unit on a bit slicing basis also for the case of implementing arithmetic operations, through the additional provision of a carry control circuit. The write mask register 26 is a circuit controlling the write operation in bit units, and therefore it can obviously be divided into bit units. The operational function specifying register 23 stores a number in a word length determined from the type of operational function of the operation unit 1 , which is independent of the word length of operation data (16 bits in this embodiment), and therefore it cannot be divided into bit groups of operation data. On this account, the operational function specifying register 23 needs to be provided for each divided bit group. Although it seems inefficient to have the same functional circuit for each divided bit group, the number of elements used for the peripheral circuits is less than 1% of the memory elements, and the yearly increasing circuit integration density makes this matter insignificant. However, in contrast to the case of slicing the operational function specifying register 23 into bit groups, partition of the frame buffer-shown in FIG. 32 into bit groups of data is questionable. The reason is that the operational function specifying register 23 is designed to receive data signals D 15 -DO. When the frame buffer is simply sliced into 1-bit groups, the operational function specifying register 23 can receive 1-bit data and it cannot receive a 4-bit specification code listed in FIG. 31. If, on the other hand, it is designed to supply a necessary number of 1-bit signals to the operational function specifying register 23 , the frame buffer must have terminals effective solely for the specification of operational functions, and this will result in an increased package size when the whole circuit is integrated. If it is designed to specify the operational function using the data bus, the number of operational functions becomes dependent on bit slicing of data, and to avoid this the frame memory of this embodiment is intended to specify operational functions using the address but which is independent of bit slicing.
[0151] [0151]FIG. 33 shows, as an example, the arrangement of the frame buffer memory which uses part of the address signals for specifying operational functions. Symbol Dj denotes a 1-bit signal in the 16-bit data signals to the graphic display data processor, A 23 -A 1 are address signals to the data processor, WE is the write control signal to the data processor, FS is the data setting control signal for the operational function specifying register 3 and write mask register 26 , DOj is a bit of data read out of the memory device 2 , DIj is a bit of data produced by the operation unit 1 , and Wj is the write control signal to the memory device 2 .
[0152] [0152]FIG. 34 shows, as an example, the arrangement of the write mask register, which includes a write mask data register 61 and a gate 62 for disabling the write control signal WE.
[0153] [0153]FIG. 35 shows the arrangement of the frame buffer constructed by using the memory circuit shown in FIG. 33. The figure shows a 4-bit arrangement for clarifying the connection to each memory circuit.
[0154] [0154]FIG. 36 shows the memory circuit of this embodiment applied to a graphic display system, with the intention of explaining the setting of the operation code. Reference number 20 denotes a data processor, and 23 denotes a decoder for producing the set signal FS.
[0155] The following describes the operation of the memory circuit. In this embodiment, an address range 800000 H- 9 FFFFFH is assigned to the memory circuit 9 . The decoder 23 produces the set signal FS in response to addresses AOOOOOH-AOOOIFH. The operation unit 1 has the 16 operational functions as listed in FIG. 31.
[0156] When the data processor 20 operates to write data FOFFH in address A 00014 H, for example, the decoder 23 produces the set signal FS to load the address bit signals A 4 -A 1 , i.e., 0101B (B signifies binary), in the operational function specifying register 3 . Consequently, the operation unit 2 selects the logical-sum operation in compliance with the table in FIG. 31. In the write mask register 26 , a bit of 16-bit data OFOOH from the data processor 20 , the bit position being the same as the bit position of the memory device, is set in the write mask data register 61 . As a result, FOFFH is set as write mask data.
[0157] Next, the operation of the data processor 20 for writing F 3 FFH in address 800000 H will be described. It is assumed that the address BOOOOOH has the contents of 0512 H in advance. FIG. 37 shows the timing relation-ship of memory access by the data processor 10 . The write access to the memory circuit 9 by the data processor 20 is the read-modify-write operation as shown in FIG. 37. In the read period of this operation, data 0512 H is read out onto the DO bus, and the D bus. receives F 3 FFH. In the subsequent modification period, the operation unit 1 implements the operation between data on the D bus and DO bus and outputs the operation result onto the DI bus. In this example, the D bus carries F 3 FFH and the DO bus carries 0512 H, and the DI bus will have data F 7 FFH as a result of the logical-sum operation which has been selected for the operation unit 1 . Finally, in the write period of the read-modify-write operation, data F 7 FFH on the DI bus is written in the memory device. In this case, FOFFH has been set as write mask data by the aforementioned setting operation, and a “0” bit of mask data enables the gate 62 , while “1” bit disables the gate 62 as shown in FIG. 34, causing only 4 bits (D 11 -D 8 ) to undergo the actual write operation, with the remaining 12 bits being left out of the write operation. Consequently, data in address 800000 H is altered to 0712 H.
[0158] The foregoing embodiment of this invention provides the following effectiveness. Owing to the provision of the operation specifying registers 23 and 24 and the write mask registers 26 and 27 in correspondence to the data processors 20 and 20 ′, specification of a modification function for the read-modify-write operation and mask write specification are done for each data processor even in the case of write access to the frame buffer memory 9 by the data processors 20 and 20 ′ asynchronously and independently, which eliminates the need for arbitration control between the data processors, whereby both processors can implement display processings without interference from each other except for an access delay caused by conflicting accesses to the frame buffer memory 9 .
[0159] The above embodiment is a frame buffer memory for a graphic display system, and the data processors 20 and 20 ′ mainly perform the coordinate calculations for pixels. The two data processors can share in the coordinate calculation and other processes in case they consume too much time, thereby reducing the processing time and thus minimizing the display wait time. For the case of a time-consuming frame buffer write processing, the use of the read-modify-write operation reduces the frequency of memory access, whereby a high-speed graphic display system operative with a minimal display wait time can be realized.
[0160] The above embodiment uses part of the address signal for the control signal, and in consequence a memory-circuit operative in read-modify-write mode with the ability of specifying the operational function independent of data slicing methods can be realized. On this account, when all functional blocks are integrated in a circuit component, the arrangement of the memory section can be determined independently of the read-modify-write function.
[0161] Although in the foregoing embodiment two data processors are used, it is needless to say that a system including three or more data processors can be constructed in the same principle. The present invention is obviously applicable to a system in which a single data processor initiates several tasks and separate addresses are assigned to the individual tasks for implementing parallel display processings. The memory circuit of the above embodiment differs from the usual memory IC component in that the set signal FS for setting the operational function and w-rite-mask data and the signal C for selecting an operational function and write mask are involved. These signals may be provided from outside at the expense of two additional IC pins as compared with the usual memory device, or may be substituted by the aforementioned signals by utilization of the memory access timing relationship for the purpose of minimizing the package size. FIG. 38 shows the memory access timing relation-ship for the latter method, in which a timing unused in the operation of a usual dynamic RAM is used to distinguish processors (the falling edge of RAS causes the WE signal to go low) and to set the operation code and write mask data (the rising edge of RAS causes CAS and WE signals to go low), thereby producing the FS and C signals equivalently. Although in the above embodiment a 16-bit data word is sliced into 1-bit groups, these values can obviously be altered. Although in the above embodiment the operational function and write mask are specified concurrently, they may be specified separately.
[0162] It is obvious that the word length for operational function specification may be other than 4 bits. The above embodiment can also be applied to a memory with a serial output port by incorporating a shift register. According to the above embodiments, the coordinate calculation process in the display process is shared by a plurality of processors so that the calculation time is reduced, and the frame buffer memory operative in a read-modify-write mode can be shared among the processors without the need of arbitration control so that the number of memory accesses is reduced, whereby a high-speed graphic display system can be constructed. Moreover, the modification operation for the read-modify-write operation is specified independently of the word length of write data, and this realizes a memory circuit incorporating a circuit which implements the read-modify-write operation in arbitrary word lengths, whereby a frame buffer used in a high-speed graphic display system, for example, can be made compact. | A memory device which includes dynamic random access memories for effecting data read and write operations, first and second data terminals for receiving data, and a controller having a first data input connected to receive first data, a second data input connected to receive second data, a third data input connected to receive a function mode signal, and operation unit for executing operations between the first data and the second data. The operation unit includes a function setting unit for setting a function indicated by a function mode signal prior to receipt of the first data. The second data is read out of a selected part of the storage locations. The operation corresponding to the set function is executed for the first and second data. The operation result is written into the selected part of the storage locations during one memory cycle. | 6 |
This is a division of application Ser. No. 09/108,263 filed Jul. 1, 1998.
TECHNICAL FIELD
The present disclosure describes a special image obscurement device for a light source.
BACKGROUND
In live dramatic performances controlled lighting is often used to illuminate a performer or other item of interest. The illuminated area for live dramatic performance is conventionally a circular beam of light called a “spot light.” This spot light has been formed from a bulb reflected by a spherical, parabolic, or ellipsoidal reflector. The combination forms a round beam due to the circular nature of reflectors and lenses.
The beam is often shaped by gobos. FIG. 1 shows a light source 100 projecting light through a triangular gobo 108 to the target 105 . The metal gobo 108 as shown is a sheet of material with an aperture 110 in the shape of the desired illumination. Here, that aperture 110 is triangular, but more generally it could be any shape. The gobo 108 restricts the amount of light which passes from the light source 100 to the imaging lenses 103 . As a result, the pattern of light 106 imaged on the stage 105 conforms to the shape of the aperture 110 in the gobo 108 .
Light and Sound Design, the assignee of this application, have pioneered an alternate approach of forming the gobo from multiple selected reflective silicon micromirrors 200 . One such array is called a digital mirror device (“DMD”) where individual mirrors are controlled by digital signals. See U.S. Pat. No. 5,828,485 the disclosure of which are herein incorporated by reference. DMDs have typically been used for projecting images from video sources. Because video images are typically rectangular, the mirrors of DMDs are arranged in a rectangular array of rows and columns.
The individual mirrors 200 of a DMD are rotatable. Each mirror 200 is mounted on a bar 204 such that it can rotate in place around the axis formed by the bar 204 . Using this rotation, individual mirrors 200 can be turned “on” and “off” to restrict the available reflective surface.
FIG. 2 shows an example of using a DMD 400 to project a triangular illumination by turning “off” some of the mirrors in the DMD 400 . The surface of the DMD 400 exposed to a light source 402 comprises three portions. The individual mirrors which are turned “on” (toward the light source 402 ) make up an active portion 404 . In FIG. 4A, the active portion 404 is triangular. The individual mirrors which are turned “off” (away from the light source 402 ) make up an inactive portion 406 . These pixels are reflected. The third portion is a surrounding edge 408 of the DMD 400 . Each of these portions of the DMD 400 reflects light from the light source 402 to different degrees.
FIG. 3 shows a resulting illumination pattern 410 with the active area 404 inactive area 406 and cage 408 .
SUMMARY
The inventors recognize that light reflected from the inactive portion 406 of the DMD 400 generates a dim rectangular penumbra 418 area is surrounding the bright desired area 404 . Light reflected from the edge 408 of the DMD 400 generates a dim frame area. The inventors recognized that this rectangular penumbra 418 is not desirable.
The inventors also recognized that a circular penumbra is much less noticeable in the context of illumination used in dramatic lighting.
Accordingly the inventors have determined that it would be desirable to have a device which would provide a circular illumination without a rectangular penumbra while using a rectangular arrayed device as an imaging surface. The present disclosure provides such capabilities.
This disclosure describes controlling illumination from a light source. The disclosed system is optimized for use with a rectangular, arrayed, selective imaging device.
In a preferred embodiment, a rotatable shutter with three positions is placed between a DMD and the imaging optical system. The first position of the shutter is a mask, preferably a circle, placed at a point in the optical system to be slightly out of focus. This circle creates a circular mask and changes any unwanted dim reflection to a circular shape. The second position of the shutter is completely open, allowing substantially all the light to pass. The third position of the shutter is completely closed, blocking substantially all the light from passing.
An alternate embodiment for blocking the rectangular penumbra by changing any penumbra to round uses an iris shutter placed between a DMD and increases optics. The iris shutter creates a variable aperture which ranges from completely closed to completely open. Intermediate settings include circles of varying diameter, resulting in similar projections as with the first position of the shutter embodiment.
Another alternate embodiment for blocking the rectangular penumbra by changing any penumbra to round uses two reflective surfaces. The first reflective surface is a DMD. The second reflective surface is preferably a light-sensitive reflective surface such as a polymer. If the light striking a portion of the reflective surface is not sufficiently bright, that portion will not reflect the full amount of that light.
By controlling the penumbra illumination surrounding the desired illumination, DMDs and other pixel-based rectangular elements can be used in illumination devices without creating undesirable rectangular penumbras.
DESCRIPTION OF DRAWINGS
FIG. 1 shows a conventional illumination device including a gobo.
FIG. 2 shows an illumination device including a DMD.
FIGS. 3A-3G shows a illumination patterns.
FIG. 4 show the optical train.
FIG. 5 shows a three position shutter according to a preferred embodiment of the present invention.
FIG. 6A shows an illumination device including a three position shutter according to a preferred embodiment of the present invention which is set to a mask position.
FIG. 6B shows an illumination pattern resulting from the device shown in FIG. 6 A.
FIG. 7 shows an iris-type shutter.
FIGS. 8A and 8B show use of the adjustable iris in a DMD system.
FIG. 9 shows a three-position shutter with an iris system.
FIG. 10 shows an embodiment with a light.
DETAILED DESCRIPTION
The structure and operational parameters of preferred embodiments will be explained below making reference to the drawings.
The present system uses two different operations to minimize the viewable effect of the unintentional illumination, or penumbra, discussed previously. A first operation forms the optics of the system in a way which prevents certain light from being focused on the DMD and hence prevents that light from being reflected. By appropriately masking the incoming light to the DMD, certain edge portions of the penumbra can be masked. A second part of the system uses a special illumination shutter to provide different shaped penumbras when desired.
The overall optical system is shown in FIG. 4 . The bulb assembly 200 includes a high wattage bulb, here an MSR 1200 SA Xenon bulb 202 and retroreflectors 204 which capture some of the output from that bulb. The output of the bulb is coupled to a dichroic or “cold” mirror 206 which reflects the visible light while passing certain portions of the infrared. The first focus of the reflector is at Point 208 . A DMD mask is located at that point. The DMD mask is preferably rectangular, and substantially precisely the shape of the inner area 418 of the DMD. The image of the mask is also focused onto the DMD: such that if one were looking at the mask from the position of the DMD, one would see the mask clearly and in focus.
A first color system includes an RGB system 210 and a parametric color system 212 . The light passes through all of these elements and is then further processed by an illumination relay lens 214 and then by an imaging relay lens 216 . The image relay lens 216 has an aperture of 35 millimeters by 48 millimeters. The output is focused through a field lens 216 to the DMD 400 . The off pixels are coupled to heat sink 220 , and the on pixels are coupled via path 222 back through the imaging relay 216 folded in the further optics 224 and finally coupled to zoom elements 230 . The zoom elements control the amount of zoom of the light beam. The light is colored by a designer color wheel 232 and finally focused by a final focus element 235 .
The way in which the outer penumbra is removed will be explained with reference to FIGS. 3A and 4B.
FIG. 3B shows the front surface of the DMD. This includes a relatively small inner active portion 350 which includes the movable mirrors. Active portion 350 is surrounded by a white inactive portion 352 which is surrounded by packaging portion 354 , a gold package 356 , and a ceramic package 358 . Light is input at a 20° angle from the perpendicular. The reason why becomes apparent when one considers FIG. 3 C. The mirrors in the DMD tip by 10°.
FIG. 3C shows two exemplary mirrors, one mirror 360 being on, and the other mirror 362 being off. Input light 362 is input at a 20° angle. Hence, light from the on mirror emerges from the DMD perpendicular to its front surface shown as 364 . However, the same light 362 impinging on an off mirror emerges at a different angle shown as 366 . The difference between those two angles forms the difference between undesired light and desired light. However, note in FIG. 3C what happens when the incoming light 362 hits a flat surface. Note the outgoing beam 368 is at a different angle than either the off position or the on position. The hypothetical beam 366 from an off mirror is also shown.
The inventors recognize, therefore, that a lot of this information falls within an undesired cone of light. All light which is input (e.g. 362 rays can be filtered by removing the undesired cone. This is done according to the present disclosure by stopping down the cone of light to about 18° on each side. The final result is shown in FIG. 3 D. The incoming light is stopped down to a cone of 18° by an F13.2 lens. The incoming light is coupled to the surface of the DMD 400 , and the outgoing light is also stopped to a cone of 18°. These cones in the optical systems are identified such that the exit cone does not overlap with the undesired cone 367 shown in FIG. 3 C.
This operation is made possible by appropriate two-dimensional selection of the incoming light to the digital mirror. FIG. 3E shows the active portion 350 of the digital mirror. Each pixel is a rectangular mirror 370 , hinged on axis 372 . In order to allow use of this mirror and its hinge, the light needs to be input at a 45° angle to the mirror, shown as incident light ray 374 . The inventors recognized, however, that light can be anywhere on the plane defined by the line 374 and perpendicular to the plane of the paper in FIG. 3 E. Hence, the light of this embodiment is input at the 45° angle shown in FIG. 3 E and also at a 20° angle shown in FIG. 3F which represents a cross section along the line 3 F— 3 F. This complex angle enables using a plane of light which has no interference from the undesired portions of the light. Hence, by using the specific desired lenses, reflections of random scattered illumination is bouncing off the other parts is removed. This masking carried out by at least one of the DMD mask 208 and the DMD lens 216 . By appropriate selection of the input light, the output light has a profile as shown in FIG. 3G. 350 represents the DMD active area, 356 represents the border, and 358 represents the mount. The light output is only from the DMD active area and is stopped and focused by appropriate lenses as shown in FIG. 3 G.
FIG. 5 shows a planar view of a shutter 500 according to a preferred embodiment of the invention. The preferred configuration of the shutter 500 is a disk divided into three sections. Each section represents one position to which the shutter 500 may be set. The shutter 500 is preferably rotated about the center point 502 of the shutter. The gate of the light is off center, to allow it to interact with one of the three sections. Rotation is preferred because rotation allows efficient transition between positions. Alternately, the shutter 500 may slide vertically or horizontally to change from one position to another. A round shape is preferred because of efficiency in material and space use. Alternately, the shutter 500 may be rectangular or some other polygonal shape.
Three positions are preferred because each position is rotatably equidistant from the other positions. However, a shutter 500 with three positions provides more positions than a shutter 500 with only two positions.
In a preferred embodiment, a first position is a mask position 504 . The mask position 504 includes an open or transparent aperture 506 and an opaque mask portion 508 which is not permeable to light. Preferably, material is removed from the shutter 500 leaving a shaped aperture 506 and a mask portion 508 .
The second position is an open position 510 . The open position 510 includes an opening 512 . Preferably the opening 512 is formed by removing substantially all material from the shutter 500 in the section of the open position 510 .
The third position is a closed position 514 . The closed position 514 includes a opaque barrier portion 516 . Preferably, the barrier portion 516 is just a solid block of material.
FIG. 6A shows a preferred embodiment of an illumination system. A shutter 500 of the type shown in FIG. 5 is rotatably mounted between a light source 602 /DMD 604 such that substantially all the light from the light source 602 strikes only one section of the shutter 500 at a time. The shutter 500 is rotatably positioned to the mask position 504 . Thus, when the light source 602 is activated, light from the light source 602 reflected by DMD 604 strikes only the mask position 504 of the shutter 500 .
Using digital control signals, the DMD 604 is set so that an active portion 612 of the individual mirrors are turned “on” and an inactive portion 614 of the individual mirrors are turned “off” (see FIG. 4 A). The shape of the active portion 612 is set to conform to the desired shape of the bright portion of the illumination reflected by the DMD 604 shown in FIG. 6B, described below.
FIG. 6B shows an illumination pattern 620 generated by the illumination device 600 configured as shown in FIG. 6 A.
Returning to FIGS. 4A and 4B, when the shutter 500 is not interposed between the DMD 400 and the stage. All portions of the DMD 400 reflect the light and create the undesirable illumination pattern 410 shown in FIG. 4 B. In particular, the bright circular area 414 is surrounded by an undesirable dim rectangular penumbra 418 and slightly brighter frame 422 .
As described above, the illumination pattern 614 shown in FIG. 6B does not include a dim rectangular penumbra 418 and a slightly brighter frame 422 . These undesirable projections are substantially eliminated by using the shutter 500 and the aperture 506 . A dim penumbra illumination 628 is generated by light reflecting from the inactive portion 614 of the DMD 604 . This dim circular penumbra illumination 628 is more desirable than the dim rectangular penumbra 418 and slightly brighter frame 422 of FIG. 4B because the shape of the dim penumbra illumination 628 is controlled by the shape of the aperture 506 . Accordingly, the dim penumbra illumination 628 can be conformed to a desirable shape.
FIG. 7 shows an alternate embodiment for an iris shutter 900 . Preferably, a series of opaque plates 902 are arranged inside a ring 904 to form an iris diaphragm. By turning the ring 904 the plates 902 move so that an iris aperture 906 in the center of the iris shutter 900 varies in diameter. The iris aperture 906 preferably varies from closed to a desired maximum open diameter. Preferably the iris shutter 900 can transition from closed to a maximum diameter (or the reverse) in 0.1 seconds or less.
FIG. 10A shows an illumination device 1000 including an iris shutter 900 as shown in FIG. 9 . The iris shutter 900 is positioned between a DMD 1002 and a stage 1004 . In FIG. 10A, the iris shutter 900 is partially open such that the iris aperture 906 allows part of the light 1006 , 1008 from the light source 1002 to pass through, similar to the mask position 504 of the three position shutter 500 shown in FIG. 6 A. One difference between the mask position 504 and the iris shutter 900 is that the iris aperture 906 is variable in diameter while the aperture 506 of the mask position 504 is fixed. The remainder of the light 1010 from the light source 1002 is blocked by the plates 902 of the iris shutter 900 . The light 1006 , 1008 which passes through the iris aperture 906 strikes the DMD 1004 in a pattern 1012 which is the same shape as the shape of the iris aperture 906 . Through digital control signals, some of the individual mirrors of the DMD 1004 are turned “on” to form an active portion 1014 , and some of the individual mirrors are turned “off” to form an inactive region 1016 . Preferably, the pattern 1012 is at least as large as the active portion 1014 of the DMD.
FIG. 10B shows an illumination pattern 1018 generated by the illumination device 1000 shown in FIG. 10 A. Similar to FIGS. 6A and 6B, a bright illumination 1020 is generated by light 1022 reflected from the active portion 1014 of the DMD 1004 . A dim penumbra illumination 1024 is generated by light 1026 reflected from the inactive portion 1016 of the DMD 1004 . By varying the diameter of the iris aperture 906 , the size of the pattern 1012 on the DMD 1004 changes. As the pattern 1012 changes the amount of the inactive portion 1016 of the DMD 1004 which is struck by light 1008 from the light source 1002 changes and so the dim penumbra 1024 changes as well.
FIG. 9 shows an alternate embodiment of a shutter 1100 which combines features of a three position shutter 500 with an iris shutter 900 . The overall configuration of this shutter 1100 is that of the three position shutter 500 . However, instead of the mask portion 504 as shown in FIG. 5 and FIG. 6A, one of the positions is an iris portion 1102 . The iris portion 1102 has an iris diaphragm 1104 inserted into the material of the shutter 1100 . Similar to the iris shutter 900 of FIG. 9, the iris diaphragm 1104 is made from a series of opaque plates 1106 arranged inside a ring 1108 . By turning the ring 1108 the plates 1106 move so that an iris aperture 1110 in the center of the iris diaphragm 1104 varies in diameter. This configuration operates in most respects similarly to the three position shutter 500 as shown in FIG. 5 and FIG. 6 A. Because of the iris diaphragm 1104 , the amount of light blocked by the iris portion 1102 is variable.
FIG. 12A shows an alternate embodiment of an illumination device 1200 which includes a second reflective surface 1202 . A light source 1204 projects light onto a DMD 1206 which has an active portion 1208 and an inactive portion 1210 . Light reflects off the DMD 1206 and strikes the second reflective surface 1202 . The second reflective surface 1202 acts to reduce the dim penumbra and frame created by the inactive portion 1210 and edge 1212 of the DMD 1206 (recall FIGS. 4 A and 4 B).
In the embodiment shown in FIG. 12A, the second reflective surface 1202 is a light sensitive surface such as an array of light trigger cells. Only light of a certain brightness is reflected. If the light striking a cell is insufficiently bright, substantially no light is reflected by that cell. Alternately, the second reflective surface 1202 may be made of a polymer material that only reflects or passes light of sufficient brightness. Light 1214 reflected from the active portion 1208 of the DMD 1206 is preferably bright enough to be reflected from the second reflective surface 1202 . Light 1216 , 1218 reflected from the inactive portion 1210 and the edge 1212 of the DMD 1206 is preferably not bright enough to be reflected from the second reflective surface 1202 . Thus, only light 1214 from the active portion 1208 of the DMD 1206 will be reflected from the second reflective surface 1202 . As described above, the undesirable dim rectangular penumbra 418 and slightly brighter frame 422 (recall FIG. 4B) would be created by light 1216 , 1218 reflected from the inactive portion 1210 and edge 1212 of the DMD 1206 . The second reflective surface 1202 does not reflect this dim light 1216 , 1218 and so wholly eliminates the dim penumbra and frame from the resulting illumination.
A number of embodiments of the present invention have been described which provide controlled obscurement of illumination. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, filters or lenses might be introduced to the illumination device 600 shown in FIG. 6A between the shutter 500 and the DMD 604 . Alternately, the light source might be a video projection device or a laser.
While this disclosure describes blocking the light before impinging on the DMD, it should be understood that this same device could be used anywhere in the optical train, including downstream of the DMD. Preferably the blocking is at an out of focus location to soften the edge of the penumbra, but could be in-focus.
The light reflecting device could be any such device, including a DMD, a grating light valve (“GLV”), or any other arrayed reflecting device which has a non-circular shape.
All such modifications are intended to be encompassed in the following claims. | An illumination obscurement device for controlling the obscurement of illumination from a light source which is optimized for use with a rectangular, arrayed, selective reflection device. In a preferred embodiment, a rotatable shutter with three positions is placed between a light source and a DMD. The first position of the shutter is a mask, preferably an out of focus circle. This out of focus circle creates a circular mask and changes any unwanted dim reflection to a circular shape. The second position of the shutter is completely open, allowing substantially all the light to pass. The third position of the shutter is completely closed, blocking substantially all the light from passing. By controlling the penumbra illumination surrounding the desired illumination, DMDs can be used in illumination devices without creating undesirable rectangular penumbras. | 8 |
FIELD OF THE INVENTION
This invention relates to a safety monitoring circuit, and, more particularly, relates to a circuit for monitoring the current in the return path of an electrosurgical unit.
BACKGROUND OF THE INVENTION
Electrosurgery has found widespread use in the medical field to perform cutting and coagulating operations. Normally, the patient is placed in contact with a patient electrode or plate connected to the patient terminal of a radio frequency (RF) source. The active terminal of the RF source is then connected to the active electrode of an electrosurgical instrument which is commonly utilized as a cutting or coagulating electrode when brought into patient contact. When so utilized, the RF source applies a high density current to the active electrode at a relatively high voltage and this causes a localized cutting or coagulating action. The current, after flowing through the active electrode, is normally returned through the patient plate to the RF source. To insure a low current density other than at the active electrode, the patient plate is designed to contact the patient over a relatively large area. This results in the needed low current density and thus prevents the occurrence of localized electrical burns as long as the patient plate contacts the patient over the large area.
If the return path connecting the patient plate to the RF source is broken, however, or if the patient should move out of contact with a large area of the patient plate, it has been found that electrical burns can result since there is no longer a low current density connection for return of the RF energy. Such a burn could occur, for example, where there is a secondary return contact to the patient since current can flow through the secondary return contact and thus cause localized burning of the patient at the point where the secondary return contacts the patient.
Such secondary return contacts could exist, for example, where monitoring electrodes are connected to the patient, where there is grounded adjacent metallic equipment, or where vertical supports are utilized for supporting ancillary equipment such as overhead lights. Since such secondary contacts with the patient are commonly in localized areas, the current density at these areas can be high and hence result in electrosurgical burns at these contact points.
Electrosurgical burns as described hereinabove can be quite severe since the patient is often unconscious during surgery and hence the existence of a condition causing such a burn could go unnoticed for a considerable length of time.
One method for minimizing the burn hazard that has been suggested is to provide an isolated output. It has been found, however, that the safety of such a circuit is limited by RF leakage currents, which depend upon output-to-ground capacitances and the RF waveform. When these factors preclude the use of an isolated output, an internal ground applied to the patient terminal becomes necessary.
While safety circuits have been suggested and/or utilized heretofore in an attempt to prevent such a condition or to at least minimize burns where such a condition comes into existence, it has been found that advantages can be obtained by utilizing a safety circuit with components different from those heretofore suggested and/or utilized. An electrosurgical safety circuit is shown, for example, in U.S. Pat. No. 3,683,923 issued Aug. 15, 1972, to Robert K. Anderson and assigned to the assignee of the present invention.
SUMMARY OF THE INVENTION
This invention provides an improved safety monitoring circuit that is particularly useful in an electrosurgical unit to sense the current flow in the return path and responsive thereto indicating a fault due to improper patient contact with the patient electrode or a disruption in the normal return path. The safety monitoring circuit of this invention is capable of preventing large current flow through an internal ground under a fault condition where such a ground is needed as brought out hereinabove. The described embodiment of the invention includes a current sensor the output from which is coupled to a comparator which provides an output when a predetermined threshold is exceeded with the output from the comparator triggering a timer that energizes, for a predetermined period of time, an alarm and/or disables the RF current flow in the utilization means.
It is, therefore, an object of this invention to provide a new and novel safety monitoring circuit.
It is another object of this invention to provide a new and novel safety monitoring circuit that is useful in an electrosurgical unit to prevent patient burns.
It is still another object of this invention to provide a new and novel safety monitoring circuit that is accurate and quite reliable.
It is another object of this invention to provide a new and novel safety monitoring circuit that actuates an alarm for a predetermined period of time if a ground fault is sensed.
It is still another object of this invention to provide a new and novel safety monitoring circuit for an electrosurgical unit that automatically disrupts, for a predetermined period of time, the application of power to an active electrode in contact with a patient upon sensing of a return fault.
It is yet another object of this invention to provide a new and novel safety monitoring circuit that includes a current sensor, a comparator, and a timer which are utilized in combination to actuate fault indicating means when current sensed in a return path exceeds a predetermined level.
With these and other objects in view, which will become apparent to one skilled in the art as the description proceeds, this invention resides in the novel construction, combination, and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the herein disclosed invention are meant to be included as come within the scope of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate a complete embodiment of the invention according to the best mode so far devised for the practical application of the principles thereof, and in which:
FIG. 1 is a diagram, partially in pictorial, block and schematic form, illustrating the safety monitoring circuit of this invention incorporated into an electrosurgical unit; and
FIG. 2 is an electrical schematic diagram of a portion of the safety monitoring device shown in block form in FIG. 1.
DESCRIPTION OF THE INVENTION
Referring to the drawings, the numeral 7 indicates generally the safety monitoring circuit of this invention and is shown incorporated into an electrosurgical unit 9. Electrosurgical units of the type illustrated are well known and accordingly only those portions of the unit necessary for an understanding of the safety monitoring circuit of this invention are described herein.
As shown in FIG. 1, secondary winding 11 of the output transformer of an RF source (not shown) is connected at the active side through active path, or conductor, 12 to an electrosurgical instrument, or active electrode, 13. As is well known, such an electrosurgical instrument is commonly utilized for either cutting or coagulating (or a combination of both) and is brought into contact with a patient 15 at the point where an operation is to be performed. As also indicated in FIG. 1, the patient is preferably placed into contact with a relatively large patient electrode or plate, 17 which is connected to the return conductor 18, which conductor provides a return path to the patient terminal of secondary winding 11.
As also indicated in FIG. 1, switches 20 and 21, activated by a relay 22, can be provided in the line to disrupt application of RF power from an RF source to the electrosurgical instrument contactable with the patient and with the return path from the patient electrode to such an RF source. A secondary or parallel return path has been indicated in FIG. 1 by means of lead 24 and resistor 25. As brought out hereinabove, such a path could be established in several diverse manners.
As also shown in FIG. 1, current flow through the secondary return path 24 and resistor 25 is returned to secondary winding 11 through current sensor 27 and capacitor 29 connected in series with one another. In the prior art, the secondary return through path 24 and resistor 25 was commonly directly through ground back to secondary winding 11.
Current sensor 27 is preferably an RF thermocouple which is a device that is inherently sensitive to rms current, and is thus desirable for electrosurgical use where threshold current is preferably not dependent upon the mode of operation (i.e., cut, coagulation, or a combination of both).
Capacitor 29 is optional and provides an impedance which has a low value at RF frequencies and a high value at low frequencies so that the 60 Hz line frequency sink capability of the electrosurgical unit will not be dangerous. Capacitor 29 may be, for example, a single capacitor having a high value such that its impedance at the frequencies where RF current will be conducted will be low so that the voltages across the ground line will be sufficiently low to prevent a hazard to the patient. Such a capacitor may be, for example, of a value of 2000 pf.
As also shown in FIG. 1, the output from current sensor 27 is coupled through DC amplifier, or signal conditioning means, 31 to comparator, or interface means, 33. The output from comparator 33 is coupled to triggered timer 35, the output from which is utilized to energize alarm 37 and/or relay 22. The energization of relay 22, of course, causes switches 20 and 21 to be opened and thus terminates the application of RF energy to a patient. The switching arrangement provided by relay 22 and switches 20-21 could, of course, be provided by other arrangements, such as, for example, by supplying a control signal to the RF source circuitry (not shown) to effect a decrease of the output level of the RF source. When utilizing such an arrangement, an output from interface means 33 could be coupled to an RF generator driving transformer winding (not shown) at the RF source to be controlled.
The use of a current sensor placed in series with the ground line allows use of circuitry including a comparator to establish a threshold such that current above a certain value will trigger the alarm and/or disabling circuit, while permitting currents below the threshold level to pass without energizing the alarm and/or disabling circuit. In addition, by providing a variable reference voltage to the comparator, the threshold can, of course, be adjusted as desired. When the sensed current from the current sensor exceeds the comparison reference voltage, an output is provided to timer 35 to energize the alarm 37 and/or disabling circuit. Timer 35 is utilized so that the alarm and/or disabling circuit can be energized for only a predetermined amount of time so that reset action is unnecessary in that the apparatus will automatically reset at the end of the timed period.
FIG. 2 illustrates, in electrical schematic form, DC amplifier 31, comparator 33, triggered timer 35, and alarm 37, along with associated circuitry. While not shown, a shield can be provided for amplifier 31 and comparator 33. As shown, the input from the RF thermocouple (current sensor) 27 is coupled to the positive (+) input (pin 5) of DC amplifier 31 through series connected resistors 39 and 40 with resistor 39 being connected at one side to resistor 41 and at the other side to ground through capacitor 43 with the other side of resistor 40 being connected to ground through capacitor 44.
The other side of thermocouple 27 is connected to the negative (-) input (pin 4) of DC amplifier 31 through series connected resistors 46 and 47 with resistor 46 being connected at one side to resistor 41 and at the other side with ground through capacitor 49, while resistor 47 is connected at the other side with ground through capacitor 50. In addition, pins 4 and 10 of DC amplifier 31 are connected through resistor 51, and pin 11 is connected to a +20 volt power supply through resistor 53 which resistor has capacitor 54 connected with ground at the pin 11 side thereof. Pin 6 of DC amplifier 31 is connected to a -v supply through resistor 56 which resistor has capacitor 57 connected with ground at the pin 6 side thereof.
The output from DC amplifier 31 is coupled from pin 10 through resistor 59 to the negative (-) input side (pin 2) of comparator 33. Comparator 33 has a resistor 60 connected between pins 2 and 6, with pin 3 being connected through resistor 62 to the center tap of potentiometer 63. Potentiometer 63 is connected in series with resistor 65 to define a voltage divider between the +20 volt power supply and ground. The junction of potentiometer 63 and resistor 65 has a by pass capacitor 66 to ground, while the pin 3 side of resistor 62 has a by pass capacitor 67 to ground. Pin 7 of comparator 33 is connected with the +20 volt power supply through resistor 69 and with ground through by pass capacitor 70. Pin 4 of comparator 33 is connected with the -v supply through resistor 72 and with ground through by pass capacitor 73.
The output from comparator 33 is taken from pin 6 and coupled through series connected resistors 75 and 76 to pin 2 of triggered timer 35, with the junction between resistors 75 and 76 having a by pass capacitor 77 to ground. Power is supplied to timer 35 through series connected resistor 79 and Zener diode 80 with resistor 81 being connected to the junction of resistor 79 and pins 4 and 8 of the timer. In addition, capacitor 82 is connected between ground and pins 4 and 8 of the timer, while pin 5 is connected with ground through capacitor 83, and pin 7 is connected with ground through capacitor 84.
The output from triggered timer 35 is taken through resistor 86 to the base of transistor 87, the emitter of which is connected with ground while the collector is connected through resistor 89 to indicator 37, which indicator, in turn, is connected to a +60 volt power supply. The parallel output from timer 35 is taken through resistor 90 and coupled to relay 22.
Particular components which have been utilized in a working embodiment of this invention are as follows, it being realized that the particular components specified are for illustration only and that the invention is not meant to be limited thereto:
DC amplifier 31--LM207
Comparator 33--741
Timer 35--NE555
Zener diode 80--5.6 V
Transistor 87--2N3568
Resistors (ohms): 39, 40, 46 and 47--510 ohms; 41--10 ohms; 51--510K; 53, 56, 69, 72 and 79--51 ohms; 59 and 62--5.6K; 60--5.6M; 65--20K; 75 and 76--1K; 81--1.8M; 86 and 90--2.2K; and 89--100 ohms
Potentiometer 63--0 to 20 Kohms
Capacitors: 29--2000 pf; 43, 44, 49, 50, 54, 57, 67, 70, 73, 77, 82 and 83--0.01 μfd; 66 and 84--1 μfd.
In operation, the safety monitoring circuit of this invention, when used with an electrosurgical unit, senses current flow in the return path and so long as the current flow remains below a predetermined level, as determined by the reference voltage at the comparator 33, the electrosurgical unit operates normally and the circuit continues to monitor current flow without affecting operation of the electrosurgical unit. If the flow exceeds a predetermined maximum level, then comparator 33 provides an output which triggers the triggered timer 35 and the output from the timer 35 energizes an alarm 37 which is shown as a light but could be an audible alarm, if desired. In addition, the output from triggered timer 35 can also be utilized to terminate the application of RF energy to the electrosurgical instrument contactable with a patient. As indicated, this can be accomplished by utilizing a relay 22, for example, to open switches 20 and 21. At the end of the timed period, as determined by timer 35, the alarm 37 is deenergized and the circuit automatically reactivated to apply again RF energy to the electrosurgical instrument. This precludes the necessity of resetting by the operator and, of course, if the fault has not been corrected, the alarm 37 will again be energized and application of power again discontinued if disabling circuitry is utilized. After the fault has been corrected, the automatic reset occurring at the end of the timed period will cause normal operation of the electrosurgical unit to be resumed. | A safety monitoring circuit for use in an electrosurgical unit is disclosed. The circuit is useful to indicate a fault in the return path between an RF source and a patient electrode in contact with a patient to prevent electrical burns to the patient that can occur due to improper patient contact with the patient electrode or a break in the return path. The circuit includes a current sensor connected in series in the return path to the RF source, which sensor provides an output indicative of the sensed current that is coupled through a DC amplifier to a comparator, the comparator providing an output only if a predetermined threshold is exceeded. When a comparator output is provided, a timer is triggered to energize, for a predetermined period of time, an alarm to indicate a sensed fault and/or actuate disabling circuitry to terminate application of electrical energy to the active electrode utilized in electrosurgery for cutting or coagulation. | 0 |
REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 13/694,804, filed Jan. 9, 2013 (hereinafter “the '804 Application”), which is hereby incorporated herein by reference, and which claims the benefit of U.S. provisional patent application Ser. No. 61/631,702, filed Jan. 10, 2012. The '804 Application is a continuation-in-part of U.S. patent application Ser. No. 12/927,030, filed Nov. 5, 2010, which claimed the benefit of U.S. provisional patent application Ser. No. 61/280,244, filed Nov. 2, 2009, and the '804 Application is also a continuation-in-part of U.S. patent application Ser. No. 12/322,625, filed Feb. 4, 2009, which claimed the benefit of U.S. provisional patent application Ser. No. 61/065,284, filed Feb. 11 2008, which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the field of mobile geolocation and mobile based applications. It pertains specifically to a system and method for determining audience characteristics of a music concert based on the analysis of mobile phone tracking and mobile data transmissions. In the preferred embodiment, the system tracks, and analyzes mobile data, activity and transmissions, providing audience characteristics of a music concert, including, but not limited to demographics, sentiment, engagement, popularity and segmentation.
2. Description of Related Art
The conventional means of determining the audience size at a music concert, apart from counting people who attend, is to count the number of tickets sold. Information on ticket sales is sometimes available from ticket sales service providers such as TicketMaster. Yet counting tickets can be impractical. Some venues, particularly smaller ones, may not use an accessible ticket sales service like TicketMaster, or may not sell tickets at all. Even if ticket sales were accessible, audience size may not reflect ticket sales if some ticket holders do not attend or some tickets are given away and not accounted for in sales. Moreover, tickets sales alone provide little or no information about the concert, for example, an audience's sentiment about the concert.
Meanwhile, mobile phone use has become nearly ubiquitous. By the end of 2008, for example, there were more than 270 million cell phone subscriptions in the United States, which represents about 87% of the total U.S. population, according to the International Association for the Wireless Telecommunications Industry. With the improvement of mobile phone tracking technology and the increasing incorporation of global positioning system (GPS) technology into mobile phones, the field of mobile data analytics has emerged, which uses location information to understand the behavior of mobile phone users, often in real-time.
A number of research efforts and companies have been formed to exploit this new field. SenseNetworks, for example, is a pioneering company in the field of mobile data analytics. It tracks the location of mobile phone users in real-time, segments them into groups based on common behaviors and locations, and makes predictions about future behavior. One of its applications, called CitySense, tracks the overall activity of a city based on location data and indicates the “hotspots” of activity, such as nightclubs and other venues, wherein activity is defined essentially as the collective presence of active mobile phones at a location. The level of activity of a venue is gauged relative to its historical activity as well as the activity observed at other venues. However. while CitySense application tracks the number of mobile devices at a venue, it makes no determination of the size or sentiment of an audience attending a concert at a venue, the audience's perception of the performance of the concert, the anticipation of the concert, the audience's demographics, the audience's engagement with the artist(s) performing during the concert or other audience participant characteristics, etc.
There are a number of mobile applications that concert goers currently use on their mobile phones when attending concerts. For example, Facebook, for determining which of their friends is also at the concert; Foursquare, for checking into a concert venue to learn tips about the concert venue, or special offers from the concert venue; Flickr, for sharing pictures of the concert; YouTube, for sharing video clips of the concert; and, Twitter, for sharing thoughts about the concert, to name a few mobile applications. However, to date, none of these mobile applications are focused on understanding the audience size and sentiment by amalgamating, tracking and analyzing mobile phone data, activity and transmissions.
Further, all of the aforementioned mobile phone applications have Application Programming Interfaces (APIs), where certain data, if applicable, may be imported from the aforementioned sources, or other third party sources. For reference herein, APIs, are particular specifications that the Concert Profiling System will utilize, to access and make use of services, information, data and/or resources, etc., that are provided by a particular software program that implements the API.
What is lacking in the prior art is a means not only to observe the number of active mobile phones at a venue but also a means to determine the size and sentiment of an audience attending a concert at the venue where the mobile phone activity is observed.
SUMMARY
In view of the limitations now present in the prior art, the present invention provides a new and useful system and method for determining audience characteristics of a concert, such as the size and sentiment of an audience attending a concert at a venue where mobile phone activity is observed, the audience's perception of the performance of the concert, the anticipation of the concert, the audience's demographics, the audience's engagement with the artist(s) performing during the concert or other audience participant characteristics, etc. It is also a purpose of the present invention to provide a new system and method for determining the size, demographics, engagement and sentiment of an audience attending a concert at a venue based on mobile phone location tracking and audience feedback (e.g. comments, photos, video, etc.) which are sent via mobile devices, and thus, this invention has many novel features not offered by the prior art applications that result in a new system and method which is not apparent or obvious, either directly or indirectly by any of the prior art applications. This system is referred to herein as the Concert Profiling System (CPS).
The goal of present invention disclosed herein, is to determine the characteristics of an audience attending a concert, such as the size and sentiment of an audience attending a concert at a venue where mobile phone activity is observed, the audience's perception of the performance of the concert, the anticipation of the concert, the audience's demographics, the audience's engagement with the artist(s) performing during the concert or other audience participant characteristics, etc. In the preferred embodiment, a venue is any location hosting a music related performance such as a concert, ranging from a small night club or auditorium, to a large theater or coliseum. Venues may also include outdoor locations such as parks, fields and amphitheaters.
A network-based system utilizes signals from cell phones to derive their location, utilizing one or several signal towers (base stations) to take distance measurements. These measurements are then sent to a location center where the subscriber's position is calculated, such as by triangulation of the signals. There is no requirement to make any changes to the current handsets. However, the cell phone must be in active mode (i.e., in “talk” mode or sending a signal through the control channel) to enable location measurement. According to Openwave, Inc., the network-based system has an accuracy of 50 to 200 meters if the triangulation is employed and up to 300 meters for other methods.
A handset-based system, on the other hand, typically relies on GPS enabled mobile phones. The GPS unit in the handset determines the location of a mobile phone based on signals received from satellites, and this information is relayed from the mobile phone to a central processing system maintained by the mobile phone carrier. As GPS chips become a staple component of the mobile phone, this method is becoming the predominant one. According to Openwave, Inc., the handset-based system has an accuracy of 5 to 30 meters, depending on characteristics of the surrounding environment, and is typically less than 15 meters. This accuracy is expected to improve over time with technological advancements as well as the use of the network-based system in conjunction with GPS technology with.
Additionally, smartphones are experiencing accelerated rates of adoption, which means larger, and more complex data will be transmitted with greater frequency by larger numbers of users. According to Berg Insight, in March of 2011, smartphone shipments increased 74% from 2009 to 2010, and according to ComScore, over 45.5 million people in the United States owned smartphones in 2010. For reference herein, smartphones, such as the iPhone and Android offer advanced mobile computing capability, allowing end-users to install and run advanced applications and games.
Generally speaking, in the preferred embodiment, a location data provider will provide to the CPS at least the longitude and latitude coordinates, also known as a geolocation, for active mobile phones within a requested geographical area for a given time period. This data may be provided in near real-time, at a regular time interval, upon request by the CPS, or upon the trigger of an event or action. Such information may include the physical dimensions of a venue, the venue's seating and operating capacity, and its availability and hours of operation, which may also be obtained from companies like Songkick, Bandsintown, OnlineGigs and Ticketmaster, either directly, or through their API(s).
Still another means of determining geolocation in the preferred embodiment is to receive location information from players of Music Scout, a game and utility application. A Music Scout application operates on a player's mobile phone and determines the location of the mobile phone by accessing the mobile phone's GPS unit or by asking the player to provide the location such as selecting the present location from a list of locations.
Based in part on the location data received for a venue, the CPS calculates metrics such as the size of the audience in attendance at the venue for a concert (number of persons) and the ratio of attendance to capacity of the venue. In the preferred embodiment, it can also archive historical location data for a venue, showing traffic to and from the venue over a time period, and calculate metrics such as average persons in attendance and the ratio of current attendance to average attendance. These averages may be calculated for certain historical time periods or for past concerts.
In determining certain metrics such as audience size, it is typically necessary for the CPS to perform calculations based on more information than the location data. These calculations may involve using additional information provided by other applications and/or by entities such as mobile phone carriers, federal government agencies such as the Federal Communications Commission (FCC), and third party research firms. Such information may include the physical dimensions of a venue, the venue's seating and operating capacity, and its availability and hours of operation. It may also include mobile phone coverage and market penetration data.
The CPS may also calculate metrics pertaining to the sentiment of an audience about a concert from qualitative information it receives. In the preferred embodiment, the CPS may receive sentiment information from Music Scout. During a concert, players of Music Scout provide sentiment information using their mobile phones. A player can “rate” his experience at the concert and/or “rate” the performance of a music artist by via a Music Scout application running on the player's mobile phone. By way of example, a player could select a rating between 1 (poor) and 5 (great) to indicate his sentiment. The player's measure of sentiment is examined collectively with other players at the same concert and may be used to provide a measure of sentiment for the whole audience. In the preferred embodiment, the CPS may receive sentiment information from the Popularity Profiling System (PPS) server as discussed in U.S. patent application Ser. No. 12/322,625.
In the preferred embodiment, the CPS may receive and/or provide data, including, but not limited to, audience sentiment and size characteristics to the Wagering System, U.S. patent application Ser. No. 12/927,030.
In the preferred embodiment, the CPS may receive sentiment information from the Popularity Profiling System (PPS) server, which is described in U.S. patent application Ser. No. 12/322,625. The PPS server may process sentiment information in the form of people's comments on social networking sites such as Facebook, Twitter and Foursquare, and related web-based applications where the comments can be associated reliably with a concert at a venue. An example of associating comments with a concert is through the examination of metadata for pictures posted to social networking sites, such as Flickr, wherein people typically have the ability to post comments about a particular picture posted. Pictures are stored according to image file formats and several of these formats, including Exif (used by digital cameras), support the recording of time, date and geolocation information. Similarly, relevant location information may be obtained from social media applications such as Twitter, Facebook and Foursquare.
In the preferred embodiment, once the CPS has performed its calculations of size, sentiment and any other metrics, these metrics are made available to one or more applications (or otherwise placed in a database accessible by one or more applications). One application that may use these metrics is the PPS, wherein the metric(s) may be incorporated as part of an artist's popularity profile. Music Scout is another application that may use these metrics.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a diagram illustrating the server/client network relationship of the Concert Profiling System server, information server(s) and client(s).
FIG. 2 illustrates a typical process in the preferred embodiment of the Concert Profiling System for calculating the size of an audience of a concert at a venue.
FIG. 3 illustrates a typical process in the preferred embodiment of the Concert Profiling System for calculating the sentiment of an audience of a concert at a venue.
FIG. 4 illustrates the preferred embodiment of the system components of the Concert Profiling System server.
FIG. 5 illustrates how the Concert Profiling System determines approximate demographics based on the data it collects.
FIG. 6 illustrates how the system calculates engagement quantities and segments the fan engagement from the mobile data transmissions collected by the Concert Profiling System during a music concert.
DETAILED DESCRIPTION
Although the following detailed description contains many specifics for the purposes of illustration, anyone of ordinary skill in the art will appreciate that many variations and alterations to the following details are within the scope of the invention. Accordingly, the following embodiments of the invention are set forth without any loss of generality to, and without imposing limitations upon, the claimed invention.
FIG. 1 illustrates a computing environment in which preferred embodiments are implemented. The computing environment 100 includes the Concert Profiling System (CPS) Server 101 , at least one client computer 102 , and at least one information server 103 that communicate over the Internet 104 . An information server 103 represents any source of data provided by through a server, including location data from a service like AirSage, Inc. or Skyhook, Inc., or any other third party application. In the preferred embodiment, a Popularity Profiling System Server 105 , described in U.S. patent application Ser. No. 12/322,625, and/or a Wagering System Server 106 , described in U.S. patent application Ser. No. 12/927,030, communicates with the CPS Server 101 via the Internet. Each server shown in FIG. 1 is identified with a unique Internet Protocol (IP) address. A client computer 102 can be any computing device seeking services from the CPS including mobile computers such as laptop computers, tablets, and smartphones. Computer software operating within this environment 100 may employ software and methods of application, including various pieces of code, including, but not limited to, Ruby, Erlang, PHP, Peri, ASP, Java, Javascript, Flash, SOAP, DHTML, HTML, XML, JSON, RSS, VML, Ajax, JQuerry, Python, Cocoa and C/C++/C#.
All computing devices 101 , 102 , 103 , 105 and 106 communicate using a document transfer protocol such as Hypertext Transfer Protocol, or any other document transfer protocol known in the art, such as FTP, Gopher, WAIS, XMLP, etc. Typically, the client 102 includes a browser program, such as an HTML browser, capable of submitting requests using the HTTP protocol in a manner known in the art. The client 102 may also be an application other than a browser, such as a rich internet application, capable of exchanging data and interfacing with a user.
FIG. 2 illustrates a typical process for calculating the size of an audience of a concert at a venue in the preferred embodiment of the CPS 200 which operates on the CPS Server 101 . At step 201 , mobile phone location data is received from a data provider. The data associated with each mobile phone being tracked is comprised typically of a unique identification number, location coordinates, and an operation timestamp.
The data is examined by the CPS 200 at step 202 to count the number of unique mobile phones whose geolocation coordinates are contained within the longitudinal and latitudinal boundaries of a venue being monitored by the CPS 200 , such as a venue associated with a concert occurring at the same time as the timestamp indicated by the location data. The count will at least represent the number of mobile phones within the venue boundary at a particular time. The CPS 200 may also count the cumulative number of mobile phones that have entered the venue boundary over a period of time. These counts may be different if the attendance at a venue exhibits churn.
Alternatively, in step 202 , a location will be considered to be contained within a venue boundary if it resides within a predefined margin outside the boundary. This margin of error may correspond to the limitations on the accuracy of location measurements performed by the carriers. If the data is received from Music Scout and the venue has been verified by the player, then the mobile phone is counted along with those within the venue boundary.
A venue location may be defined as a pair of longitudinal and a latitudinal coordinates, herein referred to as a center point. A venue boundary may be defined as a series of vertices of longitudinal and latitudinal coordinates that would form a perimeter around the center point if edges connected them together. In the preferred embodiment, a venue boundary is defined either (1) as a rectangle wherein a first vertex corresponds to the northernmost direction, a second vertex corresponds to the easternmost direction, a third vertex corresponds to the southernmost direction, and a fourth vertex corresponds to the westernmost direction; or (2) as a rectangle wherein a first vertex corresponds approximately to the northwest direction, a second vertex corresponds approximately to the northeast direction, a third vertex corresponds approximately to the southeast direction, and a fourth vertex corresponds approximately to the southwest direction. All directions are provided relative to the center point. A venue boundary typically corresponds to the approximate footprint of the building or physical structure or property line of the venue.
In step 203 , unqualified mobile phones are “filtered out” or removed from the count by the CPS 200 . In the preferred embodiment, a mobile phone is considered unqualified if it is non-stationary or if it is associated with employees of the venue. A non-stationary mobile phone is one whose location falls within the venue boundary for a brief time period (i.e. less than five minutes) and then moves out of it. A typical non-stationary mobile phone represents a person who passes near or through a venue on his way to another location outside of the venue boundary. Due to the margin of error in the accuracy of location measurements, some persons passing near a venue, such as walking on a sidewalk in front of a night club, may be included in the count of mobile phones considered to be within the venue boundary. Or some persons may pass through a venue, such as an outdoor plaza, on their way to another establishment, with no intention of staying at the plaza. A mobile phone may initially be considered to be qualified if its location falls within the venue boundary. But if subsequent tracking of the same mobile phone shows that the mobile phone has exited the venue boundary before a brief threshold time period has passed, such as one or several minutes, then that mobile phone will be considered unqualified. A mobile phone also will be considered unqualified if it loses or drops its signal with a base station for a brief threshold period of time. Similarly, if the historical pattern of movement of a mobile phone suggests the owner/user of the phone is a venue employee, such as exhibiting a regular work schedule over a period of days or weeks, then that mobile phone will be considered unqualified. Further, the mobile phone will be considered unqualified if the owner/user is identified with the police, fire or other municipal authority. Any other means of determining whether a mobile phone is unqualified may be utilized. In circumstances where the determination of unqualified mobile phones is not readily ascertainable, all mobile phones may be considered qualified.
In an alternative embodiment, steps 202 and 203 may be combined in order to count only qualified mobile phones. The filtering and the counting are thus part of the same step. In this regard, only mobile phones are counted that do not belong to venue employees, if this can be determined, and have remained within the venue boundary for a brief threshold period of time.
In step 204 , the CPS 200 estimates the size of the audience by multiplying the count of qualified mobile phones with a predetermined factor. This factor is a number representing a ratio of qualified mobile phone users in attendance to total expected audience size. It is predetermined in the sense that it has already been calculated or is readily calculable at the time it is utilized in step 204 . In the preferred embodiment, the factor is comprised, but not limited to, a penetration rate and an availability rate.
The penetration rate is the ratio of persons possessing a mobile phone to persons not possessing a mobile phone in the general population or among a subset of the population defined by demographic criteria such as age, education, socio-economic status, and geographic location. The penetration rate used in determining the factor may depend on the demographic profile of the audience at a concert at a venue. A means of understanding the demographic profile of an audience is to utilize the popularity profile of a music artist performing at the concert or at comparable past concerts at the venue as provided by the PPS Server 105 , described in U.S. patent application Ser. No. 12/322,625. A typical popularity profile may include the artist's genre of music, demographic information about his fans and supporters, and other information indicative of the type of audience he is likely to attract to the venue.
The availability rate is the ratio of persons in the population who own a mobile phone but whose mobile phone cannot be tracked for some reason, comprising at least the following circumstances: (1) owner forgot or chose not to bring the phone, (2) owner turned off the phone, (3) phone has a dead battery, or (4) phone has a malfunction. The first three items can be reasonably estimated through market studies and surveys of consumer experience with mobile phones. The likelihood of phone malfunction can be reasonably estimated from customer complaint and product return statistics compiled by mobile phone manufacturers and providers.
The size at time t of an audience attending a concert at a venue v, S v,t , can be represented by Equation 1 below.
S v,t = [C total,v,t −C unqualified,v,t ] *F v ( R p,d ,R a,d ), Equation 1:
where C total,t is the total count of mobile phones at time t within the venue boundary of venue v, C unqualified,t is the count of unqualified mobile phones at time t, and F v is the predetermined factor associated with venue v, which is a function of R p,d , the penetration rate for the subset of the population fitting a particular demographic profile d, and R a,d , the availability rate for the subset of the population fitting a particular demographic profile d.
The CPS 200 may also calculate a measure of audience size representing the cumulative audience size for a concert at a venue. This is accomplished in the same manner as above except that the cumulative count for a given time period is used instead of the count at a particular time, as discussed for step 202 . Similar to Equation 1, the cumulative size for the time period t 1 to t 2 of an audience attending a concert at a venue v, S cumulative,v,t1,t2 , can be represented by Equation 2 below.
S cumulative,v,t1,t2 = [C cumulative _ total,v,t1,t2 −C cumulative _ unqualified,v,t1,t2 ] *F v ( R p,d ,R a,d ). Equation 2:
where C cumulative _ total,t is the cumulative total count of mobile phones during the time period t 1 to t 2 within the venue boundary of venue v and C cumulative _ unqualified,t is the cumulative count of unqualified mobile phones during the time period t 1 to t 2 .
In an alternative embodiment, data collected from steps 202 through 204 may be collected from, or in combination with, other mobile phone location data from third party companies such as FourSquare, Twitter and Facebook via their APIs.
FIG. 3 illustrates a typical process for calculating the sentiment of an audience of a concert at a venue in the preferred embodiment of the CPS 200 . At step 301 , the CPS 200 receives sentiment data associated with a concert at a venue. The sentiment data may be retrieved or sent from the Music Scout (software application), Fandom (software application), the PPS Server 105 , described in U.S. patent application Ser. No. 12/322,625, or another source, represented as an information server 103 . This data may be provided in near real-time, at a regular time interval, upon request, or upon the trigger of a concert or action. In the preferred environment, the Music Scout “pushes” or sends sentiment data to the CPS 200 upon being generated by a player.
In step 302 , the sentiment data is classified into two or more categories, The two most basic categories of sentiment are favorable and unfavorable, which can be represented quantitatively as 1 and −1 (or in the alternative, as −1, 0, 1 representing unfavorable, ambivalent/undetermined, and favorable). These categories reflect whether a person's expression of sentiment about an object or activity related to a concert is favorable (positive, affirming, agreeable, approving, pleasing, etc.) or not. The number of categories may be expanded to reflect a greater range of sentiment, such as a five-point rating system as follows: strong disapproval, modest disapproval, ambivalence, modest approval, and strong approval, represented quantitatively as −2, −1, 0, 1, 2. In the preferred embodiment, the Music Scout application operating on a user's mobile phone would present the five categories of sentiment as described above to the user as part of a poll or question in which the user selects one of the categories.
Sentiment data typically consists of at least three types of information: (1) information identifying a particular music concert at a venue, (2) information describing a person's expression of sentiment about an object or activity related to a music concert, and (3) information identifying the source of the sentiment data. In the preferred embodiment, sentiment data received from the Music Scout application consists of at least (1) the name or identifying code of a particular concert at a venue, (2) a numerical rating, (3) information identifying the source as Music Scout, and (4) the time and date.
In step 303 , all sentiment data associated with a concert at a venue is incorporated into a metric or set of metrics that describe the sentiment of the audience at the concert in aggregate. In the preferred embodiment, one metric calculated is the mean value of all sentiment data received from Music Scout for a concert at a particular time. Assuming Music Scout employed a five-point rating system as suggested above, a mean value of 1.0 would suggest an audience sentiment of modest approval. Audience sentiment, Ψ audience , at time t is determined by Equation 3 below.
Ψ
audience
,
t
=
ΣΨ
user
,
n
,
t
1
,
t
2
n
,
Equation
3
where n number of users expressed sentiment Ψ user during time t 1 ≦t<t 2 and
Ψ user ={2, 1, 0, −1, −2}.
Another metric that may be calculated is a statistical confidence level indicating the extent to which the group of persons for which sentiment was measured correlates to the sentiment of the entire audience attending the concert. This may be determined by taking a linear regression of the sentiment measurements collected from the group, wherein the confidence level is derived from the variance of the fitted linear function.
FIG. 4 illustrates the system components of CPS server 101 . The CPS server 101 comprises a user interface module 101 a , a CPU 101 b , a network interface 101 c , a database 101 d , an API Server 500 , and the CPS 200 . The user interface module 101 a and the CPS 200 are software programs that are executed by the CPU 101 b . The user interface module 101 a communicates with client computer 102 via the network interface 101 c , which connects the CPS server 101 to the Internet using a unique IP address. In the preferred embodiment, the user interface module 101 a presents a web page to the client computer 102 that represents the Music Scout application for rendering in a browser. The user interface module 101 a also provides web pages to a client computer 102 for administrative functions such as managing the data and setting the configuration of the CPS 200 . The API Server 101 e communicatively connects to APIs of third party applications. In an alternative embodiment, the CPS server 101 provides information to third party applications, including those other than Music Scout, via the API server 101 e.
The CPS 200 performs analysis on the data contained in database 101 d to determine size, sentiment and any other metrics related to audience characteristics at a music concert, as discussed in the balance of this specification. The CPS 200 is also responsible for sending and retrieving data from the PPS server 105 , described in U.S. patent application Ser. No. 12/322,625. In the preferred embodiment, the CPS 200 sends an audience sentiment metric, described in Equation 3, and a size metric, described in Equation 2, at periodic time intervals to the PPS server 105 , wherein the two metrics are associated with a particular music concert and one or more music artists.
The database 101 d maintains records of at least the following:
(1) Data related to mobile phone locations from AirSage, SkyHook or another mobile phone location tracking company, the data for each mobile phone being tracked comprising:
(a) Unique ID of the mobile phone (anonymized); (b) Geolocation coordinates; and (c) Timestamp.
(2) Venue geolocation boundary coordinates. (3) Concert description information, including city and state location. (4) User registration information (e.g. Music Scout application). (5) Sentiment poll/question results per user, per concert, per time period. (6) Sentiment and size metrics as determined by the CPS 200 .
In an alternative embodiment, the CPS 200 can determine a correlation related to the size and sentiment of an audience at a music concert. One use of correlation is to determine whether sentiment of the audience depends on size, and if so, at what size audience does sentiment change significantly. Correlation between size and sentiment can be determined by known statistical methods in the art. As an example, the correlation between size, X, and sentiment, Y, can be described using Equation 4 below.
ρ
(
X
,
Y
)
=
corr
(
X
,
Y
)
=
cov
(
X
,
Y
)
σ
X
σ
Y
=
E
[
(
X
-
μ
)
]
σ
X
σ
Y
Equation
4
where cov is the covariance, σ is the standard deviation, μ is the mean, and
E is the expected value operator.
It will be clear to one skilled in the art that the above embodiments may be altered in many ways without departing from the scope of the invention. | Technologies are described herein for determining characteristics of a plurality of people at an event. A method may include receiving location information about a plurality of active mobile phones, receiving sentiment information relating to the plurality of people, the sentiment information including at least one identifier of the event, determining at least one characteristic about the plurality of people based at least in part on the location information and the sentiment information, aggregating the sentiment information, classifying the aggregated sentiment information as either favorable or unfavorable with respect to the event, and calculating a statistical confidence level indicating an extent the aggregated sentiment information of the particular group correlates with the plurality of people. The location information may include at least one identifier of a geographical location and a time period. The location information and sentiment information may be collected from a particular group of the plurality of people. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit under 35 USC §119(e) of U.S. Provisional Patent Application Ser. No. 61/101,049 filed 29 Sep. 2008, which application is hereby incorporated fully by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to fabric systems, and more specifically to bed coverings constructed of high gauge circular knitted fabrics that accommodate and maintain optimum thermal conditions for sleep, which in turn can lead to faster sleep initiation and deeper, more restorative sleep.
[0004] 2. Description of Related Art
[0005] Sleep problems in the United States are remarkably widespread, affecting roughly three out of four American adults, according to research by the National Sleep Foundation (NSF). Consequently, a great deal of attention has been paid to the circumstances surrounding poor sleep, along with strategies for how to improve it.
[0006] The implications are not merely academic. Sleep—not only the right amount of it but also the right quality—impacts not just day-to-day performance, but also “the overall quality of our lives,” according to the NSF. Addressing the causes of poor quality sleep, therefore, has ramifications for millions.
[0007] Though many factors contribute to sleep quality, the sleep environment itself plays a critical role, and sleep researchers routinely highlight temperature as one of the most important components in creating an environment for optimal sleep. As advised by the University of Maryland Medical Center, “a cool (not cold) bedroom is often the most conducive to sleep.” The National Sleep Foundation further notes that “temperatures above 75 degrees Fahrenheit and below 54 degrees will disrupt sleep,” with 65 degrees being the ideal sleep temperature for most individuals, according to the NSF.
[0008] A lower environmental temperature is not the only thermal factor associated with improved sleep. Researchers have noted a nightly drop in body temperature among healthy, normal adults during sleep. This natural cycle, when inhibited or not functioning properly, can disrupt sleep and delay sleep onset, according to medical researchers at Cornell University. Conversely, the researchers noted, a rapid decline in body temperature not only accelerates sleep onset but also “may facilitate an entry into the deeper stages of sleep.”
[0009] Therefore, maintaining an appropriately cool sleep environment and accommodating the body's natural tendency to cool itself at night should be a top priority for individuals interested in optimizing their sleep quality. Performance fabrics crafted into bedding applications would be uniquely capable of promoting cool, comfortable—and therefore better—sleep, as these advanced fabrics maximize breathability and heat transfer. Performance fabrics are made for a variety of end-use applications, and can provide multiple functional qualities, such as moisture management, UV protection, anti-microbial, thermo-regulation, and wind/water resistance.
[0010] There has been a long felt need in several industries to provide improved bedding to help individuals get better sleep. Such improved bedding would include beneficial wicking among other properties. For example, in marine, boating and recreational vehicle applications, bedding should resist moisture, fit odd-shaped mattresses and beds, and reduce mildew. Particularly with watercraft, there is a need to protect bedding, and specifically sheets, from moisture and mildew accumulation.
[0011] An additional problem with bedding, not just with marine and recreational vehicles, is the sticky, wet feeling that can occur when the bedding sheets are wet due to body sweat, environmental moisture, or other bodily fluids. In particular, when bedding is used during hot weather, or is continuously used for a long time by a person suffering from an illness, problems can arise in that the conventional bed sheet of cotton fiber or the like cannot sufficiently absorb the moisture. All of these issues lead to poor sleep.
[0012] To date, performance fabric bedding products are not known. There are width limitations in the manufacturing of high gauge circular knit fabrics, because the finished width of bedding fabrics are dictated by the machine used in its construction. At present, performance fabrics are manufactured with a maximum width of under 90 inches wide, given present manufacturing and technical limitations, along with the inability of alternate manufacturing processes to produce a fabric with identical performance attributes. Yet, normal bed sheet panels can be 102 by 91 inches or larger. Thus, performance fabrics cannot yet be used for bed sheets.
[0013] Some conventional solutions for the above issues that hinder a good night's sleep include U.S. Pat. No. 4,648,186, which discloses an absorbent wood pulp cellulose fiber that is provided in a variety of sizes and is placed under a mattress. The wood pulp is water absorbent and acts to capture moisture to prevent such moisture from being retained by the bedding or the bedding sheets. However, this proposed solution does not interact with the bedding or the bedding sheets, but merely acts as a sponge for moisture that is in proximity to the target bedding.
[0014] U.S. Pat. No. 5,092,088 discloses a sheet-like mat comprised of a mat cover, the inside of which is divided into a plurality of bag-like spaces, and a drying agent packed into a bag and contained in the bag-like spaces in such a manner that the drying agent cannot fall out of the bag-like spaces. A magnesium sulfate, a high polymer absorbent, a silica gel or the like can be used as the drying agent. As can be seen, this proposed solution to moisture in bedding is cumbersome and chemically-based.
[0015] In the athletic apparel industry, moisture wicking fabric has been used to construct athletic apparel. For example, U.S. Pat. No. 5,636,380 discloses a base fabric of CoolmaxQ high moisture evaporation fabric having one or more insulating panels of ThermaxB or ThermastatQ hollow core fiber fabric having moisture wicking capability and applied to the inner side of the garment for skin contact at selected areas of the body where muscle protection is desired. However, this application cannot be applied to bedding sheets due to the limitations of the size of the performance fabrics manufactured. Further, performance fabric such as this type cannot be easily stitched together as the denier is so fine that stitching this fabric results in the stitching simply falling apart.
[0016] Circular knitting is typically used for athletic apparel. The process includes circularly knitting yarns into fabrics. Circular knitting is a form of weft knitting where the knitting needles are organized into a circular knitting bed. A cylinder rotates and interacts with a cam to move the needles reciprocally for knitting action. The yarns to be knitted are fed from packages to a carrier plate that directs the yarn strands to the needles. The circular fabric emerges from the knitting needles in a tubular form through the center of the cylinder. This process is described in U.S. Pat. No. 7,117,695. However, the machinery presently available for this method of manufacture can only produce a fabric with a maximum width of approximately 90 inches. Therefore, this process has not been known to manufacture sheets, since sheets can have dimensions of 91 inches by 102 inches or greater.
[0017] Further, the machinery that is used for bedding is very different than for athletic wear. For example, bedding manufacturing equipment is not equipped to sew flatlock stitching or to provide circular knitting. Bed sheets typically are knit using a process known as warp knitting, a process capable of producing finished fabrics in the widths required for bedding. This method, however, cannot be employed to produce high-quality performance fabrics. Warp knitting is not capable of reproducing these fabrics' fine tactile qualities nor their omni-direction stretch properties, for example.
[0018] Circular knitting must be employed to produce a performance fabric that retains these fabric's full range of benefits and advantages. However, in order to produce a fabric of the proper width for bedding applications, a circular knit machine of at least 48 inches in diameter would be necessary. Manufacturing limitations therefore preclude the construction of performance fabrics at proper widths for bedding. The industry is unsure if it could actually knit and then finish performance fabrics at these large sizes, even if the machinery were readily available.
[0019] Further, athletic sewing factories are typically not equipped to sew and handle large pieces of fabrics so that equipment limitations do not allow for the manufacture of bedding sheets.
[0020] What is needed, therefore, is a bedding system that utilizes performance fabrics and their beneficial properties, the design of which acknowledges and addresses limitations in the manufacture of these fabrics. It is to such a system that the present invention is primarily directed.
BRIEF SUMMARY OF THE INVENTION
[0021] Briefly described, in preferred form, the present invention is a high gauge circular knit fabric for use in bedding, and a method for manufacturing such bedding. The bedding fabric has superior performance properties, while allowing for manufacture by machinery presently available and in use. In order to achieve a finished width of the size needed to create sheet-sized performance fabric, a high gauge circular knit machine of at least 48 inches in diameter is necessary. And while warp knitting machines are available that can produce wider fabrics, this method will not provide a fabric with the tactile qualities required, nor provide a fabric with omni-directional stretch.
[0022] In an exemplary embodiment, the present invention is a method of making a finished fabric comprising at least two discrete performance fabric portions, and joining at least two discrete performance fabric portions to form the finished fabric. Forming the at least two discrete performance fabric portions can comprise knitting at least two discrete performance fabric portions, and more preferably, circular knitting at least two discrete performance fabric portions. Joining the at least two discrete performance fabric portions to form the finished fabric can comprise stitching at least two discrete performance fabric portions together to form the finished fabric.
[0023] The at least two discrete performance fabric portions can have different fabric characteristics. Fabric characteristics as used herein include, among other things, moisture management, UV protection, anti-microbial, thermo-regulation, wind resistance and water resistance.
[0024] The finished fabric can be used in, among other applications, residential settings, or in marine, boating and recreational vehicle environments.
[0025] The present sheets offer enhanced drape and comfort compared to traditional cotton bedding, and are as fine as silk, yet provide the benefits of high elasticity and recovery along with superior breathability, body-heat transport, and moisture management as compared to traditional cotton bedding.
[0026] Conventional fitted sheets can bunch and slide on standard mattress sizes. Furthermore, if the fitted bed sheets do not fit properly, they do not provide a smooth surface to lie on. The present invention overcomes these issues.
[0027] The present high gauge circular knit fabrics stretch to fit and offer superior recovery on the mattress allowing the fabric to conform to fit the mattress without popping off the corners of the mattress or billowing. The performance fabric can include spandex, offers a better fit than conventional bedding products, can accommodate larger or smaller mattress sizes with a single size sheet, and can conform to mattresses with various odd dimensions.
[0028] Spandex—or elastane—is a synthetic fiber known for its exceptional elasticity. It is stronger and more durable than rubber, its major non-synthetic competitor. It is a polyurethane-polyurea copolymer that was invented by DuPont. “Spandex” is a generic name, and an anagram of the word “expands.” “Spandex” is the preferred name in North America; elsewhere it is referred to as “elastane.” The most famous brand name associated with spandex is Lycra, a trademark of Invista.
[0029] The present high gauge circular knit fabric offers durability in reduced pilling and pulling when compared to other knit technologies, and offer reduced wrinkles and enhanced color steadfastness
[0030] In a preferred embodiment, the present performance fabric can allow for a one-size fitted sheet that can actually fit two different size mattresses. For example, the full fitted sheet of the present invention can fit on both the full and queen size bed. The twin fitted sheet of the present invention will also fit an XL twin. In a boating application, the present invention can be produced to fit almost every custom boat mattress.
[0031] Testing of the present invention conducted at the North Carolina State University (NCSU) Center for Research on Textile Protection and Comfort confirms that the present performance fabrics provide a cooler sleeping environment than cotton. Performance bedding was tested side-by-side with commercially available cotton bed sheets in a series of procedures designed to measure each product's heat- and moisture-transport properties, as well as warm/cool-to-touch thermal transport capabilities.
[0032] Across all tests, the present performance fabrics in bedding outperformed cotton, demonstrating the performance fabric's superiority in establishing and maintaining thermal comfort during sleep. This advantage is evident to users from the very onset, as NCSU testing indicates that, on average, performance bedding of the present invention offers improved heat transfer upon initial contact with the skin, resulting in a cooler-to-the-touch feeling.
[0033] During sleep, high gauge circular knit performance bedding of the present invention helps to maintain thermal comfort by trapping less body heat and breathing better than cotton. Testing has demonstrated that performance bedding made out of performance fabrics transfers heat away from the body up to two times more effectively than cotton. This is critically important not only for sustained comfort during sleep, but also in terms of enabling the body to cool itself as rapidly as possible to facilitate sleep onset. In addition to trapping less heat, performance bedding breathes better than cotton—up to 50% better, giving performance bedding a strong advantage in terms of ventilation and heat and moisture transfer.
[0034] The performance advantage over cotton holds true for simulated dry and wet skin conditions, confirming that certain performance fabrics in bedding are better suited than cotton at managing moisture (e.g., sweat) to maintain thermal comfort. In addition to wicking moisture away from the skin through capillary action, the performance fabric's advanced breathability further enables heat and moisture transfer through evaporative cooling. As a result, the user is kept cooler, drier and more comfortable than with cotton.
[0035] The present performance bedding holds a distinct advantage over cotton in enabling, accommodating and maintaining optimum thermal conditions for sleep, which in turn can lead to faster sleep initiation and deeper, more restorative sleep.
[0036] These and other objects, features and advantages of the present invention will become more apparent upon reading the following specification in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0037] FIG. 1 illustrates a preferred embodiment of the present invention.
[0038] FIG. 2 illustrates another preferred embodiment of the present invention.
[0039] FIG. 3 illustrates a further preferred embodiment of the present invention.
[0040] FIG. 4 illustrates another preferred embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0041] Although preferred embodiments of the invention are explained in detail, it is to be understood that other embodiments are contemplated. Accordingly, it is not intended that the invention is limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, in describing the preferred embodiments, specific terminology will be resorted to for the sake of clarity.
[0042] It must also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. For example, reference to a sheet or portion is intended also to include the manufacturing of a plurality of sheets or portions. References to a sheet containing “a” constituent is intended to include other constituents in addition to the one named.
[0043] Also, in describing the preferred embodiments, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
[0044] Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value.
[0045] By “comprising” or “containing” or “including” is meant that at least the named compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named.
[0046] It is also to be understood that the mention of one or more method steps does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Similarly, it is also to be understood that the mention of one or more components in a fabric or system does not preclude the presence of additional components or intervening components between those components expressly identified.
[0047] Referring now in detail to the drawing figures, wherein like reference numerals represent like parts throughout the several views, the present invention of FIGS. 1 and 4 provides a sheet 10 shown having dimensions of 102 inches in length and 91 inches in width. The material is manufactured from performance fabric, which can include, for example, varying amounts of one or more of Lycra, Coolmax, Thermax and Thermastat. In a preferred embodiment, the fabric is treated so that the fabric has antimicrobial properties. By using circular-knit performance fabric, the fabric is able to provide elasticity in all four directions. This property allows for the sheet to fit extraordinary mattress, cushion and bedding shapes, as well as providing better fits for traditional rectangular sheets. By using performance fabrics, the sheet has elastic properties that allow stretching in the directions shown as 30 . In addition, by using circular-knit performance fabric, the resulting bedding retains an exceptionally fine tactile quality critical for providing maximum levels of enhanced comfort.
[0048] An alternative to circular knitting is non-circular knitting—for example, warp knitting. This method can achieve widths greater than circular knitting. Industrial warp knit machines, for example, can produce tricote warp knit fabrics up to 130-140 inches in width. Circular knitting, however, is less expensive, as it requires less set-up time. Circular knitting also provides greater multidirectional stretch.
[0049] In order to provide a sheet that exceeds the maximum dimensions of fabric that can be produced by available circular knitting machines, flat lock stitching 12 is used to join a plurality of portions resulting in a sheet that is 91 inches wide (as shown). In an exemplary embodiment, piping 11 can be included in close proximity to the stitching. The stitching can be the same color as the fabric of the sheet portions, or different color(s). The piping can be ¾ inch straight piping without a cord or other filler. In one preferred embodiment, the stitching is 16 stitches per inch. Piping 11 can be included at one end of the sheet and can be the same or a different color as the sheet fabric.
[0050] For a fitted sheet, the sheet can include an elastic portion surrounding the edge of the fitted sheet to better keep the fitted sheet in place when placed on a mattress or other sleeping surface. A cord can be sewn into the edge of the fitted sheet and cinched around the mattress or other sleeping surface to better hold the fitted sheet in place.
[0051] Referring to FIG. 2 , a sheet is shown having dimensions of 91 inches wide and 102 inches in length. In this embodiment, stitching 14 is shown 34 inches from an interior edge 18 of a main portion 16 and another stitch 14 at edge 20 of the sewn-on portion. Flat lock stitching can be used for the stitching. Piping can be applied at or in proximity to the stitching.
[0052] Referring to FIG. 3 , a non-rectangular shaped sheet is shown. In this exemplary embodiment, elastic can be included around the edge of the fitted sheet to better maintain the fitted sheet in position when placed on a sleeping surface. In one embodiment, pull ties 24 can be installed at various locations around the edge of the fitted sheet in order to assist in maintaining the fitted sheet secured to the sleeping surface. The pull tie can be cinched to increase tension around the edge of the fitted sheet as shown by 26 .
[0053] Stitching used for securing the portions of the sheet together can include that shown as 28 a . In another embodiment, the stitching used for securing the portion of fabric together is shown as 28 b.
[0054] Referring to FIG. 4 , yet another preferred embodiment of the invention is shown. In this embodiment, the sheet can be assembled through stitching of differing fabrics for generating performance zones in the sheet. For example, zone 32 can have higher wicking properties than the other zones since this area is where the majority of the individual body rests. Areas 34 a through 34 d can have higher spandex or other elastic fabric properties so that the fit around a sleeping surface is improved. Area 36 may have thermal properties such as increased cooling since this area is generally where the individual's head lies. In an exemplary embodiment, the pillow covers of pillows used by the individual also have differing properties from the remainder of the sheet, e.g., thermal properties.
[0055] The present invention encompasses the construction of bedding materials that have superior performance properties while allowing for manufacture by machinery presently available and in use. More specifically, the invention is related to a new method for fabricating a covering and or sheets in bedding. When using the circular knitting machine, the high gauge performance fabrics can only be made to a maximum size of 72.5 inches without losing the integrity of the spandex in the fabric. Yet, normal sheet panels are 102×91 inches. This presents problems when manufacturing sheets from performance fabrics.
[0056] Additionally, special stitching techniques must be used given the thread density of the fabric. Using this special stitching, panels are sewn together to produce bedding or a sheet that is the proper size for standard bed sheets. Because discrete portions/panels are used in the manufacture of the present fabrics, panels can be selected that provide different properties for different areas of the bedding ( FIG. 4 ). Stitching or seams on the sheet can also allow for the ease of making the bed. Because the bedding is made from performance fabric with spandex, it stretches to permit multiple and custom sizing for applications in cribs, recreational vehicles and boats.
[0057] Circular knitting machines used for high gauge performance bedding fabrics are called high-gauge circular knitting machines, because of dense knitting with thin yarn. High gauge generally denotes 17 gauges or more. Seventeen gauges indicate that 17 or more cylinder needles are contained in one inch. Circular knitting machines of less than 17 gauges are referred to as low-gauge circular knitting machines. The low-gauge circular knitting machines are often used to knit outerwear.
[0058] “Yarn count” indicates the linear density (yarn diameter or fineness) to which that particular yarn has been spun. The choice of yarn count is restricted by the type of knitting machine employed and the knitting construction. The yarn count, in turn, influences the cost, weight, opacity, hand and drape of the resulting knitted structure. In general, staple spun yarns tend to be comparatively more expensive the finer their count, because finer fibers and a more exacting spinning process are necessary in order to prevent the yarn from showing an irregular appearance.
[0059] A top width in the 90-inch range is currently possible using a circular knit fabric formed on a 36-38-inch diameter machine, although higher levels of spandex in the performance fabric tend to pull the width in. In just one example, on a 30-inch diameter machine, the spandex can reduce an otherwise 94-inch circumference fabric tube to one with a 60-65 inch finished width.
[0060] A major limitation in finished width is not strictly a knitting concern but also concerns finishing. With performance fabric, it tends to sag in the middle—increasingly so with greater widths—making finishing difficult to impossible above a certain threshold. A possible 90-inch finished width is contingent upon having a good finishing set-up capable of handling the present performance fabric. This potential for difficulties would only become compounded at the larger widths required for bed sheets.
[0061] In a preferred process, the present fabric undergoes a heat setting finishing process. Applying a moisture-wicking finish to another fabric—like cotton—that can be produced at larger widths appears unlikely to match the moisture-control properties of the present fabric, as polyester itself is naturally moisture-resistant and there are physical actions (e.g. capillary action) at play. Further, the use of cotton comes at the expense of breathability and heat-transfer capabilities (as confirmed by laboratory testing) and stretchability.
[0062] Numerous characteristics and advantages have been set forth in the foregoing description, together with details of structure and function. While the invention has been disclosed in several forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions, especially in matters of shape, size, and arrangement of parts, can be made therein without departing from the spirit and scope of the invention and its equivalents as set forth in the following claims. Therefore, other modifications or embodiments as may be suggested by the teachings herein are particularly reserved as they fall within the breadth and scope of the claims here appended. | Bedding material including a first fabric section manufactured from performance fabric and having a first and second side; and, a second fabric section attached to the first side of the first fabric section. Additionally, a third fabric section can be attached to the second side of the first fabric section. The first fabric section can be attached to the second fabric section through a flatlock stitch. The first fabric section can include a first zone and a second zone wherein the first zone contains different performance properties from the second zone and the first zone can have thermal or moisture wicking properties. | 3 |
FIELD OF THE INVENTION
The present invention relates to gaseous fuel combustion systems and in particular to a method and apparatuses in accomplishment of same, for controlling the combustion to obtain: flame stability, low emissions, in the most wide field of burner capacity modulation required in practice, even in feeding conditions with limit gases, in a so simple and practical way to be used also for apparatus with capacity of only few KW.
The gas combustion system is the assembly of the burner with, the combustion chamber, the heat exchanger, the means for the circulation of air and exhausts, if existing, as well as the control apparatus with its sensors; more elements of the assembly can form a sole body therefore a distinction only possible for functions.
The gas combustion systems are the main functional assembly of domestic and industrial appliances as central heating boilers, water heaters, of two main types: istantaneous and storage water heater, room heater and furnaces, gas cookers etc..
For burner it is understood the fictional assembly of the parts which create the mixture of air and fuel-gas and make possible the outflowing of them in the combustion chamber through the flame openings.
The invention applies in particular to fuel-gas combustion systems, where the mixture, formed by air, said primary air, and fuel gas (hereafter simply said mixture) is by approx. stoichiometric to strongly hyperstoichiometric (0.95<λ<1.6, where λ is the ratio between air actually present in the mixture and the air existing in the stoichiometric mixture of the same gas in the same conditions); flow in combustion chamber, out from the flame openings of the burners with substantially laminar flow, having an out flow velocity between 0.2 and 4.0 meter per second, and generates a lamellar flame, means of big surface and minimum thickness (magnitude order of a millimetre), this means that the ratio surface thickness is well over a value of ten, substantially detached from the area occupied by the flame openings; the flame front, that is the surface where the combustion starts, coincides with the flame itself being the combustion monostadium for the presence of all the necessary oxygen since the ignition and is from laminar to wrinkled. The invention applies to combustion systems with gas atmospheric burners but also with forced burners, where the air gas mixture is obtained, in the wanted flow and composition, with the help of auxiliary means (for example fans, or compressors) both types operate either with the presence of secondary air (called partially pre-mixed burners) or with only primary air (called totally pre-mixed burners). In all types of burners the mixture outflows from the flame openings with a velocity fairly higher to the flame speed so as to avoid that the flame adheres to the opening itself (flame substantially detached).
In the combustion chamber the mixture ignited, at least initially, by suitable ignition devices, forms the flame which is kept in stability conditions from a sort of anchorage system, acting at least in some points. Opening configurations, in particular slots obtained in thin thickness sheet, so close to create an almost homogeneous sole jet of mixture are considered single flame opening. The front of flame is recognisable because it emits in the visible, even if the specific maximum emission due to OH and CH ions is respectively in the wavelength between 305 and 320 mm and around 431.5 and 438 mm.
BACKGROUND OF THE INVENTION
A problem arises when instead of the standard fuel-gas for which the apparatus is set, a fuel-gas from the same family as said standard fuel-gas but prone on flame blow-off or prone to flash back are fed. Specifically, the burner flame openings surface may attain critical temperature value, and in some other occasion, the flame may become unstable, resulting in poor combustion of fuel-gas.
A method, applicable to highly premixed but only atmospheric burners, to maintain stable the temperature of the flame openings and reduce the harmful emissions by the variation of --λ-- in the mixture according to the temperature of the flame openings itself is described in the European patent of the author EP0606527A1 deposited on Aug. 16, 1993, but don't take into consideration the flame, its position, shape or density, particularly is not considering a lamellar flame detached from the area of the flame openings.
It is also known a method described in patent DE3630177 dated Sep. 4, 1986 where the signal of the ionisation current, inside the large volume of a turbulent flame, is used for the variation of --λ-- nevertheless it is a signal relating to the combustion conditions inside the big volume of the turbulent flame itself, not of the ionisation conditions of the unburned mixture just upstream the flame front, so at conditions prior to the combustion. This signal is typical of the combustion conditions, specifically as to the limit of stability for the turbulent combustion, don't give any information about the position of the flame front or the flame distance. Furthermore the considered emission of UV, without description of how it is and how it can be used, would seem to determine the combustion condition as to the limit of the stability for turbulent combustion.
Control systems which vary the total quantity of air or of primary air basing itself on a temperature in combustion chamber, on the excess of air in fuels, either combined or not with air variation according to the flow rate of fuel-gas fed, are known. However none of these take into account the influence of gases different from the standard one which can be distributed in sequence without notice and therefore feed the combustion system, nor can they maintain the stability of the flame in large ranges of capacity modulation, nor take into account the combustion of a hyperstoichiometric mixture in substantially laminar flow, particularly with lamellar flames.
These latter control systems and similar ones are complex, in particular for the type and positioning of the sensors, consequently, too expensive for gas appliances of flow limited to even few KW.
None of the previously considered control systems take into account the temperature as well the outflow velocity of the mixture.
DISCLOSURE OF INVENTION
The aim of this invention is to provide a method and apparatuses in fulfilment of same, for the control of the flame position driving the value of at least one of the variable quantities characteristic of mixture outflowing from the flame openings into the combustion chamber; --λ, the velocity, the temperature; in eliminating the aforementioned difficulties it makes possible the proper regulation also in very compact combustion systems, even forming a sole body.
This aim is reached by applying the method so that, having a method for the regulation of a combustion system where the fuel-gas air mixture, wich is from almost stoichiometric to strongly hyperstoichiometric, outflows from at least one flame opening of a premixed burner, with velocity and modalities such as to obtain a lamellar flame, substantially detached from the area of at least one flame opening; characterised by the fact that to maintain the flame around a prefixed optimum position at least one of the three variable quantities of the mixture is varied: the value of premixture rate λ, the outflow velocity, the temperature upstream the flame front.
It is possible to define the position of the flame as the distance between the barycenter of the flame front and the surface of at least one flame opening which generates this front, hereafter said quantity will be called flame distance.
The flame distance optimum value can generally be predetermined arbitrary constant, but can have different values according to the fuel-gas flow rate; in any case, during the on periods on the combustion system, the instantaneous ratio, which is the detected flame distance/optimum flame distance, have the value 1 for the reached conditions considered as optimum, values over 1 show a tendency of the flame to blow-off increasing as the ratio increases, values under 1 show the tendency to overheat the burner head increasing as the ratio decreases.
The istantaneous ratio: detected flame distance/optimum flame distance, will be hereafter called flame ratio.
To obtain the regulation desired at least one of said variable quantities of the mixture is varied according to the flame ratio as per the following modalities:
the λ premixture value is varied between a prefixed minimum and maximum value according to the flame ratio, a flame ratio>1 causes a λ decrease and vice versa;
the outflow mixture velocity is modified through the variation of the outflow cross section of at least one flame opening, between a minimum section and a maximum one, according to the flame ratio, a flame ratio>1 causes an outflow section increase and vice versa.
the temperature, of the mixture outflowed from at least one flame opening, between a prefixed minimum and maximum value, is varied, upstream the flame front, according to the flame ratio, a flame ratio>1 causes a mixture temperature increase and vice versa.
The regulation method of the invention can detect the quantity indicative of the flame distance, through the position of the radiation source in the different frequencies of the flame itself, through the temperature detected at least upstream the flame front and in the immediate proximity of said front and through the ionisation current measured at least upstream the flame front and in the immediate proximity of said front at least in average value.
In a first variant, the value of the premixing rate λ is changed between prefixed minimum and maximum values according to the flame ratio, a flame ratio>1 causes a λ decreases and vice versa, so as to maintain said flame distance around a given value, except for different regulation during temporary periods, for example during starting, when needed.
In particular in case of use of a sole fuel-gas and with constant cross-section of the flame opening(s), the prefixed maximum and minimum values corresponds respectively to the minimum flow and maximum flow of the burner.
It is also provided a simplified regulation, at steps, which varies λ between a minimum value and a maximum one if said flame distance either decreases or increases respectively.
A modified regulation can provide, at ignition, to increase the flame speed that otherwise would be too low, a mixture temperature increase obtained with heat transfer to the mixture brought to such a value to obtain the first and the cross-ignition, the heat transfer can remain as such for a determined period, for example for 10 seconds, or for wall temperatures of the flame opening below a given value.
By adopting the variation of the λ value in mixture, as described, if the composition of the fuel-gas feeding and/or the temperature of the mixture and also the cross-section of the flame opening(s) do not change, variation of outflow-velocity of the mixture remains in reduced limits, for the reasonable range of burner modulation, with small movement of the flame front, even without any further regulation.
In a second variant a basic value of λ is defined in linear relationship to the fuel-gas flow rate, detected through the fuel-gas injector pressure, corrected, between prefixed minimum and maximum deviation, according to the flame ratio, different regulation during temporary periods, for example during starting, is provided, when needed.
In a third variant, to enlarge the capacity modulation field of the combustion system even to a modulation ratio 1/10, besides the λ variation as per above first variant, the outflow velocity of the mixture is maintained almost constant by changing the cross section of at least one flame opening according to the instantaneous flow-rate of gas however detected (for example by using the flame density) . Where the flame density is the specific concentration of the combustion and, if other parameters do not change, is index of the instantaneous gas flow rate.
In a fourth variant, together with the regulation as per first variant, it is also possible to vary the outflow velocity of the mixture from the flame openings, according to the temperature of the openings(s) by reducing the section at an increase of the temperature and vice versa.
In all the previous variants, changes of the conditions of the flame stability at constant fuel-gas flow rate, due to a modification of the flame speed for the change of the composition of the gas employed and/or of the temperature of the mixture (for example: for temperature changes of the inlet air), cause a deplacement of the flame front, and, because the relation between λ and the flame position, a correction of the λ value is obtained such as to restore the stability conditions of the flame.
At ignition, in order to improve the stability conditions, the λ value is the minimum provided and can stay as such for a fixed period, for example for at least ten seconds, or for wall temperatures of the flame openings below a certain value, for example around 200° C., then modifying itself according to the flame position.
A fifth variant of the method provides that the outflow cross-section of the flame opening/s is varied according to the flame ratio, between a minimum and a maximum cross-section, causing a flame ratio>1 causing an outflow section increase and vice versa, so as to maintain the flame distance around a pre-fixed value, except for a different regulation during the transient periods, for example of starting, when needed.
A simplified regulation which, according to the flame ratio, varies the outflow cross-section of the flame openings between a minimum value and a maximum one, in one or more steps, opening or closing one or more flame openings if said flame ratio increases or decreases is also provided.
By adopting the flame ratio, or any variable quantity which follows the same variation law, as control-parameter for the variation of the outflow cross-section of the flame opening/s, it is possible to reduce at the minimum the variation of the outflow velocity at the change of the burner capacity by maintaining the flame stable and the emissions reduced.
If the composition of the feeding gas and/or the temperature of the mixture do not change, in particular in atmospheric burners, through the continuous variation of the mixture outflow velocity, as previously described, the value of λ in the mixture itself is maintained in reduced limits, in a range of burner capacities, favourably keeping almost fixed the flame front, without any further regulation.
Changes of the stability conditions of the flame at constant burner capacity, due to variation of the flame speed for the change of λ and/or of the composition of the feeding gas and/or of the mixture temperature, cause a correction of the outflow cross-section, such as to favour the restoration of the stability conditions of the flame, that means increase of the outflow section in case of decrease of the flame speed and therefore tendency for the flame to blow-off and the opposite if said speed increases that means a tendency for the surface of the flame opening/s to overheat.
When the burner is in off condition the cross-section of the flame opening(s) can be the maximum possible and can remain as such for a pre-fixed period, for example for approximately ten seconds, during the ignition phase, then modifing according to the regulation law.
Otherwise in order to improve the stability conditions in transient periods, the modifications of the outflow cross-section can't happen for temperatures of flame openings below a pre-fixed value, usually around 200° C., to obtain an outflow velocity of the mixture lower than the one provided at steady state.
Sixth variant: at the ignition, modifying the fifth variant, the flame speed can be increased through the increase of the mixture temperature, obtained with heat transfer to the mixture, brought to such a value to obtain the first and the cross-ignition; after the ignition, the heat transfer can remain as such for a determined period, for example for 10 seconds, or for wall temperatures of the flame opening below a given value, then will change to drive the mixture temperature according to the variation of fuel-gas flow rate.
Seventh variant: since it has been surprisingly noticed that, in a reasonable range of working conditions, the wall temperature of the flame opening/s or of a body in its immediate vicinity, varies with a law comparable to that of the variation of the flame distance, also the temperature of these bodies compared to an optimum value, according to the invention, can be used as regulation parameter of the outflow cross-section of the flame opening/s variation, by detecting it with thermocouples, thermistors or other.
By increasing the temperature of the flame openings compared to a predetermined value, the method of the invention decreases the outflow cross-section tending to restore the lost equilibrium, by decreasing the temperature ratio it increases said cross-section, when the burner is in off condition the outflow cross-section is the maximum provided.
Controlling in His way the mixture outflow velocity, the temperature of the zone of the flame opening/s it maintains, within acceptable limits (even below 500° C.), the flame stable the emission low, in a reasonable range of burner flow modulation and of kind of feeding gases.
On the eighth variant: the value of the temperature of the mixture upstream the flame front is varied according to the detected flame ratio, causing an increase of the flame ratio an increase of the temperature and vice versa, so as to maintain said flame distance around a given value, except for different regulation during temporary periods, for example during the starting, when needed.
It is also possible a simplified regulation, on-off, which increases the temperature to a maximum one if said flame ratio increases over a predetermined value and during the starting periods.
By adopting either the flame ratio, or any quantity which follows the same variation law of the flame position, as control-parameter for the variation of the mixture temperature, if the composition of the fuel-gas, and/or λ in the mixture and also the cross-section of the flame opening(s) do not change, for the complete range of burner capacity modulation, small movement of the flame front is obtained, even without any further regulation because to a variation of outflow velocity is opposed a flame speed variation in opposite direction.
Changes of the stability conditions of the flame at steady state due to variation of the flame speed for the change of λ and/or of the composition of the feedgin fuel-gas cause a correction of the value of the temperature of the mixture, such as to favour the restoration of the stability conditions of the flame, that means temperature increases in case of decrease of the flame speed and therefore tendency to blow-off of the flame, the opposite if said speed increases that means a tendency to overheating of the surface of the flame opening.
Ninth variant: It is however possible to enlarge the flow modulation field of the combustion system if, besides the regulation as above foreseen, either λ or the outflow velocity of the mixture are varied according to the instantaneous fuel-gas flow-rate, anyhow detected, almost constant λ slightly decreasing the outflow velocity by an increase of the gas flow rate and vice versa; acting so the capacity modulation ratio can even go up to 01/1,.
Tenth variant the method of the invention carries out the temperature variation associated with the variation of the λ value in the mixture or its outflow velocity, all variating according to a quantity, index of the flame ratio as previously described.
Eleventh variant Associated with the temperature variation also it can be varied the outflow velocity of the mixture from the flame openings, according to temperature of the openings decreasing the section by increasing the temperature and vice versa.
At ignition to increase the flame speed that otherwise would be sometime too low, the heat transfer to the mixture can be brought to the maximum value provided to obtain the first ignition and cross-ignition, can remain as such for a determined period, for example for 10 seconds, or for wall temperatures of the flame opening below a given value, for example around 200° C., then be reduced to obtain the temperature of the mixture according to the flame ratio.
By using any variant of the described method, the temperature of the outflow zone of the mixture remains within acceptable limits (even below 400° C.), at any flow condition of the burner, type of feeding gas, temperature of the inlet air the flame remain stable, the harmful emissions are reduced to minima values.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to better understand the invention, its characteristic and the advantages it provides, few embodiments thereof are described hereinafter, by way of non limitative example and with the assistance of the appended drawings, in which
FIGS. 1-3 illustrate a combustion system with totally premixed atmospheric burner, forced draught, λ variation according to the flame distance. FIG. 1 is a general scheme, FIG. 2 detail of the by-pass, FIG. 3 view of the flame openings.
FIGS. 4-6 illustrate a combustion system with totally premixed forced burner, λ variation according to the flame ratio and to the instantaneous air flow rate. FIG. 4 is a general scheme, FIG. 5 view of the flame openings. FIG. 6 detail of the air-gas regulation.
FIGS. 7-9 illustrate a combustion system with atmospheric burner partially premixed, natural draught, λ variation according to the flame ratio and variation of the outflow velocity according to the temperature of the flame opening. FIG. 7 is a general scheme, FIG. 8 detail of a flame opening, FIG. 9 detail of the λ regulation system with a sliding sleeve around the fuel-gas delivery nozzle.
FIGS. 10-12 illustrate a combustion system with atmospheric burner, forced draught, λ variation according to the flame ratio and outflow velocity according to the fuel-gas flow rate, or vice versa, FIG. 10 is a front view, FIG. 11 a side view, FIG. 12 a cross section of a flame opening.
FIGS. 13-16 illustrate two combustion systems with atmospheric burners, one with natural draught the second with forced draught, variation of the outflow velocity according to the the temperature of the flame opening FIG. 13 shows a view in vertical cross section of a natural draft combustion system with variation of the outflow cross section according to the temperature of the exit area of the flame openings using bimetallic strips, FIG. 14 shows an enlargement of a flame opening of FIG. 13; FIG. 15 shows a view in vertical cross section of a forced draft combustion system where a bulb according to the reached temperature modifies the outflow cross section of flame openings FIG. 16 shows an enlargement of a flame opening of FIG. 15.
FIGS. 17-19 illustrate a burner of the extractible type with variation of the outflow cross section according to the temperature of the exit area of the flame openings using bimetallic strips FIG. 17 shows a burner in longitudinal view with a single flame opening interrupted by bimetallic U formed bridges which by tightening the lips of the flame opening modify its cross section, FIG. 18 shows the same burner without the flame to a better comprension of the mecanism and FIG. 19 shows a cross section of a slightly different burner
FIG. 20 illustrates a combustion system with variation of the mixture temperature according to the flame ratio; the mixture is heated by a wire heating element positioned in the combustion chamber, covering its plan with mesh, FIG. 21 shows an enlarged plan view of the burner head.
FIG. 22 illustrates shows a pressurised combustion system with variation of the mixture temperature according to the flame ratio and where λ is maintained steady at the changing of the instantaneous fuel-gas flow rate; the mixture is heated by a heating element inside the burner. FIG. 23 shows a forced draught combustion system with variation of the mixture temperature and of λ according to the flame ratio, the mixture is heated by a heating element which acts also as fluids dynamics obstacle.
FIGS. 24-27 illustrate a forced draught combustion system with variation of the temperature and of the outflow velocity of the mixture according to the flame ratio, the mixture is heated by a heating element downstream the flame openings which also acts as fluids dynamics obstacle.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows, in vertical cross section A--A a combustion system operating in forced draught with the fan 4 working at constant spin velocity mounted downstream the heat exchanger 2 so the inside of the shell 5 is in depression compared to the outside. The burner 8B, (FIG. 4) the body of which is bottom part of the shell 5, is atmospheric, the air-fuel gas mixture is obtained in a Venturi type tube 10A from the fuel gas exiting the injector 23 and the air from outside the shell 5 entering the mouth 9A. Under the vacuum created by the fan in the combustion chamber 3 with respect to the region outside the shell 5 the mixture is drawn through the Venturi 10A and the mixing chamber 18 to the flame openings 7A, better described in FIG. 3, obtained on the sheet metal, for examples of 0.4-0.6 mm thickness, of the burner head 6.
The flame openings 7A, made of a row of slots each, are spaced centre to centre from 15 to 60 mm to obtain a flying carpet type lamellar flame 19 anchored to external obstacles 12A, visible in V shaped cross section with upstream vertex and centreline of the V, perpendicular to the surface and in centre of the flame openings, parallel to the rows and distant to the slot surface from few to some ten mm according to the cases.
The lamellar flame covers the plan of the combustion chamber 3, lying at level of the optical sensor 14B. The process controller 15 varies the gas flow through the valve 11, according to the heat request and varies λ in the mixture, acting through the by-pass 24 better described in FIG. 2. The open cross section of the by-pass 24 varies with the rotation due to a step by step motor 25, the more the by pass is opened the lower value of λ is obtained. The process controller 15 acts positioning first the by-pass 24, to obtain the minimum value of λ to facilitate the ignition, then, after some ten seconds, changing the by-pass position, according to the flame ratio, an increase of the flame ratio causing a decreasing of λ and vice versa, in order to maintain the flame distance around a pre-fixed optimum value.
Using a different process controll the process controller 15 can also act in a different way: first positioning the by-pass 24 to obtain the minimum value of λ to facilitate the ignition, then after some ten seconds positioning the by-pass 24 to obtain a predetermined value of λ related to the instantaneous fuel gas flow rate, but changing the by-pass position to obtain a λ deviation between a pre-fixed minimum and maximum, according to the flame ratio.
The optical device 14B, based on photo sensor/s, transmits to the process controller 15 one signal corresponding to the detected position of the flame compared to a pre-fixed position, means the flame ratio, and another one proportional to the intensity of the flame radiation, in particular proportional in the radiation frequencies characteristic of OH, CH, C2 radicals.
According to the heat request, the controller 15 varies the instantaneous fuel-gas flow rate by a valve 11 with variable opening, and controlled using the radiation intensity measured by the optical device 14B; the λ value is varied by the by-pass position according to the fuel gas flow, verified by the radiation intensities of OH and C2 compared between them or with total radiation. The flame position can be detected with a single photosensitive element through the oscillation of the optical system with known frequency and amplitude.
In FIG. 2 is described the air flow through the by-pass 24, constituted by a cylinder with closed heads whose vertical rotation axis 24B lies on the surface of the shell 5 side wall where a window 24C is open, above the heat exchanger 2, with lips towards the inside 24D.
The cylinder side surface being removed for less than 180°; rotating the cylinder anticlockwise, from a nil passage position (wall closed 24E at the outside of the shell 5) we arrive with a rotation of about 120° to a maximum open passage (as in figure), the shape of the opening 24A is such to obtain an air flow into the shell 5, proportional to the rotation angle, in order to simplify the X variation; for maximum gas flow the passage is almost closed, for minimum gas flow open as in figure, in ignition phase the opening is greater than what requested at steady state for the corresponding gas flow, staying in this position for example from 10 to 30 seconds.
FIG. 3 is a top view B--B in two levels, of a part of the burner's head 6, two flame openings 7A are represented, made of two rows each of parallel slots having width from 0.5 to 0.75 mm and length from 5 to 15 mm, parallel adjacent on the long side, spaced centre to centre from 0.9 to 1.5 mm.
FIG. 4 shows, in vertical cross section, a combustion system 1 with a heat exchanger 2, a combustion chamber 3, a fan 4 for the air gas and exhausts circulation, put upstream the combustion chamber for which this is in over pressure compared to the outside of shell 5, whose inferior part together with the burner head 6 forms the burner 8B body; flame openings 7A better described in FIG. 5, are lengthened, perpendicularly to the drawing surface, formed by two rows of slots each, punched on the sheet metal of the burner head 6. The lamellar flame 19, ignited by a device not in the figure, generates and remains firmly anchored downstream of the flame openings 7A becoming like a wave shaped flying carpet.
The fuel gas valves 11 and 11A (better analysed in FIG. 6) and the fan 4 speed are operated by the process controller 15 according to the signals transmitted by the ionisation current sensor 14A positioned in the volume just upstream flame 19. The sensor has two electrodes, but could have more if needed to enlarge the area under control and have a better definition, transmits the signals which the process controller 15 works out to obtain the average ionisation current values which define the flame distance according to a pre-fixed value, and to obtain amplitude and frequency of oscillation which together with average current value define the flame density, indicator of fuel gas instantaneous flow rate which is used as feedback in the process control.
FIG. 5 shows, from top view, a part of the head burner 6 with three flame openings 7A, obtained from slots punched on thin sheet metal, each made of two rows 7AI and 7AII of parallel slots having width from 0.5 to 0.75 mm length from 5 to 15 mm being adjacent on the long side, spaced centre to centre from 0.9 to 1.5 mm being adjacent on the long metal of 0.4-0.6 mm thickness, which leave in between an unpunched strip 12C, as an example, the 12C width is between 2 and 6 mm. The fluids dynamic obstacle 12C generating downstream a stagnation area, anchors the flame, the openings 7A being parallel double rows close enough, having centre to centre distance from 30 to 120 mm (according to the slots length), generate a wave shaped carpet lamellar flame (19 in FIG. 4) with depression on the vertical of 12C peak half between two adjacent openings 7A.
FIG. 6 is an enlarged section of the air-gas regulation system of FIG. 4 where 11A is the on-off valve which allows the fuel-gas to enter the membrane device 26. Inside the device the menbrane 26B balances the PA pressure upstream the diaphragm 27 of the air exiting the fan 4, trasmitted through the connection pipe 26C, with the PG pressure of the fuel-gas exiting the device 26. The fuel-gas then goes through a variable flow valve 11 downstream which the fuel-gas pressure value becomes PGF<PG , the pressure value PGF determines the instantaneous fuel gas flow rate.
The variation of the heat request causes a variation of fan spin velocity, therefore a different air flow rate, a different PA1 pressure and a consequent PG1 pressure equal to PA1, without the valve 11 presence λ would remain steady during all the modulation range; the valve 11 intervenes to modify λ following the input formulated by 15 according to the flame ratio detected by 14A, modifying in PGF1 the pressure upstream injector 23 therefore the fuel gas flow rate and consequently λ in the mixture, between a fixed minimum and maximum deviation, a flame ratio increase causing a λ decrease and vice versa, in order to maintain said flame distance around a pre-fixed optimum value.
In the ignition phase the valve 11 is completely open to maintain a λ value lower for a certain time.
FIG. 7 shows a natural draught combustion system which employs an atmospheric partially premixed burner 8A of the extractible type, lip shaped flame openings 7B (perpendicularly lengthened to the drawing) on burner head 6 and internal fluids dynamic obstacles with V shaped cross section, made from bimetallic sheets. Being the centre distance among exits 7B big, the flame, ignited by a device not seen, divides itself in long separate V shaped lamellar flames 19A (perpendicularly lengthened to the drawing). The process controller 15, upon signal of flame ratio from the temperature sensor 14C through step by step motor 25 varies the primary air flow as better described in FIG. 9.
Moreover a thermocouple 16 put on a flame opening lip 7B1 allows to maintain at the minimum the λ value in ignition until the lip temperature has not reached a value of let's say 150° C.
At the same time, as described in the enlarged section of a flame opening 7B of FIG. 8 the internal bimetallic sheet V shaped obstacle, according to the temperature reached changes the cross section of the opening 7B therefore changing the outflow velocity so to favour the stability. For higher temperatures (continuous line) smaller cross section, the contrary (dashed line) for lower temperatures.
In FIG. 9 is shown how the rotation of the eccentric axis 28 varies the primary air flow to the Venturi through 9A moving the sleeve sliding on the gas injector 23 to maintain steady the flame position with the λ variation as often described. Two positions of the sleeve regulating λ in the mixture are displayed: continuous line for maximum λ, dashed line for minimum λ.
In the combustion system of FIG. 10 the fan 4 is downstream the exchanger 2, the burner, with a Venturi tube 10A, is atmospheric totally premixed, (nevertheless passages for secondary air among the openings 7B can be provided). The flame openings 7B are lengthened, perpendicularly to the drawing surface, and made from lips obtained with the sheet of burner head 6. On the centre line axis of the flow from openings 7B, in combustion chamber 3, at a distance which can reach ten times the flame opening width are put V section fluids dynamics obstacles 12A with vertexes upstream which cause stagnation downstream having the dimension perpendicular to the axis of the same magnitude of the flame openings 7B width which, in this case, can be between 2 and 4 mm, while the lips height can vary from 10 to 20 mm; the obstacles have the same length of the flame openings perpendicularly to the drawing.
The flame 19, ignited by a device not seen, stays steadily anchored downstream the obstacles 12A becoming wave shaped carpet as the flame openings are close enough to each other. A variation of the heat request causes a change of the valve 11 opening, the fuel-gas flow rate is controlled by the warm wire sensor 29 which sends a signal to 15 to modify the eccentric axis 28 position driven by the step by step motor which moves the external obstacles 12A to modify the flame openings cross section 7B so as to maintain almost constant the velocity of the mixture outflow
At the same time the fan 4 spin velocity is modified by the process controller 15 according to the signal of the flame ratio detected by the optical sensor 14B so that the λ variation in the mixture maintains the flame distance at the best position as already described.
FIG. 11 is a view from A--A section of FIG. 10, the obstacles 12A balanced on the springs 30 pressed at the centre by the eccentric axis 28 which can move them, each other parallely in a vertical way to modify the cross section of the flame openings 7B of FIG. 10 as better seen in the section of FIG. 12 where these obstacles are in intermediate position (continuous line) and in reduced passage position (dashed line)
The same combustion system of FIG. 10, 11, if the case with unimportant changes, but using a different controll process with a different controller device can be regulated in this new way:
the signal of the fuel gas flow rate from the warm wire sensor 29 is worked out from the process controller to vary the value of λ according to the said flow rate by changing the fan spin velocity as well described previously.
the signal of flame ratio transmitted from the optical-sensor 14B is worked out from said controller to change the eccentric axis 28 position driven by the step by step motor 25 which moves the external obstacles 12A to vary the flame openings cross section 7B so as to modify the mixture outflow velocity to maintain the flame at the best position according to the flame ration variation law.
The movement of the external obstacles 12A is either upwards or downwards whether the flame ratio 19 rises or lowers itself, the movement can be gradual, or on-off, up to closing the flame openings according to the needs.
In FIG. 13 is shown a natural draft combustion system with partially premixed atmospheric burners of extractible type 8A; a spark ignition device 13 which at the start, ignite the mixture out flowing from flame opening of left burner to form a first V shaped lamellar flame 19A which cross-ignites the other burners 7B creating similar flames remaining separate. It is also shown, but more detailed in FIG. 14, how a temperature sensor 17A of the flame opening lips, which corresponds, in a reduced modulation range, to a flame distance sensor, can also be the actuator of the movement, capable of modifying the outflow cross section directly, as mobile part 7B2 of the flame opening which has fixed lips 7B1; in fact the two bimetallic sheets, which occupy longitudinally all the flame opening where they are mounted, are coupled together by longitudinal welding at the low edges so that, heating themselves the upper edges, symmetrically spread as regards to the central axis of the flame opening itself, as per dashed line in FIG. 14. These sheets at room temperature are pre-charged in order not to move away the upper edge until the temperature of same does not reach approx. 150° C.
In FIG. 15 is shown a forced draught combustion system with partially premixed atmospheric burner; and in more details in FIG. 16 is shown the temperature sensor 17B of the flame opening 7B, which is, in a limited range, equivalent to a sensor of the flame distance, is also actuator of the movement able to modify the outflow cross section directly, as mobile part 7B2 of the flame opening 7B, in this case is a sealed bulb seensor 17B, filled with a fluid, which expand at the temperature increase and shrinking at its decreasing, its upper lips 7B2 which are part of the flame opening 7B with fixed lips 7B1, makes outflow cross section of said openings directly change.
In fact the expansion or contraction of the fluid in the bulb can modify the transverse section of this to directly modify the outflow section. In FIG. 17 is shown a burner 8A with a sole flame 19A. In FIG. 18 the same burner is shown without the flame, the opening 7B having only two mobile lips 7B2, which define the outflow cross section of it, moved by the deformation (temperature function of the flame opening and therefore of the flame distance) of two bimetallic sensors-actuators 17A. The lips 7B2 position full line drawn and the dashed drawn one correspond to two different conditions of the flame opening temperature obviously higher the one corresponding to the dashed line. An external fluids dynamics V shaped obstacle positioned with the central axis on centerplane of the burner at a distance from the flame opening edges of 3 to 10 times the width of the flame opening with a cross dimension of the same magnitude of said width, anchors the large V shaped flame. FIG. 19 shows a cross section of a slightly different burner.
In FIG. 20 is shown a natural draught combustion system with atmospheric burner having a head 6 in perforated sheet metal the variation of the mixture temperature is realised according to the flame ratio, detected by a ionisation current sensor, able to detect the average value of the ionisation current, in three different positions using three electrodes on different levels and distance from the nearest flame opening, so that by any fuel gas flow rate, at least one electrode will detect the ionisation current upstream the flame front, a net made of parallel ceramic rods 22 in one direction and wires heating element perpendicularly, covering the combustion chamber plan said wires if under a predeterminated electrical tension are heated to a temperature around 1000° C.; therefore are capable of igniting the mixture. In case the wires are organised in more than one circuit, 20e1 and 20e2 acting also as part of the fluids dynamic obstacle, as shown in FIG. 21, after the ignition the variation of the mixture temperature, obtained upstream the flame front, can vary by steps; FIG. 21 shows an enlarged plan view of the burner head, slots parallel each other combined in groups of three and four, these said groups (the flame openings) are distributed in a check pattern to obtain a flying carpet shape lamellar flame 19 of FIG. 20. In FIG. 22 shows a pressurised combustion system I (the fan is upstream the combustion chamber 3), the heat request produces a variation of the fan 4 spin velocity, consequently a variation of the air pressure Pa=Pg means fuel gas low rate, mantaining λ constant at the changing of the instantaneous fuel-gas flow rate; the variation of the mixture temperature up stream the flame front 19 according to the flame ratio detected by the ionisation sensor 14A, which works as that of FIG. 20, worked out from the controller 15 changes the electric input to the heating element 20i which never reaches such temperatures to risk the ignition of the mixture inside the burner chamber 18; the wave carpet type flame pattern is obtained with a series of t-wings rows of slots forming openings 7B having obstacles 12C, the ignition device is not shown.
In FIG. 23 is shown a forced draught combustion system using an optical device to detect the flame ratio as to permit to the controller 15 the variation of the mixture temperature and of λ (as in FIG. 1,2,3) according to said flame ratio; the mixture is heated by a heating element 20i which acts also as fluids dynamics obstacle, V shaped, made of special steel sheet metal, punched as shown in FIG. 27, supported by a ceramic rod; the slots punched on the sheet metal head 6, organised in rows near each other, together with the V shaped obstacle produce carpet lamellar flame.
In FIG. 24 and 25 is shown a forced draught combustion system 1 with variation of the temperature and of the outflow velocity of the mixture according to the flame ratio; the mixture is heated by a heating element downstream the flame openings which also acts as fluids dynamics obstacle as in FIG. 23 moved up and down to vary the outflow velocity of the mixture as in FIG. 10, 11, 12 but using as control parameter the flame ratio as the temperature variation.
Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be obvious to those skilled in the art that certain changes and modifications may be praticed without departing from the spirit and scope thereof as described in the specification and as defined in the appended claims. | A combustion system includes a combustion chamber. A fan is connected to the combustion chamber. The fan has a spin velocity. A burner is adjacent the combustion chamber. The burner defines one or more flame openings. Each flame opening has a cross section. An obstacle is associated with each of the one or more flame openings. Each obstacle is within the combustion chamber. A mixture of fuel gas and air having a mixture temperature is discharged at a discharge velocity from the one or more flame openings. A flame is positioned along the burner substantially detached from the one or more openings. A flame position sensor senses the position of the flame and generates a flame position signal based on the sensed position of the flame. A control processor maintains the flame around a prefixed optimum position by controlling a characteristic variable quantity of the mixture based on the flame position signal. The characteristic variable quantity is selected from a premixture rate value of the mixture, the discharge velocity, and the mixture temperature upstream of the flame. The discharge velocity is modified by varying the cross section of the flame openings and the spin velocity of the fan. | 5 |
FIELD OF THE INVENTION
The present invention relates to an automatic, continuous method for printing multicolor-designs on a thermoadhesive or high-frequency (HF) weldable flocked film or substrate, to the film obtained by this printing method, as well to a method of application of this film onto a substrate to be decorated, such as a fabric, and consequently to the substrate printed according to this method.
BACKGROUND OF THE INVENTION
Printing by transfer-sublimation, i. e. by means of sublimable dyes, is already known, and it can be described as the printing, in a first step, of designs on a paper substrate by using inks constituted by sublimable dyes, capable of vaporizing when reaching a certain temperature and of fixing themselves permanently on certain synthetic fibers, whereas different methods can be used for printing the paper substrate, for instance offset, flexography- or heliography-printing, or flat-bed or rotary screen-printing. Then, in a second step, the pre-printed designs of sublimable dyes—as applied on the paper substrate—are transferred by contact under predetermined pressure and temperature between the printed paper and the fabric to be decorated.
This method of transfer-sublimation is currently used for printing on synthetic fabrics as well as on the surface of flocked fabrics which are commonly used for upholstery or automobile decoration.
However, this method has never been used for the printing of thermoadhesive or high-frequency-weldable flocked films, because the thermal sensitivity of such films makes it very difficult to print by transfer-sublimation, as this operation must be carried out at a minimum temperature of 180° C. (350° F.), which is a temperature that those films are unable to stand.
Furthermore, thermoadhesive or high-frequency-weldable films are commonly flocked with fibers made of rayon-viscose, which fibers cannot be printed satisfactorily by the existing method of transfer-sublimation.
Thermoadhesive or weldable flocked films are commonly used for the decoration of garments, fabric products and accessories, and more generally of all substrates suitable for decoration by means of heat-application or high-frequency (HF) welding.
Those thermoadhesive or weldable films are usually flocked with fibers which are dyed before flocking, which leads to one-color flocked surfaces in which patterns like numbers, letters or logos are cut out before being applied onto the substrate to be decorated.
For printing multicolored designs on a thermoadhesive or HF-weldable film, usually a screen-printing of a white-colored flocked film is carried out. Generally, white flock-fibers made of rayon-viscose are used. The thermoadhesive or HF-weldable flocked film which is screen-printed in this way with multicolor-designs is usually pre-cut before heat application in case of a thermoadhesive film, and cut out during application in case of HF-welding.
However, this screen-printing method presents some drawbacks, in particular a low washing fastness of the printed colors which are losing their brightness after several washings of the decorated substrate, as well as a low abrasion resistance of the rayon-viscose flock-fibers, mostly when being wet. Also the screen-printing of the flock-layer requires the deposit of an important amount of printing-ink in order to cover the full length of the fibers, which in its turn also requires the use of screens with open mesh, limiting therefore the accuracy of the printing and making impossible the reproduction in four colors and halftones, like for instance photographic works.
In order to obtain a HF-weldable multicolor flocked-film, the use of another method is known where different pre-died nylon flock-fibers are applied by “multicolor-flocking”, color by color, each fiber/color going through separate screens and being fixed onto a HF-weldable film, each screen being made according the position of each color in the final multicolor design to be printed on the film. However, this method requires the use of one separate screen for each printed color, and for each printed design, which makes this production of flocked sheets slow and technically difficult, and consequently expensive.
SUMMARY OF THE INVENTION
The present invention tends to remedy all above listed drawbacks by a new fully-automatic method of continuous printing of multicolor designs onto a thermoadhesive or HF-weldable film, allowing the reproduction of the finest possible details, including reproduction of four color and halftone photographic artworks, the final printing of the flock-fibers being of high washing-fastness and high abrasion-resistance.
In this purpose, the object of the present invention is a method for automatic continuous printing of multicolor designs on a thermoadhesive or HF-weldable flocked film, characterized by the fact that it comprises the steps consisting in:
applying an thermoadhesive or HF-weldable film onto a strippable protection paper.
applying an adhesive layer onto said film,
flocking white colored fibers or flocks onto the adhesive layer,
preparing a pre-printed paper with multicolor-designs constituted by sublimable color agents able to vaporize and fix themselves permanently on the said fibers, those pre-printed designs being exactly a reverse image of the designs to obtain on the flocked film,
transferring the multicolor-designs by sublimation from said pre-printed paper onto a laminate made of the protection paper and of the flocked film by contact under selected pressure and temperature.
The use of this strippable protection paper allows continuous printing of the thermoadhesive or HF-weldable flocked film without modifying this film's integrity and cohesion.
In a first embodiment, the temporary protection paper is coated or covered by co-extrusion with a film of synthetic polymers which are HF-weldable, such polymers being for instance resins of poly-vinyl-chloride (PVC), which can be used under compact form or foamed by use of chemical or mechanical swelling agents.
In a second embodiment, the temporary protection paper is coated or covered by co-extrusion with a film of synthetic resins which are thermoadhesive, such as hot-melt resins made with co-polyesters, co-polyamides, or resins of acrylic-esters, synthetic latexes, ethylene-vinylacetate (EVA), etc.
The fibers used for the flocking operation will advantageously be synthetic fibers, preferably fibers made from polyamide, such as nylon 6 or nylon 6—6 (trademark from DU-PONT DE NEMOURS), or even more preferably fibers made from polyester. For instance, fibers used will be fibers going from 0.5 mm (0.9 Dtex) to 2 mm (6 Dtex) or even longer.
Those fibers can also be either man-made-fibers, such as rayon-viscose, either natural fibers, such as cotton, which will be previously treated in order to be able to fix the sublimable dyes.
According to another characteristic, the transfer operation is made by means of a heat-printing calender, ensuring a uniform pressure generally lower than 40 kPa, between the pre-printed paper and the laminate, and a temperature comprised between about 180° C. (350° F.) and 230° C. (450° F.), during approximately 5 to 45 seconds.
Advantageously, the pre-printed paper is produced by printing the sublimable dyes onto the paper by means of an ink-jet printer, assisted by a computer system.
This is an important part of the present invention, as a direct printing of a flocked film is made very difficult with an ink-jet printer, the reason being the small amount of ink sprayed by such ink-jet printers which are unable to cover and fill totally the flock-layer in one run.
According to the present invention, the sublimable dyes are printed onto the paper by the ink-jet printer in one pass, which allows high-quality printing of any type of designs, including four color and halftone jobs, the use of an ink-jet printer with computer assistance being free of any printing tools, such as screens, engraved cylinders or plates.
An other object of the present invention is a flocked film, thermoadhesive or HF-weldable, obtained directly by the method as described here above, which comprises a strippable protection paper onto which a thermoadhesive or HF-weldable film is applied, said film being covered by an adhesive layer on which fibers or flocks printed with multicolored designs are sticking close.
An other object of the present invention is a method for the application of the above mentioned flocked film onto a substrate to be decorated, such as a fabric or any other substrate such as paper, cardboard, unwoven web or a plastic film, in which pre-selected designs to be applied onto the substrate are localized, those designs are then cut out on the film according to this localization, and the temporary protection paper is stripped off before application onto the substrate to be decorated, by means of heat-sealing or HF-welding, of the selected portion of the film which has been accordingly cut out and stripped off.
As a variant the method comprises the step, before localization of the printed designs, consisting in laminating the printed flock-fibers of the flocked film together with a temperature resistant substrate, which is slightly self-adhesive and which can resist to a temperature of 180° C. (350° F.), then cut out the film from its unflocked surface without cutting out the self-adhesive substrate, then strip off from the self-adhesive substrate the portion of the flocked film which does not correspond to the preselected designs, then the selected portions are indirectly applied onto the substrate to be decorated via the self-adhesive substrate and, finally, lift off the temporary substrate from the portions of the film which are thus applied onto the substrate to be decorated, after heat or HF-welding application.
Advantageously, in the case of HF-welding, the method comprises the step consisting in stripping off the temporary protection paper from the flocked film, in localizing the preselected designs on the flocked film, and using the welding tool for simultaneously cut out and HF-weld the thus localized portion of the flocked film on the substrate to be decorated, a layer of foam being possibly inserted between the flocked film and the substrate.
An other object of the present invention is a decorated substrate such as a fabric or any other substrate such as paper, cardboard, unwoven web or a plastic film, directly obtained by the method described here above, which comprises a substrate onto which is heat-mounted or HF-welded the portion of the heat-adhesive or HF-weldable film with the preselected and cut-out printed designs.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood and other aims, details, advantages and characteristics of the invention will appear more clearly from the below detailed description of a, at present, preferred embodiment of the invention, given only as an illustration and not limiting the invention, with reference to the enclosed drawings, on which:
FIG. 1 is a flat view per above of a laminated blank made with a temporary protection paper on which is applied a thermoadhesive film, coated on its upper side with an adhesive retaining white colored flocks;
FIG. 2 is a flat view per above of a pre-printed sheet of paper with reversed multicolor-designs;
FIG. 3 shows the opposite side of FIG. 2, and corresponds to the laminated blank shown in FIG. 1 after printing by transfer-sublimation of the multicolor designs pre-printed on the paper shown in FIG. 2;
FIG. 4 shows preselected multicolor-designs, cut out from the laminate shown in FIG. 3;
FIG. 5 shows the designs of FIG. 4, after the temporary protection paper has been stripped off;
FIG. 6 shows from above a piece of fabric on which the cut and stripped film portions of FIG. 5 have been heat-applied;
FIG. 7 is a cut view of the laminate shown in FIG. 3, on which a temporary self-adhesive paper has been applied.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
According the specific example shown on the enclosed drawings, the printing method described in present invention consists in coating firstly a base layer of a plastic material 2 forming a thermoadhesive or HF-weldable film on one side of a strippable protection paper sheet 1 (see FIG. 7 ).
This film 2 is coated on its opposite side with an adhesive layer 2 a on which fibers F, so called <<flocks>>, are flocked. FIG. 1 indicates as S the laminate constituted by temporary protection paper 1 , film 2 , adhesive layer 2 a and flock-fibers F, as seen from the side of the fibers F.
FIG. 2 shows a paper sheet 3 , pre-printed on a paper substrate with multicolor-designs M′ of sublimable dyes; pre-printing of the paper may be achieved for instance with an ink-jet printer assisted by computer (not shown in the Figures). This pre-printed paper 3 will be set up on a heat-printing calender (not shown) put in close contact with the flock-fibers F of the laminate S, made with temporary protection paper 1 and with flocked film 2 .
The laminate S is then advanced simultaneously with the rotation of the heat-printing calender under a uniform pressure, usually inferior to 40 kPa, and at a temperature comprised between 180° C. (350° F.) and 230° C. (450° F.), during approximately 5-45 seconds. It is in this way possible to obtain the transfer of the multicolor-designs M′ from the pre-printed paper onto the flock-fibers F by vaporization of the sublimable dyes which fix themselves permanently on the fibers of the flocked film. In FIG. 3, the laminate obtained after transfer-sublimation printing has been marked S′. This printing method brings the great advantage of printing the flocked film in a continuous way, the laminate S being unwinded in synchronization with the rotation of the heat-printing calender.
It should be noted that the printed flocked film S′, as shown in FIG. 3, offers printed designs M which are exactly the reverse “mirror” image of the designs M′ pre-printed on paper 3 as can be seen in FIG. 2 . Consequently, designs must always be printed on the paper 3 with the reverse image so as to obtain a design on the fabric to be decorated at this place.
In a first variant of the embodiment, the cutting out of certain selected designs 4 , printed on the laminate S′ shown in FIG. 3, is made directly in a continuous manner. This cutting operation can be carried out either with a die-cutting continuous machine, either by laser-cutter, either with a water-jet cutting device or with a computer controlled cutting-plotter. In order to make this cutting operation fully automatic, it is necessary to previously exactly localize the designs to cut out 4 , as indicated by the dot-line shown on laminate S′ in FIG. 3, which can be achieved by means of e. g. an optical localization equipment.
As shown in FIG. 5, the temporary protection paper 1 is stripped off in order to separate a portion of the printed flocked film 4 , corresponding to one or more cut designs M. Of course, the protection paper could in certain cases be stripped off before the cutting operation.
This portion of the printed flocked film 4 is then applied by its unflocked side onto a substrate 5 , for instance a garment or a fabric accessory or similar. The application is obtained by means of heat in order to fix the thermoadhesive film onto the fabric, which can be done with an electrically heated calender, a smoothing iron or similar heating equipment.
In an other variant of the embodiment, the flocked surface of the printed flocked film is laminated by means of pressure onto a slightly self-adhesive temporary substrate 6 having a high resistance to temperature as for instance a polyester film coated with special silicon-or acryhc-resins. The protection paper 1 is then stripped off and the flocked printed film is cut from its unflocked side 2 without cutting through the self-adhesive substrate 6 which is stuck on the upper side of the flock-fibers F of the flocked film. Due to the length of the flock-fibers, it is easy to limit the cut only to the flocked film.
In this variant, it is of course also possible to proceed to the cutting of the flocked film after optical localization of the printed designs, by transparency through the base film 2 of the flocked film.
Then the cut portion of the flocked film which is not printed and that must not be applied is stripped away from the self-adhesive substrate 6 . This temporary self-adhesive substrate presents the advantage that it maintains exactly the relative positions of the different selected designs 4 , without making necessary their re-positioning during their application onto the fabric to be decorated. Actually, those selected and cut printed designs 4 may be applied onto the fabric 5 while being still supported by the self-adhesive substrate 6 . During heat application onto the temporary substrate, the heat is indirectly transferred to the flocked film and melts the thermoadhesive part of the flocked film and sticks to the film, without alteration of the self-adhesive substrate which is apt to stand the temperature at thermal adhesion of the film.
After heat application onto the fabric to be decorated, the temporary substrate 6 is simply removed.
In the case of a HF-weldable flocked film, operations of cutting and application may be carried out simultaneously on the fabric to be decorated. A welding-electrode (not shown) is used for this purpose, which is at the same time a welding- and a cutting-tool sending HF-waves able to simultaneously cut out the selected designs on the flocked film and the border of these designs on the fabric to be decorated. It is also possible to insert a layer of PVC-foam between the fabric and the unflocked side of the flocked film. Obviously, the temporary protection paper will have been stripped off before.
This will result in a fabric decorated by a flocked film showing multicolor-printed designs, with a nice feeling and a soft touch. It is therefore more convenient to use flock-fibers with small diameter and a relatively important length.
Although the present invention has been described in connection with specific embodiments, it is obvious that it is not limited to those embodiments and that it also includes all technical equivalents of the described means, as well as their combining, whenever they enter in the field of the invention. | The method consists in applying a thermoadhesive or HF-weldable film ( 2 ) on a temporary protection paper ( 1 ), applying an adhesive layer 2 a ) on said film, flocking fibers (F) on this adhesive layer, preparing a pre-printed paper with multicolor designs constituted by sublimable dyes and transferring by sublimation the multicolor-designs from the pre-printed paper onto the flock-fibers by close contact between the two elements under a predetermined pressure and temperature. | 1 |
RELATED APPLICATION
This is a division of U.S. patent application Ser. No. 750,268 filed Dec. 13, 1976, now U.S. Pat. No. 4,133,000.
BACKGROUND OF THE INVENTION
This invention relates to a monolithic integrated circuit device having input circuitry protection integral therewith. More particularly it relates to a monolithic integrated circuit chip that includes an input resistor capable of absorbing surges of hundreds of volts.
It is known that input portions of integrated circuits may require protection from voltage surges. It is not unusual to want to include electrical components to provide such protection. If the voltage surges are fairly low, one can easily include planar-type components on the chip to absorb them. However, if the voltage surges are quite high, in excess of 50 volts, such components are not adequate.
It is not practical to include a high power zener diode on an integrated circuit chip. As a result, high voltage surge protection is conventionally not provided on the chip itself. It is normally provided in the connected external circuitry. If such protection could be provided on the chip itself, with components compatible with regular integrated circuit processing, one could increase reliability and decrease cost. An ancillary benefit, of course, is reduced size, weight and complexity of overall circuitry required.
No monolithic integrated circuit is currently available that has integral input circuitry protection capable of handling hundreds of volts. It is particularly desirable to provide such protection in automotive electrical systems, where transients of several hundreds volts are known to occur. A monolithic integrated circuit having integral input circuit protection capable of absorbing such transients may even permit such circuits to be more readily included in wiring harnesses, harness connectors and the like. This could simplify overall circuitry, lower its costs, and increase its reliability.
OBJECTS AND SUMMARY OF THE INVENTION
It is, therefore, an object of this invention to provide a monolithic integrated circuit that includes means in series with input circuitry that is capable of absorbing hundreds of volts.
It is also an object of this invention to provide a high voltage surge protection resistor in an integrated circuit structure that can be made by conventional integrated circuit processes.
A further object of this invention is to provide a method of making such products.
These and other objects of the invention are attained with a thermally grown silicon dioxide layer covering the silicon surface of an integrated circuit chip. A minor area of the layer has a significantly greater thickness than the maximum thickness of the silicon dioxide layer on the balance of the chip. The minor area thus forms a plateau of thermally grown silicon dioxide on the chip surface. A high value polycrystalline silicon resistor is disposed on the plateau, along with means, a contact pad for connecting it to the external circuitry subject to voltage surges. The contact pad is connected to one end of the resistor, and a conductor lead to chip input circuitry is connected to the other end of the resistor. The structure is compatible with integrated circuit processing in that it can be made without changing conventional integrated circuit process steps. One merely adds the steps of plateau and polycrystalline resistor formation at selected points in the otherwise conventional process.
BRIEF DESCRIPTION OF THE DRAWING
Other objects, features and advantages of the invention will become more fully appreciated from the following description of preferred embodiments and from the drawing, in which:
FIG. 1 shows an electrical schematic of an input portion of an integrated circuit chip made in accordance with this invention;
FIG. 2 shows a fragmentary plan view with parts broken away of one corner of a monolithic integrated circuit chip after a thick silicon dioxide island is formed thereon;
FIG. 3 shows a plan view of the chip portion of FIG. 2, with parts broken away, after electrical components are formed on the plateau and in the chip; and
FIG. 4 shows a sectional view along the line 4--4 of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows an electrical schematic of the electrical components contained in the portion of the monolithic integrated circuit chip illustrated in FIGS. 3 and 4. The schematic in FIG. 1 shows a chip input contact pad 12 connected at 12a to one end to a surge protection resistor 14 that is labelled SPR. The surge protection resistor 14 has a resistance value in excess of 50 kilo-ohms. The other end of the surge protection resistor 14 is connected to 16a to conductor 16. Conductor 16 is, in turn, connected through conductor extensions 16b and 16c to the bases 18 and 20 of P-N-P transistors Q1 and Q2, respectively. Collector 22 of transistor Q1 is connected to conductor 16 through conductor extensions 16d. Thus, the base-collector junction of transistor Q1 is electrically shorted, so that transistor Q1 functions as a diode, and the collector of transistor Q1 is electrically in parallel with both transistor bases.
Emitters 24 and 26 of transistors Q1 and Q2, respectively, are electrically in parallel by means of a conductive path 28a and 28. The path has an extension 28b which leads to associated circuitry, as for example another chip contact pad for connection to a regulated power supply. Collector 30 of transistor Q2 is connected to a conductor 32 which has an extension portion 32a that leads to associated on-chip circuitry (not shown).
The electrical circuit portion illustrated in FIG. 1 is uniquely incorporated in a monolithic integrated circuit portion, as shown in FIGS. 2-4. Since this invention involves only a small portion of a silicon chip 34, FIGS. 2-4 show that portion in enlarged fragmentary views, to focus on the invention and show it more clearly. FIG. 2 shows the same portion of the silicon chip 34 illustrated in FIGS. 3 and 4 but in an intermediate phase of its manufacture. In the intermediate phase shown in FIG. 2, chip 34 has an isolation diffusion therein at portions 36 that defines N-type pockets 38, 40, 42 and 44. No device diffusions have yet been made. Chip 34 has a thermally grown silicon dioxide island 48a' thereon that is at least about 10,000 angstroms thick at this stage in chip processing. Due to further processing this thickness will increase to about 12,000-15,000 angstroms. The periphery of island 48a' is substantially coextensive with underlying pocket 38. Chip 34 is shown after the island 48a' has been defined by etching and etching maskant removed. The balance of surface 46 has no silicon dioxide coating on it at this stage of chip manufacture. Silicon dioxide is then thermally regrown on the uncovered portions of surface 46. Island 48a' becomes plateau 48a. A polycrystalline resistor 14' is later formed on plateau 48a after further processing.
FIGS. 3 and 4 show chip 34 after manufacture is completed. They show silicon chip 34 as containing an integrated circuit of diffused resistors and bipolar components interconnected by an overlying metallization. It is referred to herein as a monolithic integrated circuit of the bipolar type. Components in the balance of the chip surface (not shown) would be made in the same manner as those which are shown. Also, for added clarity, the silicon dioxide layer on chip 34 is considered transparent in FIG. 3 to better show underlying diffusion regions. Also for clarity thickness variation and surface contours are also omitted in FIG. 3.
Silicon chip 34 is a rectangular body of 10-20 ohm centimeter P-type silicon about 10 mils thick having a 0.4 mil thick epitaxial layer of 0.5-2 ohm centimeter N-type silicon thereon. Wafer and epitaxial layer thickness are not limited by this invention. Any thickness can be used that is satisfactory for the integrated circuit being made. The normal and accepted criteria for wafer and epitaxial layer thickness in a conventional integrated circuit can be used in this invention.
A P-type isolation diffusion through selected portions 36 of the epitaxial layer forms a plurality of N-type pockets in the epitaxial layer, including L-shaped pocket 38 and rectangular pocket 40. Additional N-type pockets 42 and 44 are only partially shown. The entire surface 46 of chip 34 is covered with a thermally grown silicon dioxide layer 48. A portion 48a of this silicon dioxide layer is substantially coextensive with the chip surface 46 over pocket 38 and has a thickness of at least about 10,000 angstroms, preferably about 12,000-15,000. All other portions 48b of this silicon dioxide layer have a significantly lesser thickness of about 2,000 to 8,000 angstroms. For example, pockets 40, 42 and 44 and all other pockets on the chip having components formed therein by diffusion will have a thermally grown silicon dioxide layer 48b of less than 8,000 angstroms. The significantly thicker portion 48a thus forms a plateau in silicon dioxide layer 48, and corresponds to the island 48a shown in FIG. 2.
All of the N-type pockets in chip 34 have surface diffusion regions therein forming electrical components for the monolithic integrated circuit. Two lateral P-N-P transistors are formed in pocket 40 in a concentric pattern. N-type pocket 40 contains two rectangular generally ring-like P-type regions 22' and 30' inset therein. Each of regions 22' and 30' have one side widened at 22a' and 30a', respectively, to facilitate making electrical connections to them. Regions 22' and 30', respectively, form the collector 22 and collector 30 of transistors Q1 and Q2. Island-like P-type regions 24' and 26' are inset within and inwardly spaced from the inner periphery of ring-like regions 22' and 30', respectively. They respectively serve as emitters 24 and 26 for transistors Q1 and Q2. Pocket 40 thus serves as a base region common to both of transistors Q1 and Q2. Pocket 40 contains an L-shaped N+ region 50 inset therein beneath conductor extensions 16b and 16c for making an ohmic contact to pocket 40. The part 18' of pocket 40 between regions 22' and 24' thus serves as a base region for transistor Q1. Analogously, the part 20' of pocket 40 between regions 26' and 30' serves as a base region for transistor Q2. All of these regions in the pockets are formed by diffusion into the pocket through surface 46, and are covered with a thinner thermally grown silicon dioxide coating 48b. A buried N+ layer 62 is beneath pocket 40, to facilitate lateral transistor action of transistors Q1 and Q2.
Plateau 48a of the thermally grown silicon dioxide has a surge protection resistor 14' labelled SPR thereon in the form of a coating about 0.8 micron to 1.2 micron thick of polycrystalline silicon. The polycrystalline silicon coating has a sheet resistance of at least about 10 kilo-ohms per square, preferably 10-20 kilo-ohms per square and is about 8,000-12,000 angstroms thick. It is in an elongated pattern defining a surge protection resistor 14' with a value of at least about 50 kilo-ohms, preferably 100 kilo-ohms. One end of the resistor 14' is overlapped by an extension 12a' of an evaporated aluminum input contact 12'. Like resistor 14', contact 12' is disposed entirely on plateau 48a of the silicon dioxide layer. The other end of surge protection resistor 14' is overlapped by portion 16a' of an evaporated aluminum conductor 16'. The second and third extensions 16b' and 16c' of conductor 16' cover the N+ region 50, and make ohmic contact to pocket 40. A fourth extension 16d' of conductor 16 makes ohmic contact with side 22a' of the collector region 22' of transistor Q1.
Evaporated aluminum conductors 16b' and 16c' communicate with region 50 of pocket 40 through an L-shaped aperture 52 in the overlying thinner portion 48b of the silicon dioxide layer. Analogously, extension 16d contacts collector region 22' through an aperture 54 in the thin portion 48b. An evaporated aluminum conductor segment 32' contacts collector region 30' through an aperture 56 in the thin oxide 48b. It has an extension 32a' leading to other circuitry on the chip, such as another transistor region 58 in pocket 42 or diffused resistor 60 in pocket 44. An evaporated aluminum conductor segment 28a' and 28' contacts emitter regions 24' and 26', respectively, through apertures (not shown) in the interjacent thin oxide 48b. An extension 28b' leads to other portions of the chip, as for example a contact pad for connection to a regulated voltage source.
As previously noted, plateau 48a of the silicon dioxide layer 48 is significantly thicker than other portions 48b covering other parts of chip surface 46. If greater than about 10,000 angstroms, it can withstand hundreds of volts without dielectric breakdown between pocket 38 and the overlying surge protection resistor 14'. If no electrical components are formed in pocket 38, field effects in pocket 38 due to voltage surges cannot produce circuit abnormalities of any kind. Surges of hundreds of volts applied to input contact 12' can be readily absorbed by the surge protection resistor 14' without deleterious affects.
The foregoing structure can be made by a conventional integrated circuit process to which plateau and resistor formation steps are added. The initial thickness of plateau 48a is formed by extended oxidation of the silicon surface prior to the isolation diffusion. It is the only portion of the thermally grown silicon dioxide coating retained intact during the remainder of processing. The configuration of the diffusion regions forming integrated circuit components in other wafer portions, as well as the manner of making such diffusions, is not material to this invention. Any wafer or region resistivity, configuration, and diffusion technique one would otherwise employ, if this invention were not incorporated in the chip, can be used. No change in any of such diffusions is required to make them compatible with this invention. It is inherently compatible with whatever specific integrated circuit process is desired.
To illustrate this compatibility is the following description of one such process. A 10-20 ohm centimeter P-type silicon wafer is used that is large enough to contain a plurality of integrated circuit chips simultaneously formed therein. An N+ region 62 is diffused into a selected part of each chip area that is to lie beneath pocket 40 when it is formed. Then a 1-2 ohm centimeter N-type silicon layer is epitaxially deposited onto the wafer, burying the N+ region. The epitaxial layer is about 0.4 mils thick and the wafer is about 10 mils thick. The wafer is then oxidized to a thickness of at least about 8,000 angstroms, preferably 10,000 angstroms and photolithographically masked. Any of the normal and accepted techniques for producing a thick, adherent, dense and pin-hole free layer of thermally grown silicon dioxide can be used. For example, the wafer can be heated to a temperature of approximately 1100° C. in wet oxygen for about 100 minutes. It is etched in buffered hydrofluoric acid to remove the silicon dioxide from selected surface areas, to produce a mask for diffusion of the isolation walls 36 through the epitaxial layer. A P-type impurity such as boron is then diffused into the exposed surface areas to form the isolation walls 36, and divide the epitaxial layers into a plurality of PN junction isolated N-type pockets, such as 38, 40 and 42. It is conventional to regrow silicon dioxide on the previously exposed wafer surface areas during drive-in of the P-type impurity, to protect the wafer surface 46. The regrown silicon dioxide over the isolation diffusion regions is about 4000-6000 angstroms thick.
A portion 48a' of the silicon dioxide coating is then selectively covered with a photoresist. This portion is in register with N-type pocket 38. The wafer is then etched in buffered hydrofluoric acid to strip all of the exposed original and regrown thermal oxide not covered by the photoresist. This leaves an island 48a' of silicon dioxide over and coextensive with N-type pocket 38. A layer of about 4,000-6,000 angstroms of silicon dioxide is then thermally regrown on the wafer surface areas from which it was just removed. The island portion increases in thickness during this step. It is about 10,000 angstroms or more in thickness at this point, and forms a plateau 48a with respect to the reformed silicon dioxide 48b on other portions of wafer surface 46.
The wafer is then photolithographically masked and etched in hydrofluoric acid to re-expose the isolation diffusion regions and to open windows over regions where a shallower P-type diffusion is desired for masking the transistor region. This diffusion is referred to as the base diffusion for vertical N-P-N transistors. The isolation diffusion regions are exposed in this step, as usual, to reinforce surface doping. A P-type impurity such as boron is then diffused through the openings in the silicon dioxide and, as described before, a silicon dioxide coating is regrown in these openings during drive-in of the boron. The wafer is then photolithographically masked and etched again in buffered hydrofluoric acid to expose wafer surface areas covered by only the thin silicon dioxide layer where a low resistance contact region, or an emitter in an vertical N-P-N transistor is desired. Phorphorus is diffused into these regions and a silicon dioxide layer concurrently regrown in the openings. At this point, the entire surface of the wafer is covered with a thermally grown silicon dioxide layer. In plateau area 48a, the silicon dioxide layer is preferably greater than 12,000 angstroms and of uniform thickness. In other areas 48b, it is of non-uniform thickness, and is less than about 8,000 angstroms.
A polycrystalline silicon coating is then deposited onto plateau 48a. The particular manner of depositing the polycrystalline silicon is not significant so long as it produces a resistive coating on plateau 48a of the desired sheet resistance. The polycrystalline silicon can be applied by sputtering, vacuum deposition or chemical vapor phase deposition. I prefer to use thermal decomposition of silane, with argon as the carrier gas, to deposit the polycrystalline silicon layer. Boron ion implanation can be used to precisely adjust the polycrystalline silicon to a specifically desired sheet resistance after it is deposited. The resistor pattern can be defined in any convenient manner. I prefer to deposit a blanket coating onto the entire surface and selectively etch unwanted portions of the blanket coating away. It can be plasma etched or etched in a wet chemical technique. The etch used is not important. For wet chemical etching a silicon dioxide layer is usually required on top of the polysilicon to act as a mask.
Contact windows are then opened in the thin oxide portions 48b on wafer surface 46 using photolithography techniques. A blanket deposition of aluminum is made and unwanted portions etched away to form the conductors such as 16', 28' and 32', and the contact pads such as 12'. Scratch protection is obtained by depositing a blanket coating of a low temperature phosphorus doped glass or its equivalent onto the entire chip surface. Windows over the contact pads are then opened in this latter coating using photolithography, so the contact pads are exposed for bonding.
The foregoing description shows how this invention is incorporated in a bipolar integrated circuit. It can also be readily incorporated in an integrated circuit of field effect devices, including silicon gate metal-insulator-semiconductor devices. Further, plateau 48a was described as being formed before the isolation diffusion, which is preferred. However, it can also be formed between the isolation diffusion and the base diffusion steps. | A monolithic integrated circuit structure having an integral high value surge protection resistor of polycrystalline silicon on a thermally grown thick silicon dioxide plateau having no surface diffusion regions thereunder. The structure can be made by merely adding intermediate steps to existing integrated circuit processing. It is capable of absorbing transients of hundreds of volts. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to a bushing base plate having a box filled with melted glass or a nozzle aperture of a bushing employed for preparing glass fibers or continuous glass filaments.
Several plates are currently employed as a bushing base plate. Generally, the bush base plate is prepared by conducting a perforation treatment of a bashing base raw plate and inserting a hollow tube processed in advance to the shape of a pipe into the aperture of the raw plate and bonded by means of welding. Another bushing base plate which is prepared by compressing raw material having a plate thickness thicker than that of a final product by means of rolling or pressing to extrude a projection, and thereafter conducting a perforation treatment to the extruded projection by means of pressing is also employed.
A glass fiber of thin denier and an effective production thereof by making many holes in a certain area with smaller pitches are demanded and a bushing base plate satisfying these requirements is highly requested.
When conventionally welding is conducted by making an aperture through the bushing base raw plate and inserting the hollow tube processed in advance to the shape of a pipe into the aperture of the raw plate, the bushing base raw plate 1 and the hollow tube 3 having a flow-out aperture 2 are as shown in FIG. 1 are welded at the base end of the hollow tube 3 by means of razor or plasma or resistive welding.
In this case, the hollow tube 3 in the shape of a pipe is finished so as to have a thin wall due to the spinning conditions of glass fibers. When the hollow tube is welded to the position perforated through the bushing base raw plate 1, the welding is performed at the base end 3a of the hollow tube 3 that is the flow-in side of the glass as shown in FIG. 1.
Since the wall thickness of the hollow tube 3 is thinner than the thickness of the bushing base raw plate 1, the size of the flow-out aperture is small and the pitch between two adjacent flow-out apertures is small so that the whole thickness of the bushing base raw plate 1 is difficult to be welded, only an upper portion of the raw plate 1 is welded as shown in FIG. 1. Because of this partial welding, the flow-out aperture is difficult to be processed to the shape which fits the flow conditions of glass or the spinning conditions.
When the thus manufactured bushing case plate 4 is employed successively for a long period of time at a high temperature, a creep strain is produced in the bushing base plate 4 receiving a pressure P of glass to be entirely deformed so as to have a swelling as shown in FIG. 2.
FIG. 3 is an enlarged view showing the above fitting portion of the hollow tube 3. Due to the creep deformation of the bushing base raw plate 1, a space is formed between the raw plate 1 and the hollow tube 3 to produce a crack at the above welded portion so that a drawback of enabling the glass fiber spinning because of the leakage of glass liquid. In the worst case, the hollow tube 3 may fall off.
This drawback is critical because even when only one of the flow-out apertures is cracked or falls off, an expensive Pt alloy bushing can be no longer employed so as to stop the production or the bushing with the defect may largely influence the quality and the cost of the glass fibers. It is a problem to be solved how to provide a bushing in which cracking and the falling off are difficult to occur.
A new process of preparing a bushing is proposed in Japanese laid open gazette No. 4-241105 or the like. This contemplates to perform the bonding employed Pt waxy material to the Pt alloy base plate. When a small amount of an element is added to Pt in case of a Pt--Au alloy or a reinforced alloy, that is, when the material possesses a melting point which is the same as or smaller than that of Pt as waxy material, it is supposed to be difficult to melt the Pt by employing Pt as the waxy material.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a bushing base plate having stabilized bonding strength and a shape suitably fitted to spinning conditions so as to possess a long life and a process of preparing same.
A first invention in accordance with the present invention is a bushing base plate comprising a bushing base raw plate having a circular or irregular aperture and a hollow tube having an outer diameter portion larger than the inner diameter of the aperture which is inserted into the aperture at a certain interference and fixed to the bushing base raw plate, that are bonded by means of thermal diffusion.
Another embodiment of the first invention is a bushing base plate comprising a bushing base raw plate having a circular or irregular aperture and a hollow tubular swelling integrally connected to one end of the aperture wall, and a hollow tube having an outer diameter portion larger than the inner diameter of the aperture which is inserted into the aperture at a certain interference and fixed to the bushing base raw plate, that are bonded by means of thermal diffusion. The material of the hollow tube employed herein may be different from that of the bushing base raw plate.
The hollow tube or pipe is in advance processed to suitably possess designated product dimensions by means of an extrusion processing, a press processing or the like or may be processed to dimensions slightly higher or lower than the designated dimensions. The outer shape of the hollow tube is suitable for being inserted into the aperture with a certain interference. The hollow tube is inserted into the aperture and fixed to the bushing base raw plate by means of thermal diffusion treatment.
A second invention in accordance with the present invention is a process of preparing a bushing base plate which comprises rolling bushing base plate material to a flat bushing base raw plate having a thickness the same as that of a product, forming a required number of one or more circular or irregular apertures through the flat bushing base raw plate, inserting a hollow tube into the aperture at a certain interference for fixing the hollow tube to the bushing base raw plate, or inserting the said hollow tube and enlarging the hollow tube from the inside to have a desired interference, and bonding the both by means of thermal diffusion.
Another embodiment of the second invention is a process of preparing a bushing base plate which comprises perforating a circular or irregular aperture at the center of a swelling which is formed simultaneously with or before the formation of the said aperture through a bushing base raw plate, inserting a hollow tube into the aperture at a certain interference for fixing the hollow tube to the bushing base raw material, or inserting the said hollow tube and enlarging the hollow tube from the inside to have a desired interference, and bonding the both by means of thermal diffusion. Depending on the case, the bonded hollow tube and the swelling may be molded by means of plastic deformation to have a desired shape and desired dimensions. The material of the hollow tube employed herein may be different from that of the bushing base raw plate.
The hollow tube or pipe is in advance processed to suitably possess designated product dimensions by means of an extrusion processing, a press processing or the like or may be processed to dimensions slightly higher or lower than the designated dimensions. The outer shape of the hollow tube is suitable for being inserted into and fixed to the aperture with a certain interference. The hollow tube is inserted into the aperture and fixed to the bushing base raw plate by means of thermal diffusion treatment.
A third invention in accordance with the present invention is a bushing base plate comprising a bushing base raw plate having a circular or irregular aperture of which an aperture size of its glass flow-in side is larger than that of a glass flow-out side, and a hollow tube having a glass flow-out end of which an outer size is the same as or smaller than the above aperture size of the glass flow-in side and a glass flow-in end of which an outer size is the same as or larger than the above aperture size of the glass flow-out side and having a circular section when the aperture of the bushing base raw plate is circular or an irregular section when the aperture of the bushing base raw plate is irregular, the hollow tube being inserted into the aperture of the raw plate and fixed thereto by means of thermal diffusion.
Another embodiment of the third invention is a bushing base plate which comprising a bushing base raw plate having a circular or irregular tapered or rounded aperture of which an aperture size of its upper (glass flow-in) side is larger than that of a glass flow-out side, and a hollow tube having a tapered or rounded glass flow-in end of which an outer size is larger than the above aperture size of the glass flow-out side and having a circular section when the aperture of the bushing base raw plate is circular or an irregular section when the aperture of the bushing base raw plate is irregular, the portion from the upper end of the tapered or rounded aperture to the lower end thereof of the hollow tube being tightly inserted into the wall of the aperture of the raw plate and fixed thereto by means of thermal diffusion.
The aperture of the bushing base raw plate and the hollow tube may have two or more tapered or rounded portions or two or more steps and the combination of a tapered portion and a rounded portion may be employed in addition to one tapered or rounded portion.
If one tapered portion is present, its tapered angle is preferably between 0.1 and 120°, while if two or more tapered portions are present, the tapered angle of at least one of the said tapered portion is preferably between 0.1 and 120°.
The hollow tube may be coated with base plate raw plate material at the glass flow-out side of the bushing base raw plate for a certain length for reinforcement.
The bushing base plate may be molded to have the tapered or rounded shape at the periphery including the bonding boundary of the glass flow-in side and/or glass flow-out side.
As the above hollow tube, a tube is employed having an inner circular section and an outer circular section.
As the above hollow tube, a tube is also employed having an inner irregular section and an outer irregular section.
As material of the above bushing base raw plate, a Pt--Rh alloy, a Pt--Rh--Pd alloy, platinum of which grains are stabilized by an oxide, an platinum alloy of which grains are stabilized by an oxide, a Pt--Au alloy, a Pt--Rh--Au alloy or a Pt--Rh--Pd--Au alloy may be employed, and material of the hollow tube, a Pt--Au alloy, a Pt--Rh--Au alloy, a Pt--Rh alloy, a Pt--Rh--Pd alloy, platinum of which grains are stabilized by an oxide or an platinum alloy or which grains are stabilized by an oxide may be employed.
A fourth invention in accordance with the present invention is a process of preparing a bushing base plate in accordance with the present invention comprises a process of preparing a bushing base plate which comprises perforating through a bushing base raw plate an aperture having a circular or irregular section of which an aperture size of its glass flow-in side is larger than that of a glass flow-out side, inserting and fixing to the aperture a hollow tube having a glass flow-out end of which an outer size is the same as or smaller than the above aperture size of the glass flow-in side and a glass flow-in end of which an outer size if larger than the above aperture size of the glass flow-out side and having a circular section when the aperture of the bushing base raw plate is circular or an irregular section when the aperture of the bushing base raw plate is irregular, and performing thermal diffusion for bonding.
Another embodiment of the fourth invention is a process of preparing a bushing base plate which comprises perforating through a bushing base raw plate a tapered or rounded aperture having a circular or irregular section of which an aperture size of its glass flow-in side is larger than that of a glass flow-out side, inserting from the glass flow-in side to the glass flow-out and fixing to the said aperture a hollow tube having a tapered or rounded upper (glass flow-in) end of which an outer size if larger than the above aperture size of the glass flow-out side and having a circular section when the aperture of the bushing base raw plate is circular or an irregular section when the aperture of the bushing base raw plate is irregular so as to tightly adhere the portion from the tapered or rounded upper end to the lower end thereof of the hollow tube to the whole wall or glass flow-out side wall of the aperture, and performing thermal diffusion for bonding.
When the aperture is perforated through the bushing base raw plate in this process of preparing the bushing base plate, a swelling portion surrounding the glass flow-out end of the aperture of the bushing base raw plate may be provided, and the hollow tube may be inserted into and fixed to the swelling portion and be bonded by means of thermal diffusion.
The bushing base plate may be prepared in accordance with the present invention by plastically deforming the bonding boundary of the glass flow-in side and/or the glass flow-out side to the tapered or rounded shape after the hollow tube is bonded to the aperture formed through the bushing base plate by means of thermal diffusion.
The bushing base plate may be prepared in accordance with the present invention by finishing the shape of the flow-out aperture to a desired shape and desired dimensions by means of the plastic deformation after the hollow tube is bonded to the aperture formed through the bushing base plate by means of thermal diffusion.
In this process of preparing the bushing base plate, after the hollow tube is bonded to the aperture formed through the bushing base plate by means of thermal diffusion and the plastic deformation is conducted, one or ore thermal diffusions may be repeated. The thermal diffusion may be conducted not only after the completion of the plastic deformation but also in the course of the plastic processing.
The thermal diffusion is preferably conducted in a temperature range between 500° C. and a temperature 20° C. lower than a melting point of the material.
As mentioned, the bushing base plate of the first invention enables the stable spinning by obtaining a structure in which end breakage is difficult to occur in the spinning generated at a center of densely distributed apertures because neither space nor is present in the bonding portion, the strength of the resulting bushing base plate is the same as that of the mother material to be endured by an operation for a long period of time and the material difficult to be wetted may be employed as the end chip portion.
According to the process of preparing the bushing base plate of the second invention, a bushing may be obtained which possesses a stable strength and a long life containing a bushing base plate having a plurality of apertures with a small diameter and narrow pitches. Since the wall thickness of the nozzle is thin, densely distributed apertures may be easily mechanically processed without skill, neither space nor is present in the bonding portion, the strength of the resulting bushing base plate is the same as that of the mother material to be endured by an operation for a long period of time and the material difficult to be wetted may be employed as the end chip portion, an apparatus of spinning glass fibers capable of performing stable spinning may be obtained by realizing a structure in which end breakage generated at the center of the densely distributed apertures is difficult to occur during the spinning.
According to the bushing base plate and the process of preparing same of the third and fourth invention, the bushing can be obtained which enables to the manufacture of uniform glass fibers having a high precision. Even if the deformation of the bushing base plate is produced due to the creep deformation produced by the pressure of glass and a high temperature exposed for a long period of time during the spinning, no space is created between the hollow tube and the bushing base raw plate bonded to each other constituting the glass flow-out aperture so that the crack formation at the welded portion and the falling-off of the hollow tube never occur. Accordingly, the above bushing is safely employed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing one conventional example of the bonding portion between an aperture of a bushing base plate and a hollow tube.
FIG. 2 is a sectional view showing another modified embodiment of the bushing base plate.
FIG. 3 is a sectional view showing a space in the bonding portion between an aperture of a conventional bushing base plate and a hollow tube.
FIG. 4 is a sectional view showing an aperture of a bushing base raw plate of Example 1.
FIG. 5 is a sectional view showing a hollow tube of Example 1.
FIG. 6 is a sectional view showing the bonding portion between the aperture of the bushing base plate and the hollow tube.
FIG. 7 is a sectional view showing a bushing base raw plate having a swelling of Example 2.
FIG. 8 is a sectional view showing the bonding portion between the swelling of the raw plate and the hollow tube of FIG. 7.
FIG. 9 is a sectional view showing a bushing base plate of Example 3 prepared by further modifying the bushing base plate of FIG. 8.
FIG. 10 is a sectional view showing the bonding portion between an aperture of a conventional bushing base plate and a hollow tube of another embodiment of Example 3.
FIG. 11 is a sectional view showing the bonding portion between an aperture of a conventional bushing base plate and a hollow tube of a further embodiment of Example 3.
FIG. 12 is a sectional view showing a bushing base raw plate having an aperture employed in Example 6.
FIG. 13 is a sectional view showing one example of a hollow tube employed in Example 6.
FIG. 14 is a sectional view showing one step of a preparing process of Example 6.
FIG. 15 is a sectional view showing another step in Example 6.
FIG. 16 is a sectional view showing a further step in Example 6.
FIG. 17 is a sectional view showing a hollow tube employed in Example 7.
FIG. 18 is a sectional view showing the hollow tube and a raw plate combined with each other of FIG. 17.
FIG. 19 is a sectional view showing a bushing base raw plate employed in Example 8.
FIG. 20 is a sectional view showing the hollow tube and a raw plate combined with each other of FIG. 19.
FIG. 21 is a sectional view showing an alternative embodiment of FIG. 20.
FIG. 22 is a sectional view showing a bushing base plate of Example 9.
FIG. 23 is a sectional view showing a bushing base plate of Example 10.
FIG. 24 is a sectional view showing an alternative embodiment of Example 10.
FIG. 25 is a view showing an aperture of a bushing base raw plate of Example 11.
FIG. 26 is a sectional view showing a hollow tube of Example 10.
FIG. 27 is a sectional view showing a bushing base plate of Example 10.
FIG. 28 is a sectional view showing a bushing base raw plate of Example 12.
FIG. 29 is a sectional view showing a hollow tube of Example 12.
FIG. 30 is a sectional view showing a bushing base plate of Example 12.
FIG. 31 is a microphotograph showing a sectional organization of a bushing base plate obtained in Example 8.
DETAILED DESCRIPTION OF THE INVENTION
Since the hollow tube constituting the flow-out aperture is inserted into the aperture perforated through the flat plate at a certain interference and fixed to the bushing base raw plate and bonded by means of thermal diffusion in the first invention, the metal materials of the both elements diffuse to each other in the the outer periphery of the aperture of the bushing base plate side and of the hollow tube under a condition of being fixed and pressed at a certain interference and the two elements are bonded so that its strength is the same as that of the mother material. "A certain interference" employed herein means a difference between the outer diameter of the hollow tube and the inner diameter of the aperture when the former is larger than latter, which produces a pressing force after the insertion and fixation.
When the portions to be bonded extend to the whole area and the firm bonding is required, the hollow tube is inserted into and fixed to the aperture of the bushing base raw plate side without the presence of air, another gas or impurities between the aperture and the outer surface of the hollow tube so that the thermal diffusion may be conducted on the whole surface to be bonded. Since, in this way, the same bonding strength as the strength of the mother material may be obtained neither cracks nor defects can be produced even if the bushing base plate is deformed after it is employed for a long period of time. Since, further, the spinning of the glass fibers is conducted at a temperature of 1100 to 1400° C., the thermal diffusion further proceeds during the operation so that no lowering of the bonding strength is expected.
When a flow-out aperture having a thin wall is required for manufacturing thin glass fibers or the like, the strength of the pipe itself is low, and if the bushing base raw plate and the base end of the pipe are perpendicularly crossed, the weight of the glass and the spinning strength may damage the crossed portion. For reinforcing the crossed portion, a hollow tubular swelling is formed on the bushing base raw plate and a hollow tube or a thin wall pipe is inserted into an aperture perforated through the central portion of the swelling so that the bonding portion of the bushing base raw plate and the pipe constituting the flow-out aperture is guarded by the swelling so as to provide no chance of destruction of this bonding portion.
In the present invention, the simple bonding may satisfy the object thereof, or the bonding portion may be further strengthened effectively in view of its shape by molding the shape of the flow-in aperture into which glass flows in by means of plastic processing or by changing the length and the shape of the swelling and the hollow tube. Another hollow tube made of different material may be employed or the material of the flow-out aperture may be that composed of Pt or an Pt alloy and Au alloyed therewith. No lowering of strength is expected.
Also according to the process of the second invention, the same function as that of the first invention may be realized. However, in the second invention, the hollow tube can also be inserted into the aperture after the tube is enlarged from the inside.
As mentioned in the bushing base plate of the third invention, the bushing base raw plate and the hollow tube are tightly fixed to each other by the plastic deformation treatment at the time of inserting the hollow tube into the aperture of which a aperture size of the glass flow-in side is larger perforated through the bushing base raw plate or thereafter, and are bonded by means of the thermal diffusion. The careful inserting operation and the careful plastic deformation processing for eliminating the contamination of gas and impurities enable to maintain the inner aperture surface of the bushing base plate and the outer hollow tube surface clean and to keep them tightly. Since they are subjected to the thermal treatment under the condition that they are fixed under a certain inner pressure, the both metal materials are bonded to each other by means of the mutual diffusion to make the strength the same as that of the original metal material. The plastic deformation processing after the thermal diffusion and the next thermal diffusion enable to obtain not only a firmly bonded product but also a smooth bonded surface at the bonding boundary recognized on the surface. The shape of the hollow tube may be any one of a straight tube, tapered tube, a rounded tube, and may be one having a tapered or rounded portion at an upper end thereof or one having a stepped portion. In case of the tapered or rounded tube, in order to introduce impurities, a gas and the like between the said tapered portion or rounded portion and the hollow tube to maintain a constant inner pressure both on the clean metal surfaces, it is necessary to make the outer size of a part of the tapered or rounded portion larger than the aperture size of glass flow-out side of the bushing base raw plate. It is necessary to suitably adjust the size of the aperture perforated through the bushing base raw plate and the tapered angle and the rounded portion so s to tightly adhere from the upper portion of the tapered or rounded portion to the lower portion thereof to the whole surface of the aperture of the bushing base raw plate or the aperture wall of the glass flow-out size. When the number of tapers is one, the tapered angles of the aperture of the bushing base raw plate and of the tapered portion formed on the hollow tube is preferably between 0.01 and 120°, and when the the said number is two or more, at lest one of the tapered angles is preferably between 0.01 and 120°. The reasons thereof are that no effect can be produced when the angle is below this value, and the inner diameter of the hollow tube is made to be too small in relation to the diameter of the glass glow-out side of the bushing base plate ordinarily employed considering the relation between the thickness of the bushing base plate and the diameter of the glass flow-out side so as to make the employment of the hollow tube meaningless when the angle exceeds the above value so that no effects may be obtained by the presence of the tapered portion.
When the periphery of the hollow tube at the glass flow-out side of the bushing base raw plate is coated with the base plate raw plate material, the bonding between the bushing base raw plate and the hollow tube is made to be stronger. Since the thickness of the bushing base raw plate is made to be as thin as possible in the view point of economy so long as it may be endured, the length may be insufficient required for the bonding but the bonding strength per a flow-out aperture increases with the increase of the bonding area. The most important is that when the bushing base plate is deformed and curved by the pressure of glass after a long period of time of operation, the deformation of the bushing base plate by means of the curvature accompanies the deformation of the aperture due to the bending of the lower portion of the bushing base plate. When in this case the hollow tube is coated for reinforcement, characteristically no deformation is produced at the lower portion bonded to the hollow tube by means of the coating. The sectional shape of the hollow tube employed may be appropriately selected depending on a sectional shape of a glass fiber desired. When the glass fiber having the circular section is desired the hollow tube having the circular outer and inner shapes is employed. When the glass fiber having the irregular section is desired, the hollow tube having the irregular outer and inner shapes is employed. The irregular shape employed herein is any shape such as a triangle, a square, an ellipse, an oval, a Y-shape and the like other than a circle.
In accordance with the process of preparing the bushing base plate of the present invention, the portions to be bonded can be orderly bonded over a whole area. For performing the orderly bonding, the insertion and the fixation are required to be carried out without the introduction of air, another gas and impurities between the aperture of the bushing base raw plate and the outer surface of the hollow tube to be bonded. Since, according to the process of the invention, the wall of the tapered aperture of the bushing base raw plate is tightly adhered to the periphery of the hollow tube while the aperture is rubbed with the top or middle portion of the hollow tube when the hollow tube is inserted into the tapered aperture perforated through the bushing base plate, such an impurity as air, a gas or the like present on the aperture wall is expelled by the top or middle portion of the hollow tube so that the bonding can be carried out under the condition free from these impurities. When the thermal diffusion is performed under the said condition free from the impurities, the thermal diffusion can be completely conducted over the whole are of the bonded portions. Since the same bonding strength as the material strength of the mother material is obtained, neither cracks nor defects are produced even if the bushing base plate is deformed after a long period of time of operation.
When the material of at least one of the both members to be bonded (bushing base raw plate and hollow tube) is platinum of which grains are stabilized by an oxide or a platinum alloy of which grains are stabilized by an oxide, this kind of material loses the oxide mainly participating in the reinforcing mechanism which floats to the surface and no stabilized grains exist at the welded portion in case that the welding is employed for the bonding so that the material loses its characteristic as the platinum of which grains are stabilized by an oxide or the platinum alloy of which grains are stabilized by an oxide. Since the considerable lowering of the strength occurs at the bonded portion due to the above reason, a problem arises that the strength at the portion becomes very weak. Since, however, no welding is conducted in the process of the present invention, no lowering of the strength occurs so that the strength at the bonded portion can be the substantially same as that of the raw material.
For reinforcing the hollow tube by coating the periphery thereof at the glass flow-out side of the bushing base plate with the base raw plate material, a swelling may be formed surrounding the aperture at the glass flow-out side of the bushing base raw pate when the glass flow-out aperture is produced through the bushing base plate, and when the periphery of the aperture at the glass flow-in side is molded or the flow-out aperture is adjusted to a desired shape and dimensions after the bonding of the hollow tube to the bushing base raw plate, the approach of the bushing base raw plate material to the periphery of the hollow tube may be utilized for forming the above coating of the base raw plate material at the time of forming the taper by employing a mold of which an inlet shape has a taper or a step and which receives the flow-out aperture.
The reason why the temperature of thermal treatment is restricted to the range between 500° C. and a temperature 20° C. lower than the melting point of the material is that the diffusion does not occur below 500° C. and the control of the temperature distribution can be performed only in a limited range and the temperature may partially exceed the melting point of the material resulting in the melting of the material if the temperature exceeds the point 20° C. lower than the melting point of the material.
The material employed for the bushing base raw plate and for the hollow tube is selected in consideration of the material of melted glass, spinning conditions and an intensity life, and if Au is added to the material of the hollow tube, the material is difficult to be wetted with glass and an end breakage of the glass during the spinning seldom occurs so that the stable spinning may be obtained.
EXAMPLES
Examples of a bushing base plate and its preparation according to the present invention will be described referring to the drawings. However, these Examples do not restrict the present invention. At first, Examples of a bushing base plate and its preparation according to the first and the second invention swill be describes as Examples 1 to 5, and then other Examples according to the third and fourth inventions will be describes as Examples 6 to 12.
Example 1
At first, a PT--Rh (10%) alloy employed as bushing base raw plate material was rolled by means of a rolling machine to a thickness of 1.5 mm and was cut to a piece having a width of 100 mm and a length of 500 mm. Through this raw plate 11, 800 holes were zigzag perforated with a pitch of 3.5 mm by means of press processing to make apertures 12 as shown in FIG. 4. The size of the aperture through the bushing base plate was 1.9 mm in diameter.
A hollow tube 13 as shown in FIG. 5 was draw-processed, cut and molded to have an outer diameter of 2.0 mm, an inner diameter of 1.5 mm, a thickness of 0.25 mm ad a height of 6.5 mm. After this hollow tube 13 was set on the aperture 12, a die of which a dimension was larger than the aperture 12 perforated through the bushing base raw plate 11 by 0.2 mm was set under the plate and the hollow tube was inserted into the aperture employing a punch having the same dimension as the outer diameter of the hollow tube 13 as an upper die at an interference of 0.05 mm, the thermal diffusion at 1400° C. was conducted for five hours in an electric furnace. It was confirmed that the fixed portion became the same material because the grains at the bushing base plate's aperture 12 side and at the outer periphery of the hollow tube 13 diffused to each other so that the crystal growth spanned the boundary of the bonding and that the bonding was completed over the whole area. A bushing was prepared by bonding the bushing base plate thus obtained to an upper box-like vessel constituting a terminal and a fusion furnace with a filter by means of arc welding.
Example 2
During the molding of the above bushing base plate, a swelling 14 having the shape shown in FIG. 7 was formed on the bushing base raw plate by means of press processing and an aperture 12 was perforated through the cantral portion thereof. The diameter of the aperture was 1.9 mm and the length was 3 mm. A hollow tube 13 having an outer diameter of 2.0 mm, an inner diameter of 1.5 mm and a thickness of 0.25 mm was inserted into the aperture 12 at an interference of 0.05 mm, and according to the same conditions of Example 1, a bushing plate shown in FIG. 8 was obtained.
Example 3
In the processes of Examples 1 and 2, the thermal diffusion at 1400° C. was carried out for five hours in an electric furnace and then the plate as molded by means of pressing and by employing a punch having a taper and a die to form a taper of 30° at the glass flow-in side and a two step taper at the flow-out side to prepare a similar bushing plate to those of the above Examples. While, in addition, base plates shown in FIGS. 10 and 11 were prepared by means of molding, they were excellent in the shape and the bonding conditions.
Example 4
The same processing as that of Example 3 was performed employing a Pt(95%)--Au(5%) alloy as material of the hollow tube or the flow-out aperture. The reason why 5% of Au was added was to achieve the improvement of anti-wettability at the time of spinning. The splendid effects for bonding were obtained partially because the diffusion speed of Au was high.
Example 5
During the molding of the bushing base plate in Example 1, a swelling 14 having the shape shown in FIG. 7 was formed on the bushing base raw plate by means of press processing and an aperture 12 was perforated through the cantral portion thereof. The diameter of the aperture was 2.5 mm and the length was 3 mm. A hollow tube 13 having an outer diameter of 2.45 mm, an inner diameter of 1.95 mm and a thickness of 0.25 mm was inserted into the aperture 12, and the inner diameter of the hollow tube was increased to 2.1 mm by enlarging the original inner diameter of the hollow tube employing a punch hang a top planar bullet like end of which a diameter was 2.1 mm in a die which is not shown. The hollow tube was fixed to the aperture 12 at the center of the swelling 14 at a certain interference and the thermal treatment at 1400° C. was conducted in an electric furnace for three hours followed by the same preparation processes to obtain a bushing base plate having a section shown in FIG. 8.
Upon completion of the thermal treatment, a taper of 30° may be formed at the glass flow-in side by means of plastic processing as shown in FIG. 9 and the thermal treatment may be repeated.
Glass fibers manufactured by employing the respective bushings of Examples 1 to 5 exhibited a longer life than glass fibers manufactured with a conventional bushing. Moreover in Example 4, end breakage during spinning was scarce because the top chip portion was difficult to be wetted.
Example 6
At first, a PT--Rh (10%) alloy employed as bushing base raw plate material was rolled by means of a rolling machine to a thickness of 1.5 mm and was cut to a piece having a width of 50 mm and a length of 400 mm. Through this raw plate 21, 400 holes were perforated having a circular section by means of press processing as shown in FIG. 12 The dimensions were as follows. Diameter of glass flow-in side of the bushing base plate (d 1 ) was 2.5 mm, a diameter of a glass flow-out end (d 2 ) was 2.1 mm and a tapered angle θ 1 was 15.2°.
A Pt--Au (5%) alloy was processed by drawing and cutting to obtain a pipe-like hollow tube 23 which had, as shown in FIG. 13, inner and outer circular shapes of which an outer diameter, an inner diameter and a length were 2.6 mm, 2.0 mm and 6 mm, respectively, and had one tapered end having an outer diameter of 1.9 mm formed by means of pressing.
The hollow tube 23 shown in FIG. 14 was inserted into an aperture perforated through the above bushing base raw plate 1 from its larger diameter side, and fixed thereto as shown in FIG. 15. Thereafter, a thermal treatment at 1400° C. was conducted for three hours to bond the bushing base raw plate 21 and the hollow tube 23 by means of thermal diffusion, and the one end of the hollow tube 23 was made back to a straight pipe by plastic deformation to obtain a bushing base plate 24 as shown in FIG. 16.
The section of the bushing base plate 24 thus obtained was observed with a microscope to find out that the materials of the both of the bushing base raw plate and the hollow tube 23 were diffused through the thermal diffusion at the boundary to constitute an integrated material in which the crystals thereof were intricate and the sufficient metal bonding was obtained.
Example 7
A Pt--Rh(10%)--Pd(5%) alloy employed as bushing base raw plate material was rolled by means of a rolling machine to a thickness of 1.5 mm and was cut to a piece having a width of 70 mm and a length of 600 mm. Through this raw plate 21, 800 holes were perforated having a circular section by means of press processing as shown in FIG. 12. The dimensions were as follows, d 1 =2.2 mm and d 2 =1.6 mm, and a tapered angle θ 1 was 22.6°.
A Pt--Rh(10%)--Au(5%) alloy was processed to obtain a pipe-like hollow tube 23 which had, as shown in FIG. 17, inner and outer circular shapes in which d 3 =2.4 mm, d 4 =1.5 mm, a tapered angle θ 2 is 16°, t 1 =0.2 mm and l 1 =6 mm.
The hollow tube 31 was inserted into an aperture perforated through the above bushing base raw plate 21 and fixed thereto as shown in FIG. 18. Thereafter, a thermal treatment at 1200° C. was conducted for six hours to bond the bushing base raw plate 21 and the hollow tube 23 by means of thermal diffusion to obtain a bushing base plate 24.
The section of the bushing base plate 24 thus obtained was observed with a microscope to find out that the materials of the both of the bushing base raw plate 21 and the hollow tube 23 were diffused through the thermal diffusion at the boundary to constitute an integrated material in which the crystals thereof were intricate and the sufficient metal bonding was obtained.
Example 8
A platinum plate of which grains are stabilized by an oxide prepared by internally oxidizing Pt, bushing base raw plate material, by means of the addition of 0.3% of Zr was rolled by means of a rolling machine to a thickness of 1.5 mm and was cut to a piece having a width of 70 mm and a length of 600 mm. On this raw plate 31, a hollow tube like swelling having a circular section was formed by means of press processing as shown in FIG. 19. The dimensions were as follows. d 6 =2.4 mm and d 7 =1.8 mm, t 2 =0.5 mm, l 2 =3.0 mm and θ 2 =11.4°.
A Pt--Zr(0.3%) alloy was processed by drawing and cutting to obtain a hollow tube 33 of which a shape was circular as shown in FIG. 20 having an outer diameter of 2.6 mm, an inner diameter of 2.0 mm and a length of 7 mm, and having a tapered end of which an outer dimension was 1.7 mm.
The hollow tube was inserted into an aperture perforated through the above bushing base raw plate 31 and fixed thereto as shown in FIG. 20. Thereafter, a thermal treatment at 1400° C. was conducted for 12 hours to bond the bushing base raw plate 31 and the hollow tube 33 by means of thermal diffusion to obtain a bushing base plate 34.
The section of the bushing base plate 34' thus obtained observed with a microscope was as shown in FIG. 21 in which the organization of the hollow tube and the bushing base raw plate was identical and no boundary was observed so that the both were bonded more firmly.
Example 9
After the periphery of the aperture at the glass flow-in side was processed by pressing to the shape having a tapered angle of 30° employing the bushing base plate shown in FIG. 16 obtained in Example 5, the plastic deformation was caused for enlarging the inner diameter by 0.2 mm to prepare a bushing base plate 44 as shown in FIG. 22.
The section of the bushing base plate 44 thus obtained was observed with a microscope to find out that no boundary between the hollow tube 43 and the bushing base raw plate 41 was observed and the sufficient metal bonding was obtained.
Example 10
A taper-like plastic deformation was caused by press processing the periphery of the aperture at the glass flow-in side providing as a lower mold at the time of pressing a mold having a taper at the periphery of the inlet for inserting the hollow tube therein as shown in FIG. 23 while employing the bushing base plate shown in FIG. 16 obtained in Example 6. Thereafter, the thermal diffusion treatment at 1400° C. was again conducted for one hour to obtain a bushing base plate 54 plastically deformed as shown in FIG. 24.
The bushing base plate 54 thus obtained was covered and reinforced with the bush base raw plate material at the periphery of the hollow tube of the glass flow-out side of the bushing base raw plate 51.
Example 11
The sectional shapes of the apertures perforated through the bushing base raw plate of Example 5 were made to be elliptic as shown in FIGS. 25 (a) and (b) of which dimensions were as follows. Glass flow-in side: d 8 =1.5 mm, d 10 =3.5 mm and r 1 =0.75 mm. Glass flow-out side: d 9 =1.3 mm d 11 =3.3 mm and r 2 =0.65 mm. The shape of the hollow tube was made to be one shown in FIGS. 26 (a), (b) and (c) of which dimensions were as follows. Glass flow-in side; d 12 =1.6 mm, d 13 =1.1 mm, r 2 =0.8 mm, d 14 =3.6 mm, d 15 =3.1 mm and r 4 =0.55 mm, Glass flow-out side: d 16 =1.2 mm, d 18 =3.2 mm, d 17 =0.77 mm, d 19 =2.7 mm, r 5 =0.6 mm and r 6 =0.35 mm. The conditions were the same as those of Example 5 except that the length of the hollow tube was 7 mmm and the tube had a taper on the whole length. After the thermal diffusion, the periphery of the aperture of te glass flow-in side was press processed to have a taper and the bonded member was thermally treated at 1200° C. for one hour followed by the deformation of the flow-out aperture to a straight one to obtain a bushing base plate 64 as shown in FIG. 27.
The section of the bushing base plate 64 thus obtained was observed with a microscope to find out that the materials of the both of the bushing base raw plate and the hollow tube 63 were diffused through the thermal diffusion at the boundary to constitute an integrated material in which the crystals thereof were intricate and the sufficient metal bonding was obtained.
Example 12
The sectional shape of an aperture perforated through a platinum-rhodium ally plate of which grains are stabilized by an oxide employed as bushing base raw plate material was that having two-step tapers as shown in FIG. 28 and the following dimensions, θ 1 =90°, θ 2 =10°. The sectional shape of the hollow tube was that as shown in FIG. 29 to have the following dimensions. θ 3 =85°, θ 4 =8°, d 3 =3.6 mm and d 4 =2.2 mm. After the hollow tube was inserted into the aperture of the raw plate 71 and fixed thereto as shown in FIG. 30, the thermal treatment was conducted at 1500° C. for one hour for bonding the bushing base raw plate 71 and the hollow tube 73 by means of thermal diffusion to prepare a bushing base plate 74.
The section of the bushing base plate 74 thus obtained was observed with a microscope to find out that the materials of the both of the bushing base raw plate and the hollow tube 73 were diffused through the thermal diffusion at the boundary to constitute an integrated material in which the crystals thereof were intricate and the sufficient metal bonding was obtained.
A bushing was prepared by bonding the respective bushing base plates obtained in Examples 1 to 12 to an upper box-like vessel constituting a terminal and a fusion furnace with a filter by means of arc welding. While glass fibers were continuously manufactured employing the bushing, no problems were observed after a lapse of half year in the bushings employing the bushing base plate of Examples 1 to 12. | A bushing base plate comprised of a bushing base raw plate containing a circular or irregular aperture having inner surfaces and inner diameters; and a hollow tube having outer surfaces and out diameters which is inserted into the aperture and bonded thereto by thermal diffusion. Prior to insertion of the tube in the aperture, the outer diameters are greater than the inner diameters, thereby producing a pressing force between the outer surfaces of the tube and the inner surfaces of the aperture. | 2 |
GOVERNMENT INTEREST
The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without payment to me of any royalty thereon.
BACKGROUND OF THE INVENTION
1. Field of the Invention
On one aspect this invention relates to devices for measuring distances. In another aspect, this invention relates to a device adapted to be moved by a person on foot to measure distances over land.
2. Prior Art
Distance measuring devices comprising a wheel with a known circumference mounted on a handle are known in the art. Such systems have a counter mounted to the axle of the wheel to measure the number of revolutions and convert the revolutions to feet.
These devices are useful over normal flat surfaces or terrain such as that found in cities. However, they are not well adapted for use in less developed areas, they require visual inspection of the counter, and the counting mechanism tends to be unreliable and noisy.
There is a need for a quiet distance measuring device which can be used by the foot soldier to measure distances, which does not make noise to indicate the soldier's presence and which will provide a tactile stimulus in use so a soldier knows the distance traveled without the need to read a gage or dial. Also the device should operate in undeveloped terrain without having the measuring wheel slide or the counter mechanism slip.
BRIEF SUMMARY OF THE INVENTION
The present invention discloses a distance measuring device with a frame having a handle and adapted to hold first and second wheels in a spaced relationship. Each wheel is mounted in the frame so as to freely rotate. An endless flexible belt is mounted on the first and second wheels, the flexible belt being constructed so it will rotate when one of the wheels is rotated. A hand contacting projection is attached to the flexible belt at a position where the projection will contact the hand of a user of the device who is holding the handle once each time the belt revolves.
BRIEF DESCRIPTION OF THE DRAWING
In the accompanying drawing; the FIGURE is an isometric projection of one embodiment of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The accompanying drawing discloses one preferred embodiment of an invention formed in accordance with this invention. A distance measuring device of this invention is designated generally 10. The basic structure of the distance measuring device 10 comprises a frame 12 which is adapted to hold a first relatively smaller wheel 14 and a second relatively larger ground engaging wheel 16.
The first, smaller wheel 14, is mounted within a first yoke 18 on a first axle 20. The first, smaller wheel 14 has flanges 22 located on each end of a toothed drum 24 to form a pulley type structure. The first smaller wheel has a handle 26 located nearby for reasons which will be discussed later. As shown, the handle 26 is a Y-shaped structure with the legs being a continuation of the first yoke 18 to form a structure which encompasses the first smaller wheel 14 and has a shaped handgrip 28 adapted to be held by the person who is operating the distance measuring device 10 located so the user's hand will be kept in close proximity to the first smaller wheel 14.
The frame member 12 has a shaft 30 extending from the first yoke 18, the end of the shaft distal the first yoke terminating in a second yoke 32. The second yoke 32 serves as the mounting for the second, larger, ground engaging wheel 16. The second ground engaging wheel 16 is mounted on a second axle 34 for free rotation. The second ground engaging wheel 34 has a pair of spaced flanges 36 which are located on either side of a toothed drum 38 to also form a pulley like structure. The flanges of the first smaller wheel 14 and the second ground engaging wheel 16 cooperate to define a channel with the toothed drum serving as the bottom of the channel, adapted to receive a power transmitting belt.
The power transmitting belt shown is a flexible belt 40 having a plurality of apertures 42 formed into an endless loop which lies in the channel formed by the flanges of the first and second wheels. The spacing of the teeth on the toothed drum 24 and the second toothed drum 38 correspond with the apertures 42 in the flexible belt 40 so rotation of the ground engaging wheel causes movement of the belt. The flexible belt 40 has a soft hand contacting projection 44 which is shown as a loop but could take other forms. The projection 44 is adapted to gently contact the hand of the user on the handle 26 as the flexible belt 40 rotates to provide a tactile stimulation. By properly dimensioning the measuring device, it is possible to make each revolution of the belt indicate a standard unit, i.e., 10 feet.
When used, the measuring device of this invention is gripped by the handle 26, the ground engaging wheel 16 positioned and the device moved forward. Each time the loop contacts the user's hand they can add another increment to the total distance traversed. Because there are no counters the device is essentially silent. Also because the device provides a tactile stimulus on a continuous basis the user has a running indication of the distance traversed. This is true even though it is dark since the user need not read a counter. Thus a military person can move the measuring device to measure distances or use it to measure the distance to a particular location. Because of its construction the device is simple to operate and trouble free.
As shown the handle has a rigid shaft 30 but the handle can be made so it collapses to make storage and transportation easier.
The choice of part sizes to achieve the desired distance represented by one belt revolution, is within the skill of the art. One example might be for a 10 foot loop. If the first smaller wheel has a drum diameter of about 2.6 inches and the larger ground engaging wheel has a drum diameter of about 11 inches and the outer diameter of the ground engaging wheel is about 13.3 inches the distance between the axles will be about 38.4 inches. This makes the over all length of the device about 48 to 50 inches including the handle. The resulting measuring device is appropriately sized for use by the average person.
I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described for obvious modifications will occur to a person skilled in the art, without departing from the spirit and scope of the appended claims. | A distance measuring device includes first and second wheels having an endless belt looped about the wheels so the belt rotates as a ground engaging wheel. A hand contacting member is attached to the belt so as to provide positive sensory input to the device user when measuring distances. | 6 |
This application claims priority of U.S. Provisional Patent Application No. 60/125,850, filed on Mar. 24, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to an improved nozzle for use in wear-resistant rotary atomizers, to atomizer wheels containing said improved nozzles and to a method for employing said nozzles.
2. Discussion of the Prior Art
Wear-resistant rotary atomizers are described in Niro patents U.S. Pat. No. 3,454,226, U.S. Pat. No. 4,121,770 and U.S. Pat. No. 4,684,065. Those patents describe atomizer wheels for atomizing slurries of a highly abrasive material, comprising a wheel hub and a mainly cylindrical external wall defining an annular chamber of a substantially bowl-like cross-sectional shape coaxially surrounding said hub, a number of substantially horizontal and radial ejection apertures distributed over the circumference of said external wall. During operation the supplied slurry is ejected outwards through said ejection apertures in atomized form into a surrounding drying chamber in which the fine particles formed by the atomization are dried so that their content of solids drops down to the bottom of the drying chamber as a fine powder.
U.S. Pat. No. 3,454,226 describes nozzles of a wear-resistant sintered material arranged in each of said apertures fitting loosely with respect to said external wall, the nozzles projecting into said annular chamber. The use of wear-resistant sintered material for the nozzles was stated to be necessary because of the very hard wear which takes place on account of the very high velocities of discharge from the atomizer wheel caused by the centrifugal force when atomizing suspensions which contain solid particles of a hard material.
In U.S. Pat. No. 4,684,065 the nozzle of U.S. Pat. No. 3,454,226 is replaced by a nozzle assembly which comprises a lining of wear-resistant sintered material arranged in the apertures by means of replaceable steel bushings fitting loosely with respect to said external wall. The nozzle assembly is held in place by flexible sealing rings which also prevent liquid penetrating into the space between the aperture wall and the nozzle assembly. A flat recess is formed in the internal side of the bushing facing the lining arranged therein. Said flat recess extends in the axial direction of the bushing on either side. The claimed advantage of this design is that upon inevitable flexing of the atomizer wall under rotation, the bushing can deform without fracturing the brittle ceramic liner arranged therein.
The nozzles described in the above-mentioned patents and the commercially available nozzles have flow channels of essentially cylindrical shape, although in FIG. 4 of U.S. Pat. No. 3,454,226 also a nozzle having a square cross-section is depicted. The specific designs described in the prior art provide atomizer wheels and nozzles which are highly wear-resistant and have a long lifetime. The present invention provides atomizer wheels and nozzles having the same wear resistance as the ones described in the Niro patents or even better, but at the same time, the nozzles have been improved to provide microspherical particles with a more narrow particle size distribution.
SUMMARY OF THE INVENTION
In one embodiment, the present invention is a nozzle for a rotary atomizer comprising a flow channel in the form of a vertical slot.
In a second embodiment, the present invention is an atomizer wheel for atomizing slurries of a highly abrasive material, comprising a wheel hub and a mainly cylindrical external wall defining an annular chamber of a substantially bowl-like cross-sectional shape coaxially surrounding the hub. A number of substantially horizontal and radial ejection apertures are distributed over the circumference of the external wall. A nozzle comprised of a wear-resistant sintered material is arranged in each of said apertures and fitts loosely with respect to the external wall. The nozzle projects into the annular chamber and has a flow channel in the form of a vertical slot.
In a third embodiment, the present invention is a method of obtaining solid particles of relatively small particle size distribution. A slurry of solid material is atomized by ejecting the slurry through at least one ejection nozzle into a drying chamber in which particles of the solid material are formed by the atomization are dried and collected. The ejection nozzle comprises a flow channel in the form of a vertical slot.
Other embodiments of the invention lie in details concerning nozzle constriction, particularly with regard to the handling of abrasive solid material, and details concerning the method of obtaining the solid particles.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial horizontal sectional view of the nozzle according to the invention,
FIG. 2 is a partial vertical sectional view of the nozzle according to the invention,
FIG. 3 is a partial sectional view of an atomizer wheel with a nozzle according to an embodiment of the invention,
FIG. 4 is a partial sectional view of an atomizer wheel with a nozzle according to another embodiment of the invention, and
FIG. 5 is a three-dimensional illustration of the flow channel present in the nozzles according to the prior art.
FIG. 6 is a three-dimensional illustration of the flow channel present in the nozzles according to the invention,
FIG. 7 gives a graph of the percentage of product obtained having a diameter of less than 38 microns plotted against the percentage of product having a percentage larger than 150 microns.
DETAILED DESCRIPTION OF THE INVENTION
The nozzle of the present invention comprises a flow channel in the shape of a vertical slot. It was found that when these improved nozzles are used for spray-drying suspensions, microspherical particles with a narrower particle size distribution are obtained than when using nozzles with cylindrical flow channels. Since it is contemplated that the suspensions being spray dried may comprise abrasive particles, the flow channel within the nozzle may be lined with wearresistant sintered material.
Within the context of this specification, the term “wear-resistant sintered material” means a material where the hard grains are stably interconnected no matter whether such interconnection has been effected by fusing together the surfaces of the grains or by embedding the grains in some basic substance such as, by way of example, is being used in the manufacture of tungsten carbide bodies. The term “vertical slot” means a slot where the horizontal axis is shorter than the vertical axis.
To ensure flow stability, it is preferred that the flow channel of the nozzle has the form of a uniformly rounded slot. The term “uniformly rounded” means that the cross-section of the slot perpendicular to the flow direction has rounded corners. Large radii of curvature are preferred at the inlet of the flow channel to ensure flow stability. The flow channel may be tapered.
For the inlet radii of curvature it has been found that when the horizontal radius of curvature is larger than the vertical radius of curvature, the nozzle provides a combination of optimal liquid spreading along the wall of the flow channel, which results in homogeneous atomization, and optimal flow capacity, which results in low viscous drag and inlet turbulence. Herein the horizontal radius of curvature and the vertical radius of curvature are defined as follows. When using x to refer to the direction along the minor axis of the slot, y is down the flow channel and z is vertical, i.e. along the major axis of the slot. To generate the surface having the horizontal radius of curvature, a 90° arc must be taken in the xy (horizontal) plane with a radius rh, and it must be extruded in the z direction. To generate the surface of revolution with the vertical radius of curvature, the 90° arc is placed in the yz (vertical) plane with radius rv. However, because the ends of the slot are rounded, this arc is not extruded along x but rather, is rotated around the centerline of the rounded hemicircle at the ends of the slot.
The optimal dimensions for the slot height (the vertical axis) are determined by the desired particle size distribution improvement and the size limitations of the atomiser wheel. The optimal slot width (the horizontal axis) can be selected to give approximately the same cross-sectional area for the flow channel as typically found in the nozzles of the prior art as described in the Niro patents.
It was found that when the nozzle of the present invention is used, it is not necessary to employ a two-piece nozzle assembly with a metal bushing. A single-piece nozzle made entirely of wear-resistant sintered material can survive the rotational forces and wall flex, so long as flexible sealing rings are employed between the nozzle and the ejection aperture. Such sealing rings are described in U.S. Pat. No. 4,684,065. For further details reference is made to this patent.
Of course, the nozzle according to the invention may also be a two-piece nozzle assembly comprising a metal bushing lined with a lining of a wear-resistant sintered material having a flow channel in the form of a, preferably uniformly rounded, vertical slot. Suitable metals for the bushing include (stainless) steel, nickel alloys such as hastelloy, titanium, tantalum, zirconium etc. Said steel bushing may further be provided with a flat recess so as to avoid fracture of the wear-resistant sintered lining material upon deformation of the steel bushing due to the high rotational forces. In this embodiment flexible sealing rings can also be employed.
In a further embodiment of the invention, the nozzle is provided with an outwardly directed shoulder abutting against a correspondingly shaped, oppositely directed shoulder in the ejection aperture of the atomizer wheel. During atomization of the slurry, the nozzles may be exposed to wear which from time to time may even be very heavy. This wear, however, is restricted to certain well-defined areas. In the present embodiment, the nozzle can be rotated around the axis of the flow channel as it gradually becomes worn, in order to increase its lifetime.
The present invention is further directed to an atomizer wheel for atomizing slurries of a highly abrasive material, comprising a wheel hub and a mainly cylindrical external wall defining an annular chamber of a substantially bowl-like cross-sectional shape coaxially surrounding said hub, a number of substantially horizontal and radial ejection apertures distributed over the circumference of said external wall, with a nozzle comprised of a wear-resistant sintered material arranged in each of said apertures fitting loosely with respect to said external wall, said nozzle projecting into said annular chamber and having a flow channel in the form of a vertical slot. To ensure flow stability, it is preferred that the flow channel of the nozzle has the form of a uniformly rounded vertical slot.
The atomizer wheel may be provided with one-piece nozzles made entirely of wear-resistant sintered material or with two-piece nozzles comprising a metal bushing lined with a wear-resistant sintered lining. Further, the nozzles may be provided with an outwardly directed shoulder abutting against a correspondingly shaped, oppositely directed shoulder in the ejection aperture of the atomizer wheel.
The atomizer wheel illustrated in FIG. 3 comprises an annular chamber 2 having a substantially bowl-like cross-sectional shape provided with a central hub 1 , a substantially cylindrical external wall 3 , a surrounding drying chamber 3 a , and a cover 5 . In the cover 5 an aperture 6 is provided concentrically around the hub 1 through which the slurry to be atomized is supplied to the atomizer wheel.
Along the circumference of the external wall 3 of the atomizer wheel a number of ejection apertures are provided, through which during operation a supplied slurry is ejected outwards in atomized form into a surrounding drying chamber in which the fine particles formed by the atomization are dried so that their content of solids drops down to the bottom of the drying chamber as a fine powder. In order to prevent wear on the atomizer wheel itself nozzles 7 of a wear-resistant sintered material are inserted in the individual ejection apertures.
The slurry entering the nozzle of the invention will contain particles of various composition and size. The minute droplets comprising the spray from the nozzle (liquid and solids in a gas dispersion) include the liquid of the suspension and solids comprising mixtures of the various component particles. When the droplets dry, olid particles comprising such mixtures may be recovered.
The nozzle of the invention as previously described is shown in FIG. 1 and FIG. 2 which are horizontal and vertical sectional views, respectively. These views of the nozzle illustrate the nozzle inlet 1 a comprising a uniformly rounded slot where the horizontal radius of curvature of the slot is larger than the vertical radius of curvature, as those terms have been previously defined. Also shown are outwardly directed shoulder 1 b and a groove 1 c around the outside of the nozzle for placement of the sealing ring.
FIG. 1 and FIG. 2 serve to graphically illustrate the definitions of “horizontal radius of curvature” and “vertical radius of curvature”, respectively, as given above.
The atomizer wheel illustrated in FIG. 4 comprises an annular chamber 2 having a substantially bowl-like cross-sectional shape provided with a central hub 1 , a substantially cylindrical external wall 3 , a surrounding drying chamber 3 a , a bottom portion 4 , and a cover 5 . In the cover 5 an aperture 6 is provided concentrically around the hub 1 through which the slurry to be atomized is supplied to the atomizer wheel.
Along the circumference of the external wall 3 of the atomizer wheel a number of ejection apertures are provided, through which during operation a supplied slurry is ejected outwards in atomized form into a surrounding drying chamber in which the fine particles formed by the atomization are dried so that their content of solids drops down to the bottom of the drying chamber as a fine powder. In order to prevent wear on the atomizer wheel itself, nozzles 7 comprising a bushing 8 with wear-resistant linings 9 are inserted in the individual ejection apertures. The bushing 8 is made from steel and provided with an outwardly directed shoulder 10 abutting against a correspondingly shaped, oppositely directed shoulder 11 in the ejection aperture. As mentioned before, the bushing 8 is fitting loosely in the aperture and, in order to prevent particles from penetrating into the clearance thus provided, it is sealed against the external wall 3 by means of a sealing ring 12 arranged near the inner surface of the wall 3 .
To allow elastic deformation of the bushing without transferring excessive stresses to the ceramic lining 9 , the bushing 8 is provided with a flat recess 13 in its inner surface facing the lining. In the embodiment shown, the recess 13 extends from below the recess of the sealing ring 12 and close to the internal end of the bushing 8 , i.e. substantially throughout that portion of the bushing which in the worst case is exposed to stresses which if transferred directly to the ceramic lining could damage it.
In FIG. 5 a three-dimensional illustration of the flow channel present in the nozzles according to the prior art is given. Such conventional nozzles have an essentially cylindrical shape.
In FIG. 6 a three-dimensional illustration of the flow channel present in the nozzles according to the invention is given. The nozzles according to the invention have flow channels in the form of a uniformly rounded vertical slot. In FIG. 5 a graph is provided which shows that a smaller particle size distribution is obtained when spray-drying a slurry using the atomizer wheel and nozzle according to the invention. The graph shows that an about 2% reduction in absolute amount of product having a particle size of less than 38 microns is obtained at a constant percentage of product greater than 150 microns. This amounts to a 10 to 20% narrowing of the particle size distribution.
In FIG. 7 a graph is provided which shows that a smaller particle size distribution is obtained when spray-drying a slurry using the atomizer wheel and nozzle according to the invention. The graph shows that an about 2% reduction in absolute amount of product having a particle size of less than 38 microns is obtained at a constant percentage of product greater than 150 microns. This amounts to a 10 to 20% narrowing of the particle size distribution. | The present invention pertains to an improved nozzle, particularly for use in wear-resistant rotary atomizers, to atomizer wheels containing such improved nozzles and to a method for obtaining microspherical particles with a narrower particle size distribution when using such nozzles. The atomizer wheels and nozzles have at least the same wear resistance as those described in the prior art, but have been improved to provide microspherical particles with a very narrow particle size distribution. The nozzle of the present invention comprises a flow channel in the shape of a vertical slot that may be lined with wear-resistant sintered material. The vertical slot may be uniformly rounded. It was found that when these improved nozzles are used for spray-drying suspensions, microspherical particles with a narrower particle size distribution are obtained than when using nozzles with cylindrical flow channels. | 1 |
PRIORITY
[0001] This application claims the priority of Korean Patent Application No. 2002-56314, filed on Sep. 17, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a hybrid automatic repeat request (ARQ) system, and more particularly, to an adaptive hybrid ARQ method and apparatus that minimizes transmission delay by measuring an error degree of a frame in which error correction fails at a receiving terminal and retransmitting a parity bit in accordance with the error degree at a transmitting terminal, and a method of transmitting and receiving data in an adaptive hybrid ARQ system.
[0004] 2. Description of the Related Art
[0005] A hybrid ARQ system combines a basic ARQ technique, which requests retransmission from a transmitting terminal by detecting an error from a received signal, with a forward error correction (FEC) channel coding technique, which overcomes deterioration of the channel. The hybrid ARQ system is designed to increase the overall throughput of a wireless communications system in time-varying channels. The hybrid ARQ system uses three hybrid ARQ methods: type I, type II, and type-III. The hybrid type II ARQ method has been proposed to solve problems of the hybrid type I ARQ method. In this method, ARQ is adaptively used for a channel having a dynamic bit-error-rate depending on the state of the channel. Two codes are used in the hybrid type-II ARQ method. One code is used to generate an n-bit code word D by using an error detection code C 0 of (n, k) in a message bit k. The other code is used to generate a 2 k-bit parity block P(D) by using an error detection and correction code C 1 of (2 k, k) in a parity bit k. A new code word F=(D,P(D)) is generated using the code word D and the parity block P(D) that are respectively generated using the two codes C 0 and C 1 . When a block D of a new code word F is transmitted and an error is detected at a receiver side using the error detection code C 0 , the received block D is stored in a buffer, and retransmission is requested from a transmitter side. Upon this request, if the transmitter side retransmits only the parity block P(D), when a syndrome is calculated and an error is not detected at the receiver side, the code word D can be recovered using the parity block P(D). However, if the error is detected at the receiver side, the error is corrected by means of the error detection and correction code C 1 using the block D stored in the buffer and the parity block P(D). If error correction fails in the two steps, the block D stored in the buffer is discarded and the parity block P(D) instead is stored in the buffer, and then, retransmission is requested from the transmitter side. The transmitter side that has been requested of retransmission retransmits the block D, instead of the parity block P(D), so as to repeat the error detection and correction procedure. Even when the block D is received free of errors or an error is detected, the above procedure is repeated until a code word that can correct the error successfully is received.
[0006] An example of the hybrid type-II ARQ method is illustrated in FIG. 1. Referring to FIG. 1, a transmitter 110 transmits a data frame comprising a parity bit 121 and a data bit 122 that are generated using a code having a high coding rate during initial transmission. A receiver 130 receives the data frame and performs channel decoding of the received data frame. If channel decoding fails, the receiver 130 transmits a negative acknowledgement (NACK) message 123 to the transmitter 110 . When receiving the NACK message 123 , the transmitter 110 transmits a parity frame comprising a parity bit 124 that is generated using a code having a lower coding rate than an initial coding rate.
[0007] Next, the receiver 130 corrects an error that occurs in a previous message using the transmitted parity bit 124 . If this error correction is successful, the receiver 130 transmits an ACK message 127 to the transmitter 110 . If the error correction is not successful, the receiver 130 transmits a NACK message 125 to the transmitter 110 . When receiving the NACK message 125 , the transmitter 110 transmits a parity frame comprised of a parity bit 126 that is generated using a code having a lower coding rate than a previous coding rate. The receiver 130 corrects an error that occurs in a previous message using the transmitted parity bit 126 . If this error correction is successful, the receiver 130 transmits the ACK message 127 to the transmitter 110 .
[0008] In the above-described method, a message bit of a previously transmitted frame is reused so that improvement of the overall throughput is achieved. However, if frame transmission fails, a parity bit is transmitted by reducing a coding rate stepwise. As such, transmission delay TD 1 becomes longer. Ultimately, due to the longer transmission delay, limitation of a transmission time on real-time data, such as voice, cannot be satisfied. In addition, data must be stored in a transmission buffer and a receiving buffer during several retransmissions, resulting in buffer overflow.
[0009] Basic technologies for hybrid ARQ are described in the articles “A Hybrid ARQ Scheme With Parity Retransmission for Error Control of Satellite Channels,” by S. Lin and P. S. Yu, IEEE Transaction on Communications, Vol. 30, pp. 1701-1719, July 1982, “Hybrid ARQ Protocol for Real-time ATM Services in Broadband Radio Access Networks,” by C. W. Ahn, W. S. Kang, CH. Kang and C G. Kang, IEEE TENCON 99, Vol. 2, pp. 1379-1382, 1999 and “Simple Hybrid Type II ARQ Technique Using Soft Output Information,” by P. Coulton, C. Tanriover, B. Wright and B. Honary IEE Electronic letters, Vol. 36, No.20, pp. 1716-1717, September 2000.
SUMMARY OF THE INVENTION
[0010] The present invention provides an adaptive hybrid automatic repeat request (ARQ) method and apparatus that minimize transmission delay by measuring an error degree of a frame in which error correction fails at a receiving terminal, adding the error degree to a NACK message, transmitting the NACK message to a transmitting terminal, and retransmitting a parity bit in accordance with the error degree at the transmitting terminal.
[0011] The present invention also provides a method of transmitting data in an adaptive hybrid ARQ system by which a parity bit in accordance with an error degree added to a NACK message transmitted from a receiving terminal is generated and retransmitted.
[0012] The present invention also provides a method of receiving data in an adaptive hybrid ARQ system by which as a result of channel decoding of a data frame transmitted from a transmitting terminal, an error degree of a frame in which error correction fails is measured and transmitted to the transmitting terminal together with a NACK message.
[0013] According to an aspect of the present invention, an adaptive hybrid automatic repeat request method comprises: (a) transmitting a data frame including a data bit and a parity bit that are channel-coded using a predetermined initial coding rate; (b) receiving the data frame, performing channel decoding of the received data frame, and when an error exists in the channel-decoded data frame, correcting the error; (c) when there is no error in the channel-decoded data frame or the error is corrected, transmitting an acknowledgement message to a transmitting terminal; (d) when the error of the channel-decoded data frame is not corrected, measuring an error degree of a corresponding frame and transmitting a negative acknowledgement message to which the measured error degree is added, to the transmitting terminal; (e) transmitting a parity frame that is generated by performing channel coding of a parity bit corresponding to a parity level determined in accordance with the error degree added to the negative acknowledgement message; and (f) combining the retransmitted parity bit with a data bit of a data frame in which error correction fails and performing channel decoding and error correction.
[0014] According to another aspect of the present invention, an adaptive hybrid automatic repeat request apparatus comprises: a transmitter for transmitting a data frame comprising a data bit and a parity bit that are channel-coded using a predetermined initial coding rate, and retransmitting a parity frame that is generated by performing channel coding of a parity bit corresponding to a parity level determined in accordance with the error degree added to the negative acknowledgement message transmitted via a predetermined channel; and a receiving unit for receiving a data frame transmitted from the transmitter, performing channel decoding of the received data frame, when there is no error in the channel-decoded data frame or the error is corrected, transmitting an acknowledgement message to the transmitter, when the error of the channel-decoded data frame is not corrected, measuring an error degree of a corresponding frame and transmitting a negative acknowledgement message to which the measured error degree is added, to the transmitter, combining a parity bit that corresponds to the negative acknowledgement message and is retransmitted from the transmitter, with a data bit of a data frame in which error correction fails, and performing channel decoding and error correction.
[0015] According to yet another aspect of the present invention, a method of transmitting data in an adaptive hybrid automatic repeat request system comprises: (a) transmitting a data frame comprising a data bit and a parity bit that are channel-coded using a predetermined initial coding rate; and (b) retransmitting a parity frame that is generated by performing channel coding of a parity bit corresponding to a parity level determined in accordance with the error degree added to the negative acknowledgement message transmitted from a receiving terminal.
[0016] The method of transmitting data further comprises: (c) monitoring the error degree that is added to the negative acknowledgement message and transmitted to the transmitting terminal, for a predetermined amount of time and predicting a channel environment; and (d) adjusting the initial coding rate in consideration of the predicted channel environment.
[0017] According to another aspect of the present invention, a method of receiving data in an adaptive hybrid automatic repeat request system comprises: (a) transmitting a data frame comprising a data bit and a parity bit that are channel-coded using a predetermined initial coding rate; (b) receiving the data frame, performing channel decoding of the received data frame, and when an error exists in the channel-decoded data frame, correcting the error; (c) when there is no error in the channel-decoded data frame or the error is corrected, transmitting an acknowledgement message to a transmitting terminal; (d) when the error of the channel-decoded data frame is not corrected, measuring an error degree of a corresponding frame and transmitting a negative acknowledgement message to which the measured error degree is added, to the transmitting terminal; (e) transmitting a parity frame that is generated by performing channel coding of a parity bit corresponding to a parity level determined in accordance with the error degree added to the negative acknowledgement message; and (f) combining the retransmitted parity bit with a data bit of a data frame in which error correction fails and performing channel decoding and error correction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The above and other aspects and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
[0019] [0019]FIG. 1 illustrates a conventional hybrid type-II ARQ method;
[0020] [0020]FIG. 2 illustrates an adaptive hybrid ARQ method according to the present invention;
[0021] [0021]FIG. 3 is a block diagram illustrating a structure of an adaptive hybrid ARQ system according to an embodiment of the present invention;
[0022] [0022]FIG. 4 is a flowchart illustrating a method of transmitting data in an adaptive hybrid ARQ system according to an embodiment of the present invention;
[0023] [0023]FIG. 5 is a flowchart illustrating a method of receiving data in an adaptive hybrid ARQ system according to an embodiment of the present invention;
[0024] [0024]FIG. 6 is a graph showing a retransmission success probability according to a coding rate when the adaptive hybrid ARQ method according to the present invention is used;
[0025] [0025]FIG. 7 is a graph showing the distribution of reliability according to signal to noise ratio (SNR);
[0026] [0026]FIG. 8 is a graph showing the relation of the transmission success probability and the number of transmission when the adaptive hybrid ARQ method according to the present invention is used;
[0027] [0027]FIG. 9 is a graph showing the relation of SNR and the average number of transmission in each case where the adaptive hybrid ARQ method according to the present invention and the conventional hybrid type-II ARQ method are used; and
[0028] [0028]FIG. 10 is a graph showing the relation of the SNR and an average throughput in each case where the adaptive hybrid ARQ method according to the present invention and the conventional hybrid type-II ARQ method are used.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Preferred embodiments of the present invention will be described in detail herein below, examples of which are illustrated in the accompanying drawings.
[0030] An adaptive hybrid ARQ method according to the present invention will be described below with reference to FIG. 2. In FIG. 2, a transmitter 210 transmits a data frame comprising a parity bit 221 and a data bit 222 that are generated by performing channel coding using a code having a high coding rate during initial transmission. A receiver 230 receives the data frame and performs channel decoding. When an error occurs during channel decoding and error correction fails, the receiver 230 measures an error degree of a frame in which error correction fails, and transmits a NACK message 223 to which the measured error degree D 224 is added, to the transmitter 210 . When receiving the NACK message 223 , the transmitter 210 interprets the error degree D 224 from the NACK message 223 and transmits a parity frame 225 that is generated using a code having a coding rate determined in accordance with the error degree D 224 . The receiver 230 corrects an error that occurs in a data bit of a previous frame in which error correction fails, using the transmitted parity frame 225 . If error correction is successful, the receiver 230 transmits an ACK message 226 to the transmitter 210 . If error correction fails, the receiver 230 again measures the error degree D 224 and repeatedly performs step of transmitting the NACK message 223 to which the measured error degree D 224 is added, to the transmitter 210 .
[0031] When using the adaptive hybrid ARQ method, the number of retransmissions can be ensured to be 1 or less in a general additive white gaussian noise (AWGN) channel environment. Thus, transmission delay TD 2 can be considerably reduced in comparison with transmission delay TD 1 that is generated in the conventional hybrid type-II ARQ method illustrated in FIG. 1.
[0032] [0032]FIG. 3 is a block diagram illustrating an adaptive hybrid ARQ system according to an embodiment of the present invention. In the adaptive hybrid ARQ system, a transmitter 310 includes a channel coding unit 311 , a first transmitting unit 312 , a first receiving unit 313 , an error degree interpretation unit 314 , and a parity level determination unit 315 . Further, a receiver 330 includes a second receiving unit 331 , a channel decoding unit 332 , an error correction unit 333 , an error degree measurement unit 334 , a storage unit 335 , a NACK message generation unit 336 , and a second transmitting unit 337 .
[0033] In the transmitter 310 , the channel coding unit 311 performs channel coding of a data frame including a data bit and a parity bit using an initial coding rate by using a code in which soft iterative decoding can be performed, such as a low density parity check (LDPC) code, a turbo code, or a convolutional code; and performs channel coding of a parity frame including a parity bit of a parity level that is determined by the parity level determination unit 315 which will be described later. More details for LDPC code are described in the articles “On The Design of Low-Density Parity-Check Codes Within 0.0045 dB of the Shannon Limit,” by S. Y. Chung, J. G. D. Formey, T. Richardson and R. Urbanke, IEEE Commun. Lett., Vol. 5, pp. 58-60, February 2001 and “Near Shannon Limit Performance of Low Density Parity Check Codes,” by D. J. C. MacKay and R. Neal, Electron Letters, Vol. 33, pp. 457-8, March 1997. In addition, more details for soft iterative decoding are described in the book “Constrained Coding and Soft Iterative Decoding,” by J. L. Fan, Kluwer academic publishers, 2001.
[0034] The first transmitting unit 312 includes a transmission buffer (not shown), which adds header information on a corresponding frame to the data frame or the parity frame that is channel-coded by the channel coding unit 311 to then transmit the data frame or the parity frame to the receiver 330 via an AWGN channel.
[0035] The first receiving unit 313 receives an ACK message or a NACK message that is transmitted from the transmitter 330 . When receiving the ACK message, the first receiving unit 313 transmits information on the ACK message to the channel coding unit 311 . When receiving the NACK message, the first receiving unit 313 transmits the NACK message to the error degree interpretation unit 314 . The error degree interpretation unit 314 extracts the error degree from the NACK message transmitted from the first receiving unit 313 to interpret the error degree.
[0036] The parity level determination unit 315 stores a table that maps the error degree and the parity level in advance, and determines the level of a parity, for example, a parity for Forward Error Correction (FEC), from the mapping table, in accordance with the error degree interpreted by the error degree interpretation unit 314 to provide the determined parity level to the channel coding unit 311 . An example of a FEC level used in the mapping table is shown in Table 1 as below.
TABLE 1 FEC level Parity bit number LDPC code FEC-1 250 (750, 500, 3) FEC-2 500 (1000, 500, 3) FEC-3 1,000 (1500, 500, 3) FEC-4 1,000 × 2 (1500, 500, 3) FEC-5 1,000 × 4 (1500, 500, 3)
[0037] The mapping table shown in Table 1 illustrates an example in which data is coded using a LDPC code (625, 500, 3), i.e., a code rate Rc 4/5, during initial transmission. As an FEC level is increased, the number of parity bits is increased twice. In particular, at FEC levels such as FEC-4 and FEC-5, parity bit numbers 1000×2 and 1000×4, each formed of (1500, 500, 5), are transmitted. This is because several parity bits are simultaneously transmitted to minimize retransmission delay when an error exceeding an error correction capability occurs. FIG. 6 is a graph showing a retransmission success probability according to a parity at each FEC level in accordance with a reliability R, which is inversely proportional to the error degree. As the reliability R is reduced, a stronger parity is needed.
[0038] In the receiver 330 , the second receiving unit 331 includes a receiving buffer (not shown) and receives the data frame or the parity frame from the transmitter 310 via the AWGN channel. When receiving a data frame from the second receiving unit 331 , the channel decoding unit 332 decodes a data bit of the data frame using a channel code used in the transmitter 310 . When receiving the parity frame from the second receiving unit 331 , the channel decoding unit 332 combines the parity frame with the data bit of a previous frame in which error correction fails, to perform channel decoding.
[0039] The error correction unit 333 determines whether an error occurs in the data bit that is channel-decoded by the channel decoding unit 332 . To this end, an error detection code C 0 may be used in the same manner as the conventional type-II ARQ method when a turbo code or a convolutional code is used for encoding. Further, an LDPC itself having a function of error detection may be used when an LDPC code is used for encoding. When the error occurs, the error correction unit 333 performs error correction of the decoded data bit using the parity bit of the data frame and determines whether error correction is successful. When error correction is successful or an error does not occur in the channel-decoded data bit, the error correction unit 333 generates an ACK message and transmits the ACK message to the transmitter 310 via the second transmitting unit 337 .
[0040] However, when it is determined in the error correction unit 333 that error correction fails, the error degree measurement unit 334 measures an error degree of the data frame in which error correction fails. In an embodiment in which a LDPC code is used, the value of posterior probability is used. This will be described in greater detail herein below.
[0041] A soft decoding algorithm in which the reliability of each bit is gradually improved as an iterative decoding operation is performed, is used in the LDPC code. As the iterative decoding operation is performed, the value of posterior probability is changed to ‘1’ or ‘0’. Thus, as the value of posterior probability is closer to ‘0.5’, the unreliability of a receiving side is increased and the reliability of a corresponding bit is lowered. Based on this concept, reliability Ri, which is inversely proportional to an error degree of an i-th frame, can be obtained by Equation 1.
R i = 1 k ∑ j = 1 k 0.5 - P ij ( 1 )
[0042] In equation 1, k represents the length of a message bit, and P ij represents the value of posterior probability of a j-th message bit of the i-th frame. According to equation 1, 0≦R i ≦0.5. In addition, as the value of R i is increased, the reliability of the message bit of the corresponding frame is improved. In the distribution of the reliability, that is error degree, R in the AWGN channel, as an SNR is reduced, an average value of R is reduced, as illustrated in FIG. 7. The graph in FIG. 7 shows iterative decoding performed thirty times using a coding rate (625, 500, 3).
[0043] The storage unit 335 adds the message bit of the data frame in which error correction fails, to the value of posterior probability to store the added message bit. Subsequently, when the second receiving unit 331 receives the parity frame from the transmitter 310 , the storage unit 335 provides the stored message bit to the channel decoding unit 332 .
[0044] The NACK message generation unit 336 generates a NACK message to which the error degree measured by the error degree measurement unit 334 is added, and transmits the NACK message to the transmitter 310 via the second transmitting unit 337 .
[0045] [0045]FIG. 4 is a flowchart illustrating a method of transmitting data in an adaptive hybrid ARQ system according to an embodiment of the present invention. Referring to FIG. 4, in steps 41 and 42 , channel coding of a data frame including a data bit and a parity bit using an initial coding rate is performed by using a code in which soft output iterative decoding can be performed, such as a LDPC code, a turbo code, or a convolutional code. In step 43 , the channel-coded data frame is transmitted to a receiving terminal via an AWGN channel.
[0046] In step 44 , whether a NACK message is received from a receiving terminal is determined. When the NACK message is not received form the receiving terminal, that is, when an ACK message is received from the receiving terminal, in step 43 , a next data frame is transmitted to the receiving terminal. However, when it is determined in step 44 that the NACK message is received, in step 45 , an error degree added to the NACK message is extracted and interpreted.
[0047] In step 46 , a parity level is determined in accordance with the error degree interpreted in step 45 , channel coding of a parity frame is performed in accordance with the determined parity level. In step 47 , a corresponding parity frame is transmitted to the receiving terminal. In order to determine the parity level in accordance with the error degree in step 46 , preferably, a transmission delay time and throughput that are to be ensured should be considered. For example, in the case of a traffic in which short transmission delay should be ensured like in voice, an error should be corrected in second retransmission. Thus, preferably, the traffic is mapped to have a high error correction probability, for example, a retransmission success probability between 1 and 0.9 inclusive. However, in this case, a possibility that a stronger parity than a parity needed to correct an error that occurs actually is transmitted is increased and may cause overload. As such, preferably, the traffic in which throughput should be considered is mapped using a comparatively low error correction probability.
[0048] The error degree added to the NACK message transmitted from the receiver 330 can be monitored for a predetermined amount of time, so that a channel environment can be expected and an initial coding rate can be adjusted considering the expected channel environment.
[0049] [0049]FIG. 5 is a flowchart illustrating a method of receiving data in an adaptive hybrid ARQ system according to an embodiment of the present invention. Referring to FIG. 5, in step 51 , the second receiving unit 331 receives a frame from the transmitter 310 via a transmission channel. In step 52 , the type of a frame is determined from header information.
[0050] When the type of the frame is a data frame, step 55 is performed. When the type of the frame is a parity frame, in step 53 , a data bit in which error correction fails is loaded from the storage unit 335 , and in step 54 , the loaded data bit is combined with a parity bit of the received parity frame.
[0051] In step 55 , the channel decoding unit 332 and the error correction unit 333 perform channel decoding and error correction using the data frame received in step 51 or the data bit and the parity bit that are combined in step 54 , respectively. In step 56 , whether error correction is successful is determined.
[0052] When error correction is successful, in step 57 , the error correction unit 333 generates an ACK message to transmit the ACK message to the transmitter 310 via the second transmitting unit 337 . When error correction fails, in step 58 , the error degree measurement unit 334 measures an error degree by the above-mentioned equation 1. In step 59 , the NACK message generation unit 336 generates a NACK message to which the measured error degree is added. The generated NACK message is transmitted to the transmitter 310 via the second transmitting unit 337 .
[0053] In step 60 , the data bit of the data frame in which error correction fails is stored in the storage unit 335 . Subsequently, when a corresponding parity frame is transmitted from the transmitter 310 , the parity frame is provided to the channel decoding unit 332 .
[0054] Next, the effects of the adaptive hybrid ARQ method according to the present invention and the conventional hybrid type II ARQ method will be described with reference to FIGS. 9 and 10. The graphs shown in FIGS. 9 and 10 illustrate a simulation result where an LDPC code is used and iterative decoding is performed thirty times in an AWGN channel environment.
[0055] [0055]FIG. 9 is a graph showing the relation of SNR and the average number of transmissions in each case where a retransmission success probability is set to 50% (R50), 70% (R70), and 95% (R95) using the adaptive hybrid ARQ method according to the present invention and the conventional hybrid type-II ARQ method HARQ2. In the case of HARQ2, as a channel environment is deteriorated, that is, as the SNR is reduced, the average number of transmission for each frame is continuously increased. However, in the case of the adaptive hybrid ARQ method according to the present invention, most errors are corrected during second transmission regardless of the retransmission success probability. In particular, as illustrated in FIGS. 6 and 8, if a second transmission success probability is set to 95% (R95) when the error degree is mapped to the parity level, during second transmission, i.e., during retransmission, an error over 98% as average is corrected. Even when the second transmission success probability is set to 70% (R70) or 50% (R50) in consideration of throughput, an error over 85% as average is corrected. Even when an error occurs in services that are sensitive in transmission delay, such as voice traffic, an error correction can be performed within the fastest time by means of mapping of the error degree and the parity level based on a high retransmission success probability.
[0056] [0056]FIG. 10 is a graph showing the relation of the SNR and an average throughput in each case where a retransmission success probability is set to 50% (R50), 70% (R70), and 95% (R95) using the adaptive hybrid ARQ method according to the present invention and the conventional hybrid type-II ARQ method. Referring to FIG. 10, when the state of a channel is good, that is, when the SNR is large, there is no specific difference between the present invention and prior art. When a channel environment is deteriorated, in the case of HARQ2, the number of transmissions for each frame is increased, such that a parity bit transmitted during a procedure reaching a parity level that can correct an error occurring in initial transmission, causes overload and leads to reduced throughput. On the other hand, in three cases in which the adaptive hybrid ARQ method according to the present invention is used, that is, in cases of R50, R75, and R90, throughput is improved. In the case of a general data traffic, it is preferable to consider throughput as well as a retransmission success probability. Thus, a probability that a burdensome parity may be transmitted can be reduced by means of mapping of the error degree and the parity level based on a low retransmission success probability.
[0057] The present invention can also be embodied as a computer readable code on a computer readable recording media. The computer readable recording media include all types of recording devices in which data that can be read by a computer system are stored, such as ROMs, RAMs, CD-ROMs, magnetic tapes, floppy discs, optical data storage units, and carrier waves (for example, transmission via the Internet). Also, the computer readable recording media are distributed over a network-connected computer system and can be stored and executed by computer readable codes. In addition, a functional program, a code, and code segments can be easily inferred by programmers in the technical field to which the present invention pertains.
[0058] As described above, in the adaptive hybrid ARQ system, at the receiving terminal, the error degree of the message bit is measured using the value of posterior probability of the message bit that is generated through a decoding operation and the NACK message to which the measured error degree is added is transmitted to the transmitting terminal. At the transmitting terminal, the parity level is determined in accordance with the error degree of the message bit contained in the NACK message, and the parity frame that is channel-decoded in accordance with the parity level is transmitted to the receiving terminal, such that when the channel environment is deteriorated or rapidly changed and the condition of a communications channel cannot be expected, the adaptive hybrid ARQ system can operate adaptively and the number of retransmission and transmission delay can be remarkably reduced.
[0059] In addition, the adaptive hybrid ARQ system can be embodied by adding only an error degree determination routine of the receiving terminal and a corresponding parity generation routine of the transmitting terminal to a general hybrid type II ARQ protocol, such that backward compatibility with an existing hybrid type II ARQ system can be ensured. As such, the adaptive hybrid ARQ system can be used in a high-speed downlink packet access (HSDPA) system, which is a high-speed packet data transmission system used in IMT-2000.
[0060] Further, the error degree measured from the frame in which error correction fails, is used for general adaptive channel coding. The change of an error degree value added to the NACK message transmitted from the receiving terminal is monitored, such that the change of the channel is predicted and a data coding rate at the transmitting terminal is adjusted. Accordingly, a layer that takes charge of channel coding can operate independently with respect to other layers.
[0061] While this invention has been particularly shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. | An adaptive hybrid automatic repeat request system and method, which comprise (a) transmitting a data frame comprised of a data bit and a parity bit that are channel-coded using a predetermined initial coding rate; (b) receiving the data frame, performing channel decoding of the received data frame, and when an error exists in the channel-decoded data frame, correcting the error; (c) when there is no error in the channel-decoded data frame or the error is corrected, transmitting an ACK message to a transmitting terminal; (d) when the error of the channel-decoded data frame is not corrected, measuring an error degree of a corresponding frame and transmitting a NACK message to which the measured error degree is added, to the transmitting terminal; (e) retransmitting a parity frame that is generated by performing channel coding of a parity bit corresponding to a parity level determined in accordance with the error degree added to the NACK message; and (f) combining the retransmitted parity bit with a data bit of a data frame in which error correction fails and performing channel decoding and error correction. | 7 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of PCT application PCT/EP2004/010026, filed Sep. 8, 2004 by inventor Johann Philipp Dilo, and claims priority to German application DE 103 46 472.7, filed Oct. 2, 2003.
FIELD OF THE INVENTION
The invention relates to a method of manufacturing a textile and, more particularly, to a method of using needles for reinforcing a fiber web or fleece.
BACKGROUND
To achieve a sufficient strength in very thin fiber fleeces, as they are for instance used in the field of sanitation, a very tight compound of the fibers forming the fleece is required. So-called “needling” technology is one possible type of manufacturing technology used in producing fleeces from fiber webs and for reinforcing fleeces. Such technology generally requires that the fiber web or the fleece be needled with a very high density of stitches.
Thin fiber webs and fiber fleeces of the above-mentioned kind are very sensitive and fragile before being needled. When subjected to low mechanical load they easily lose their coherence and break. Their processing in needle looms is therefore very delicate, which is why relatively high limits were formerly set to a reduction of the surface weight of the needled products, which did not comply with the desires of the users.
Sensitivity of the processed material also resulted in the fact that the working speeds have been relatively low and the fleece web had to be processed using a very large number of needle stitches per surface unit of the product, which caused a corresponding low productivity.
Thus, it is an object of the present invention to provide a method by which a gentle processing of fiber webs and fiber fleeces is possible, which improves the production and quality of very thin and light-weight needled products.
SUMMARY OF THE INVENTION
To solve this object the invention provides a method of reinforcing a textile web of a fiber web or fiber fleece by needling in a plurality of directly successive steps, in which the web is needled alternatingly from both sides and in the state of the needles stitched into the web is moved only by a needle movement extending in the longitudinal extension of the web, each needle grasping merely a single fiber during the stitching-in movement of the needle, the fiber having a gauge of 1 to 2 dtex.
By the use of a high needle density in the individual needling steps, the invention achieves a high productivity. When using needle boards of a width of, for example, 350 to 400 mm, the method enables an equipment density of up to 40,000 needles per meter needle board length. The pitch of the needles is then, for example, 3 mm or less, which requires the use of special needles of small diameter. The production speed may reach 200 m/min at working widths of up to 6 m, only to mention examples. Light-weight products with surface weight of up to 10 g/m 2 and less can be manufactured, for example, of a single carding web. As a result, the fibers may be relatively fine, down to approximately 1 dtex. Fiber fibrils of less than 1 dtex can also be processed. Corresponding stitching densities may be approximately 2,500 per cm 2 , and they may possibly also be higher. In the case of a needle equipment density of the above-mentioned kind and an effective horizontal stroke of the needles of 1 cm, the fiber fleece web must be needled by six needle boards each on both sides to achieve th mentioned stitching density.
The processing of such light-weight products, as mentioned above, is enabled by the measures of the invention, according to which the web is moved in the stitched-in state of the needles within the needle looms only by a movement of the needles which extends in the longitudinal direction of the web. Since the needles of the two needling units, which are combined in a double needle loom, alternatingly stitch into the fiber web, i.e., the working cycles of these needling units are mutually offset by 180°, an almost continuous transport of the fiber fleece web through the needles takes place by the effect of the needles only. Furthermore, this mode of operation enables a dense equipment of the needle boards, since the needles of two opposing needle boards will not collide with one another.
Thus, tension acting from external transport means does substantially not act on the web, said tension being likely to be braked by the needles in the state stitched into web. Rather, the needle units themselves are responsible for the feed of the web.
Depending on the type of processed web, a modification in length of the web by the individual needling processes may occur during operation of the needle loom. To avoid upsetting or drafts of the web between the individual needle looms, the speeds with which the individual needle looms transport the web must be adapted to one another in a suitable manner. In the case of identical horizontal and vertical strokes of the needle bars per stitching movement in the individual needle looms, the adaptation of the speed may be implemented by modification of the stitching frequencies of the individual needle looms. This solution is especially advantageous if the horizontal stroke and the vertical stroke of the needle bars are fixedly coupled with one another. However, it is also possible, with the horizontal and vertical strokes of the individual needle looms being identical, to make the stitching depths of the needles different, since thereby the time period during which the needles are stitched into the web and transport same by the horizontal movement of the needles is influenced, which has a certain effect on the transport stroke in the horizontal direction per needle stitch. If needle looms of the type described in EP 0 892 102 B1 are used, the horizontal stroke per needle stitch can to a large extent be influenced by a respective control of the needle looms.
The co-movement of the needles with the web in the stitched-in state of the needles is known from DE 196 15 697 A1. There, said co-movement has the aim to avoid a deterioration of the surface of the web, which could be caused by a draft if the transport speed of the fiber fleece by the needle loom is too high. The speed of the horizontal drive component of the needle bar is adapted to the supply speed at which the web of supply, and draft means is moved through the needle loom. By comparison, the present invention utilizes the oscillating needle movement components extending in the longitudinal direction of the web to actively transport the web without the need of further transport means. By use of the invention, not only single-layer but also multi-layer fiber fleece webs directly supplied by the carding device can be reinforced to form a fleece. In addition, it is also possible to reinforce cross-lapped fleeces by using the present method. Aerodynamically laid fiber webs, which are possibly very thin, can also be reinforced by the present needling method.
The fibers may for instance be cotton fibers, staple lengths of 20 mm to 40 mm can also be taken into consideration, as well as endless fibers of spunbonded fleeces, and smooth fibers and textured fibers may form the webs which may be processed by the aid of the invention.
When processing the webs, needles are used whose notches are so fine that they grip a single fiber only of a gauge of 1 to 2 dtex. Such a needle for instance has a shaft diameter of 1.85 mm and reduces its diameter across its length in two steps to 0.5 mm. The notch depth of the needles is about 0.02 mm, and only one notch is formed at an edge of the needle. Since only a single fiber is pressed by the needle into the fleece and the needle has an extremely small diameter, stitching holes do not remain visible. By this reason and due to the high stitching density, a mark-free surface of the needled product is achieved having a high abrasion resistance.
The distance of the notches from the needle tip shall preferably be small to be able to operate at a small needle stroke. An exemplary preferred distance between the notch and the needle tip is 2 mm. A small needle stroke allows greater working speeds. It can also operated with fork needles or crown needles, e.g. with fork widths and fork depths of 2/100 mm. The needles may have standard lengths of 2.5, 3 or 3.5 inches, they may possibly also be shorter which is in favor of their stability and the weight reduction. A weight reduction is also advantageously enhanced if the needles consist of plastics. A possibly small diameter of the needle shaft improves the strength of the needle since then more board material remains at an identical needle equipment density.
Since a high needle equipment density may cause the needle boards to become very heavy, needles of plastics can also be taken into consideration whose weight is approximately ⅛ of the weight of steel needles. To prevent wobbling of the needle boards on the needle bars carrying same, the needle boards may be attached at the needle bar in a pre-tensed manner under small elastic deformation, as described, for example, in DE 102 38 063 A1. Such technology also enables the use of very wide needle boards.
It may also be advantageous to utilize a lamellar downholder, which consists of a slotted plate at which a plurality of lamellae arranged in parallel transversely to the longitudinal extension of the plate are formed. In this manner a downholder plate can be realized, which on the one hand has a small thickness in the slot area and which is not very prone to clog by fiber flight, but which on the other hand has a great stability at low weight. With lamellae directed towards the fleece web to be needled, this downholder may also be used in reversed fashion, such as by use as a stitching support. Such a downholder complies with the fact that due to the low needle shaft diameter the needles tend to bend more than thick needles. A lamellar downholder facilitates threading of the needles into the slots of the plate carrying the lamellae or even makes threading completely dispensable if the needles do not leave the slots in the plate during their entire movement stroke.
An alternative to the use of a plurality of needle looms disposed one behind the other and through which a fiber fleece is successively passed, is a system operative to pass the fleece several times back and forth through a single needle loom and to process fleece in such several stages by using this needle loom, wherein the needle boards can be changed between the individual cycles, if it shall be needled differently in the different processing stages, for example with different needles and different needling equipment densities.
By the use of the present method, fleeces that are smooth on both sides can be manufactured, wherein the stitching depths of the needles may decrease from processing step, i.e. needling unit, to processing step, i.e. the next needling unit. Thus, the fibers, needled by the needles through the needle web and which project from the web on the side opposite the stitching side, are pushed back into the web through the needling from the other side of the web. As a result, and by the aid of the step-wise reduction of the stitching depth, it can finally be achieved that fibers don't project anymore from the web. The double-needling technique, in which, in a needling zone, the web is needled either simultaneously or alternatingly from both sides, effects a doubling of the stitching depth on small spade.
In another aspect, it is also possible to produce hairy fleeces in which fibers project on one side. Such fleeces may, for example, be used for laminating onto a support, wherein the hairs promote the fixing of the fleece on the support.
Furthermore, it is possible by the aid of the invention to manufacture light fleeces with a structured surface, such as wiping cloths which have a pattern of holes stitched therein. Such wiping cloths are favored in households because of their capability to absorb dirt. For this purpose only one respective working process, with suitable smooth needled of an enlarged shaft diameter and a small equipment density of the needle board, must be introduced into the process. Due to the resilient return ability of the fibers, which causes a closing of the holes generated, such a process may be carried out in several stages with needles having a gradually increasing diameter, wherein the alignment of the holes of the semi-finished product with respect to the needles of the successive processing stage must be taken into consideration. By the aid of modern synchronization means this can easily be achieved. The use of a brush belt as a stitching support, which is guided through all processing stages, is also advantageous in this case, since the fleece favorably adheres on the brush belt and thus keeps its position on the support. After forming the holes, a thermal fixing may take place in that the perforated material is conducted through a rotary sieve furnace or through a flat belt drying furnace to achieve a thermo-fusion of the fibers at their intersecting points if they consist of a suitable material, e.g. a thermoplastic material.
Other structures and methods may be utilized. The needling on a grate or on a slotted plate or lamellar plate as stitching support, particularly by using needles with several notches per edge or several edges with notches and a higher notch depth, enables a structure of the fleece that takes place on both sides, if it is needled from both sides of the fleece. Fiber bundles are pulled or pushed out of the pre-reinforced fleece and are transported to the fleece surface. If a multi-arrangement of needle looms is used, this structuring is carried out in the last needle looms or the last needle loom of the line of needle looms or in a separate working step within a single loom, which is operated outside the machine aline for the purpose of patterning and structuring.
Depending on the feed of the web or per stroke and depending on the needle arrangement in the needle board, many different known patterns may be manufactured, such as longitudinal strips, transverse strips, diagonals or stitching patterns, etc.
It is important that at least the horizontal drives, that are associated with the different needle zones, are independent of one another, so that an adaptation to different transport speeds, which are caused by shortenings and prolongations of the web, may be achieved. If a synchronous vertical drive of all needle bars is not taken into consideration, which must be preferred in the sense of a possibly jerk-free transport of the fiber fleece web through the device, it can also be taken into consideration to influence the transport speeds that are caused by the individual needle looms by changing the stroke frequencies of the individual needle looms.
The foregoing summary does not limit the invention, which is defined by the attached claims. Similarly, neither the Title nor the Abstract is to be taken as limiting in any way the scope of the disclosed invention.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIGS. 1 and 2 in combination show an installation for manufacturing a needled fiber fleece web, wherein:
FIG. 1 shows an aerodynamic fleece former with supply, infeed and pickup, a transfer means and the inlet portion of a multi-stage needling installation; and,
FIG. 2 shows further needle looms of a needling installation.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
An exemplary system and method will now be described with reference to the device for reinforcing a fleece web, as shown in the drawing figures.
FIG. 1 shows an aerodynamic fleece former with supply, infeed and pickup, a transfer means and the inlet portion of a multi-stage needling installation, whereas FIG. 2 shows further needle looms of a needling installation. Instead of an aerodynamic fleece former, a roller card, a card or other web or fleece generator may be provided.
The installation of FIGS. 1 and 2 includes a fiber supplier 1 , which is connected via an infeed 2 with an aerodynamic fleece former 3 . From the fleece former 3 a transfer means 4 , which includes an endlessly revolving transport belt 5 , leads to the inlet portions of a needling installation 6 , which includes a plurality of needle looms. The transport belt 5 is confronted in the inlet area of the needling installation 6 with an endlessly revolving compression belt 7 , which serves for compressing a fiber fleece web 8 discharged from the roller card 3 and disposed on the endlessly revolving transport belt 5 .
A plurality of double needle looms 9 are arranged within the needling installation 6 , with the needle bars 10 alternatingly needling the fiber fleece web 8 from top and being schematically shown by hatched triangles. The needle bars 10 each carry a needle board densely equipped with needles, or a needle board group (not shown) densely equipped with needles. Only the drive motors 91 for the vertical stitching drive as well as horizontal drive units 11 of the needle looms 9 are schematically shown, such horizontal drive units 11 being coupled to the needle bars 10 through connecting rods 12 to provide the needle bar with a horizontal reciprocating movement component extending in parallel to the extension direction of the fiber fleece web 8 . The coupling between the connecting rods 12 and the needle bars 10 is not shown for reasons of clarity. For details, reference can be made, by way of example, to the aforementioned DE 196 15 697 A1 and to EP 0 892 102 B1, wherein the latter also discloses means by which the infinitely variable change of the stroke size of the horizontal movement of the needle bars may be adjusted elegantly. In this context it must be noted that it is advantageous if the stitching depth of the needles can also be adjusted, since this determines the dwelling time during which the needles are in the state stitched into the fiber fleece. For further explanations in this context, reference again is made by example to DE 196 15 697 A1.
The arrangement of the needle bars 10 and their drives 11 and 91 is identical in all needle looms 9 . The vertical drives of the individual needle looms 9 may be independent of one another and may also be controllable independent of one another to be able to individually influence the stroke frequencies, by means of which the transport speeds of the fiber fleece web at the individual needle looms can be varied. However, they can also be driven synchronously with one another, particularly by a common drive means, which helps avoiding stretching and upsetting deformations of the fiber fleece web within needling installation. But then the horizontal drives should be adjustable individually in their stroke size to enable that local transport speed adaptations be made.
On the outlet side of the needle loom installation 6 an outlet roller pair 13 is arranged, which discharges the ready worked fiber fleece web, which is now designated as final product by 81 , from the installation.
In the needle loom installation 6 , two double needle looms 9 may be combined in one common machine frame to form a twin unit, which has common upper and lower stitching supports (not shown) for the web to be processed. All upper needle bars, i.e., the upper needle bar groups of the twin arrangement, may be driven commonly, and the same applies to all lower needle bars.
Since the horizontal drives 11 for the needle bars 10 require a certain space, the gaps Z between adjoining twin units, where the horizontal drives are accommodated, are each bridged by endlessly revolving transport belts 14 , which support the processed fiber fleece web 8 from below so that it does not sag by its own weight and be thereby possibly stretched in an undesired manner. As an alternative, smooth support plates of a small surface friction can be taken into consideration over which the fiber fleece web can easily slip.
Since the web 8 is needled from both sides and the invention therefore uses double needle looms in which in a needling zone two needle units needling against one another oppose and whose needles alternatingly stitch into the fiber fleece web, the stitching supports on both sides of the fiber fleece web, against which the latter is pressed by the needle movement, are lamella grates with longitudinally extending lots, or slotted plates, whose slots enable the horizontal movement of the needles for the transport of the fiber fleece web 8 in the state stitched into same. Details are not shown, but reference may be made in this respect to the documents mentioned above, again by example. The use of lamella grates is known per se in the needling technology, particularly when forming pole loops on needle felts that are, for instance, used as flooring.
The needles may be arranged on the needle boards in packages, wherein packages are offset seen in the longitudinal direction transversely with respect to one another by less than one needle pitch to increase the stitching density on the fiber fleece web. The slots in a slot plate used as stitching support must then be offset as well with respect to one another in the transverse direction. It is also possible to adjust the lateral guide on he individual needle looms in adaptation to one another in a manner that the stitches generated by the needles of a following needle loom are offset in the fiber fleece web in the transverse direction with respect to the stitches which are generated in the same fiber fleece web by the needles of a preceding needle loom.
The horizontal strokes, which the individual horizontal drives 11 must carry out, must be adjustable depending on the properties of the fiber fleece web. As already mentioned, EP 0 892 102 B1 discloses means by which the horizontal stroke can infinitely be varied also during operation of the machine. As an alternative, a change of the stroke frequency can also be implemented. The stretching or shrinking of the fiber fleece web 8 possible occurring by the processing can, for instance, be determined in a contact-less manner by the aid of electronic cameras and autocorrelation of the images taken by same, and by the aid of these images the horizontal drives can be set. The means required for this purpose are not shown in the drawing figures for reason of clarity. It is clear that such means can be provided on each needle loom where the fiber fleece web may be subjected to changes, wherein a central control unit may be provided for the entire installation.
While the principles of the invention have been shown and described in connection with specific embodiments, it is to be understood that such embodiments are by way of example and are not limiting. Consequently, variations and modifications commensurate with the above teachings, and with the skill and knowledge of the relevant art, are within the scope of the present invention. The embodiments described herein are intended to illustrate best modes known of practicing the invention and to enable others skilled in the art to utilize the invention in such, or other embodiments and with various modifications required by the particular application(s) or use(s) of the present invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art. | A system and method for reinforcing a textile web of a fiber web or a fiber fleece by needling in a plurality of directly successive steps are provided, in which the web is needed from both sides with a high needle density in an alternating manner and in the state of the needles stitched into the web is transported through a movement of the needles which extends in the longitudinal direction of the web, where each needle in a stitching-in movement grasps merely a single fiber, having a gauge of 1 to 2 dtex, from the web. By the aid of the invention very thin fleeces can be produced without damaging same during their processing. | 3 |
SUMMARY OF THE INVENTION
A machine for pleating or smocking a fabric or other sheet material by passing it between elongated intermeshed toothed rollers onto needles which are supported by the rollers has incorporated into it means for preventing flexing of the rollers at the delivery side of the machine, thereby increasing the width of material that can be processed. Bobbins are provided on the machine for holding the thread for each needle, and means are provided for tensioning the thread passed from each bobbin to a needle.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the front of the machine showing the first set of rollers encountered by the material;
FIG. 2 is a perspective view of the rear of the machine showing the second set of rollers, the bobbins and means for tensioning the thread passing from each bobbin;
FIG. 3 is a sectional view taken on line 3--3 of FIG. 1, and
FIG. 4 is an end view of the machine.
DESCRIPTION OF THE INVENTION
A pleating or smocking machine incorporating the improved means provided by the invention is disclosed in the drawings and comprises a base 2 which supports two spaced parallel vertical end members 4,6. The end members, which are of improved, novel and useful structure which will be described, provide journal bearings for the ends of the shafts of a first pair of toothed rollers 10, 12 and a second pair of toothed rollers 14, 16. The axes of the four rollers are parallel, and the rollers 10, 12 of the first pair are positioned at the input side of the machine, and therefore first receive the material fed to the machine while the rollers of the second pair are positioned on the delivery side of the first pair.
The rollers of the first pair are so positioned that roller 10 is above roller 12 with the teeth of the two rollers intermeshed, while the rollers of the second pair are so positioned that roller 14 is above roller 16 with their teeth intermeshed, and the teeth of upper roller 14 of the second pair are also intermeshed with those of lower roller 12 of the first pair. The intermeshing of the rollers of each pair and of the rollers 12, 14 is sufficiently loose to permit the material being pleated to pass easily between the intermeshed teeth of the rollers.
Each roller is preferably of unitary construction from end to end, and the teeth of each roller are provided at spaced points along its length with a circumferential groove, each groove of each roller lying in the same plane transverse of the axes of the rollers as corresponding grooves of the other three rollers, the co-planar grooves being referred to as a set of grooves and being indicated at 20, 22, 24, 26 in the rollers 10, 12, 14, 16 respectively.
The bottoms 28 of the grooves of each set of grooves lie on a generally S-shaped cfurve and thus provide a supporting base for a generally S-shaped needle A having its pointed end adjacent the point of entry of the sheet material B between the rollers of the first pair, as particularly shown in FIG. 3, and having its eye end positioned on the delivery side of the second pair of rollers 14, 16. The eye of each needle receives a length of thread C on which the pleated or gathered part D of the fabric is received. When so positioned the concaved lower surface 30 at the leading end part of the needle rests on the upwardly facing convex upper surfaces 28a of the bottoms of the groove in roller 12, and the downwardly and rearwardly facing surface 32 at the trailing end of the needle rests on the forwardly facing bottom surfaces of the grooves of roller 14.
In the operation of the machine, each needle is subjected to the force of gravity and the force exerted by the moving rollers and material urging the needle toward the delivery end of the machine. The force of gravity is balanced by interaction between the groove bottom surfaces of roller 12 and the correspondingly shaped surfaces of the needles which rest on these groove surfaces. The lateral force on each needle is balanced by interaction between the groove bottom surfaces of roller 14 and the correspondingly shaped surface 32 of each needle, which engage the groove surfaces of roller 14.
The operation of pleating the material consists in offering its leading end to the throat of the roller pair 10, 12 and rotating the rollers to draw the material between the pair. The material envelopes the profile of a tooth of the roller 10 and as rotation continues the material is formed to the profile of the roller 10, as shown in FIG. 3, by being pressed into contact with the roller profile by the teeth of the roller 12, a series of pleats being thus formed in the material. As the pleats are formed they are impaled on the points of the needles, and as the material is progressively passed through the roller pair 10,12 the pleats in succession pass along the S-bend of the needle while still enveloping the teeth of the roller 10. As described, the roller 14 is engaged with the roller 12, and as the pleats move along the needles they pass in succession between the engaging teeth of these rollers and the reverse pleats formed between two original pleats became transferred on to the teeth of the roller 14 where they are retained by the bending of the needles in the direction away from the roller 12 and between the roller pair 14, 16. Continued rotation passes the pleats between the roller pair 14, 16 on to the straight trailing end part of each needle, and the pleats are finally discharged by passing off the trailing ends of the needles and on to the threads C.
The result of the described construction is that each needle is maintained in a floating condition between the rollers, so that the material B can pass relatively over the needles from points to trailing ends and on to the threads C while each needle is constrained against bodily movement relatively to the rollers both vertically and in the direction of the length of the needle, and is stabilised in the plane in which it is curved.
The roller 10 is arranged to be driven by means such as a crank handle 40 connected to the shaft of roller 10, and the drive is transmitted to the other rollers of both pairs by reason of the fact that the teeth of the rollers are intermeshed.
In the operation of a machine of the described type and construction the pleating or smocking of the material and its passage along the needles produces forces of considerable magnitude on the rollers in the direction of the delivery end of the machine, which is the direction of the arrows shown in FIG. 3, and it will be seen that the force on roller 14 is directed at an angle of approximately 40° above the horizontal and that the force exerted on roller 16 is exerted at an angle of approximately 70° below the horizontal, both in the direction of movement of the pleated material from the machine. These forces have limited the possible number of needles in existing machines, as the forces cause flexing of the rollers 14, 16 in the directions described. Such flexing adversely affects the operation of the machine and limits the number of needles which may be used to about 16 needles for a total dimension of about 6 inches of length of the rollers. This has, of course, imposed a severe restriction on the utility of machines of this type.
Means are provided by the invention which permit a major increase in the number of needles which may be incorporated in a machine, thereby increasing the range of its utility by increasing the width of fabric which may be processed. The preferred means, as shown in the drawings, comprise, first, a rod 50 extending between and supported by the end members 4, 6 adjacent the roller 14 and disposed with respect to that roller in such a way that the axes of the roller 14 and rod 50 lie on the line positioned approximately 40° above the horizontal as shown in FIG. 3. A sleeve 52 preferably formed of a synthetic plastic material such as polyethylene is mounted on this rod adjacent the mid-point of the roller 14 with its periphery in engagement with the outer surface of the roller. A second rod 60 extends between and is supported by the end members and is positioned so that its axis and the axis of roller 16 lie on the line positioned approximately 70° below the horizontal, as shown in FIG. 3. A sleeve 62 formed of a synthetic plastic material, such as polyethelene, is mounted on this rod adjacent the midpoint of the roller with its periphery in engagement with the roller. The sleeves 52, 62 do not necessarily extend throughout the length of the rod on which they are respectively mounted, and in the preferred embodiment of the invention each is approximately 3 to 4 inches in length and positioned at the longitudinal center of the rollers 14 and 16, respectively. The rods 50 and 60 are preferably supported in the end members for rotation, thereby eliminating any friction between each sleeve and the roller on which it bears.
Means are also provided by the invention for incorporating into the machine means for storing the thread supplied to each needle, and for producing in each thread a tension which causes each thread to be guided directly from the storage means to the needle, thereby preventing any tangling between threads. Such means comprise a rod 70 which is positioned at the lower part of the machine below the pleating rollers and the ends of which are received within slots 72, 74 in the end members 4, 6 respectively, whereby the rod may be removed and replaced. A plurality of thread bobbins or spools 80 are mounted along the length of this rod and held in position by any suitable means, the number of spools being preferably equal to the number of needles on the machine, and on each spool there is wound the thread to be supplied to one of the needles, the thread on each spool being preferably directed to the needle immediately above it.
Means are provided by the invention for tensioning each thread between its storage spool and the needle to which it is supplied, and such means comprises an elongated extension spring 90 which is mounted between and supported at its ends by the end members 4, 6 in a position adjacent and preferably below the spools 80. This spring comprises closely adjacent coils, and the thread from each spool is directed and positioned between adjacent coils and then led to a needle. The coils press on each thread and thereby restrain its movement and produce on it a slight tension which insures that the thread will travel in a straight path and will not become entangled with other threads.
The rollers 10, 12, 16 and rod 60 are preferably permanently and rotatably supported in the end members. The roller 14, however, is preferably removably supported in the end members by having its two end shafts movably received within inclined slots 100 in the end members. A hold-down plate 102 is provided on each end member for maintaining each end of the roller and rod 50, in the slot, and these plates may be held in place by screws. | The disclosure relates broadly to sewing machines and provides a machine for pleating a fabric or other sheet material by passing it between intermeshed toothed rollers which produce pleats and deliver the material onto needles which are supported by the rollers. | 3 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to a ventilation hood with a safety system for use with a cooktop. More particularly, the invention relates to a ventilation hood with a safety system designed to substantially reduce the possibility of a fire occurring in the ventilation hood and ductwork thereof, as well as reducing humidity resulting from steam generated by the operation of the cooktop. The invention further relates to a combination of a ventilation hood and cooktop system, as well as a method of operation of a ventilation hood and a cooktop.
[0002] A number of ventilation hood control units are known for reducing the spread of smoke resulting from cooking operations on cooktops, as well as for removing humidity caused by steam resulting from cooking on the cooktop.
[0003] One known system provides a control or regulating device for a stove which activates, deactivates, controls and regulates the heat energy of cooking zones of the stove in dependence upon the resulting cooking steam. The control device and corresponding sensor of such a system is installed in the ventilation hood associated with the stove. Such a system is primarily focused on controlling the level of steam detected, to control operation of the cooking zones and not the ventilation fan. The makers of the system list as one of its advantages achieving a substantial savings of energy.
[0004] Another prior art system proposes a smart circuit device for a smoke exhauster for cooking. The circuit device includes a sensing circuit for sensing temperature and smoke. The motor of the fan and the exhauster is controlled to operate at a rotation speed conducive to reducing noise and save energy. The fan speed is varied in response to the quantity of smoke and is controlled by a fuzzy logic controller.
[0005] Yet still another system for a commercial or institutional kitchen provides that the volume rate of a cooking exhaust may be increased to improve the general comfort, health and safety conditions in the kitchen and the rest of the facility. More particularly, such a system senses a parameter in the ambient air environment such as temperature and/or gas level. Depending on the activity of the cooking units, the air control system causes the exhaust system to increase the volume rate to a higher volume rate to exhaust more air from the ambient air environment, thereby reducing the temperature in the facility to improve comfort and reduce load on an high volume air conditioning (HVAC) system.
[0006] While all of these systems provide advantages in reducing ambient smoke and/or steam for the purpose of providing a comfortable environment for persons using a cooktop, these conventional systems still fall short in providing an optimized arrangement designed to minimize fires occurring in ventilation hoods and cooktops.
[0007] More particularly, the use of cooktops in an incorrect manner contrary to a manufacturer's instructions can cause a fire. Many current gas cooktops have burners which can operate at energy levels of greater than 15,000 BTUs. Such cooktops include four to six burners and the simultaneous operation of multiple ones of these burners for a long period of time can overheat ventilation elements exhaust ducts.
[0008] The overheating of ventilation elements exhaust ducts is particularly of concern in circumstances in which such ventilation hoods and elements in ducts have accumulated oils and fat in the duct tubes thereof as such oils and fats are entrained with gases and/or vapors being drawn through the ventilation hood duct during cooking operations. If the heat conditions above the cooktop exceeds certain parameters such as may occur, for example, as a result of a flame, or through use of many of the high BTU burners at one time, a substantial portion of the heat generated may be drawn into the duct system and cause a fire as a result of, among other reasons, the ignition of the oils or fat accumulated in the duct tubes.
[0009] In accordance with the invention, there is provided a ventilation hood with a safety system, a combination of a ventilation hood with a cooktop and a method of controlling operation of a ventilation hood and cooktop, which avoids the problems of the previously discussed conventional systems, and which substantially reduces or eliminates the danger of fire occurring in the duct work of the ventilation hood as a result of operation of the cooktop.
BRIEF SUMMARY OF THE INVENTION
[0010] In accordance with one aspect of the invention, there is provided a ventilation hood with a safety system for use with a cooktop. The hood includes a duct structure for having air flow through the duct structure. A variable speed fan is associated with the duct structure for forcing air to flow from above the cooktop through the duct structure. A temperature sensor serves to sense the temperature above the cooktop and an alarming unit serves to provide at least one type of alarming indication. A controller unit is associated with the aforementioned elements for controlling operation of the fan and the alarming unit. The controller unit is configured for increasing the speed of the fan when in operation, and for activating the alarming unit to provide a first alarm indication upon the temperature above the cooktop reaching a first predetermined level, and for causing the alarming unit to provide a second alarm indication upon the temperature above the cooktop reaching a second (higher) predetermined temperature.
[0011] In accordance with one aspect of the present invention, the controller unit is also connected to a cooktop for controlling operation thereof. The controller unit is further programmed for causing the alarming unit to provide a third alarm indication upon the temperature above the cooktop reaching a third predetermined temperature and for shutting down the fan and the cooktop.
[0012] A method of operating a ventilation hood used with a cooktop includes providing a ventilation hood having a duct structure for having airflow therethrough. A temperature sensor is provided and serves to sense temperature above the cooktop. An alarming unit is also provided and serves to provide at least one type of alarm indication. A controller unit is provided which serves to control operation of the fan and alarming unit. The method involves sensing the temperature above the cooktop, increasing the speed of the fan and providing a first alarm indication upon the sensed temperature reaching a first predetermined level. A second alarm indication is provided upon the sensed temperature reaching a second predetermined (higher) level.
[0013] In accordance with a further aspect of the present invention, the controller unit is connected to a cooktop associated with the hood. The method further involves shutting off the cooktop and fan and providing a third alarm indication upon the sensed temperature reaching a third predetermined (even higher) level.
[0014] In accordance with yet another aspect of the present invention, the invention involves a combination of a ventilation hood and a cooktop including the features of the previously described ventilation hood as connected to the cooktop for controlling operation of the cooktop and the ventilation hood.
BRIEF DESCRIPTION OF THE DRAWING
[0015] FIG. 1 is a front elevational view in partial section of a ventilation hood safety system connected to a freestanding range that comprises a cooktop, and showing the various elements of the present invention; and
[0016] FIG. 2 is a temperature status table illustrating the various operating states of the system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] In accordance with the present invention, there is provided a ventilation hood 11 that includes a duct structure 13 and a variable speed fan 15 with a variable speed motor 17 and a plurality of associated fan blades 19 . The hood 11 also includes a temperature or heat sensor 21 and a steam or humidity sensor 23 , both connected to a controller unit 25 . Associated with the ventilation hood 11 is a free standing range 27 including an oven 29 , cooktop 31 including a plurality of burners 33 , and controls 35 for controlling operation of the oven 29 and the burners 33 . Also associated with the freestanding range 27 is an alarming unit including an alarm indicator 36 and an automatic control module 37 , which, along with the temperature sensor 21 and the humidity sensor 23 , is connected to the controller unit 25 .
[0018] The operation of the ventilation hood 11 and the cooktop 31 will hereinafter be described with reference to the temperature status table set forth in FIG. 2 in accordance with which the system, including the controller unit 25 and the module 37 , is programmed. Although the system of the present invention is described as being implemented via software programming, the same function can be provided by the appropriate hardware, as will be readily apparent to those of ordinary skill in the art. Such programming may be done in numerous ways through firmware, downloadable software, and other means as also will be readily apparent to those of skill in the art.
[0019] When at least one of the burners 33 of the cooktop 31 is turned on through the use of the controls 35 , the automatic control module 37 provides feedback to the controller unit 25 , whereupon the controller unit 25 activates the fan motor 17 to cause blades 19 of the fan 15 to rotate at a first normal operating speed. If the temperature above the cooktop 31 reaches a first predetermined level, as detected by the temperature sensor 21 , the controller unit 25 causes the fan 15 to increase its speed and issues an alarm signal through the module 37 . For example, if the first predetermined level of the temperature is deemed, purely for exemplary purposes, to be a temperature of between 100 degrees Fahrenheit (=one temperature unit) to 150 degrees Fahrenheit (=one and one-half temperature units), then the controller unit 25 may be controlled to cause the fan 15 to increase its speed when a temperature at the first predetermined level of the temperature is detected.
[0020] In a typical embodiment, the alarm signal can be activation of a signal lamp in the alarm indicator 36 of the module 37 , which serves as a warning of high temperature in or in proximity to the ventilation hood 11 .
[0021] If the temperature above the cooktop 31 continues to rise to a second temperature level, as detected by the temperature sensor 21 , then the controller unit 25 causes the module 37 to issue a second alarm signal, for example, through a sound generator in the alarm indicator 36 as an audible signal. For example, if the second predetermined level of the temperature is deemed, purely for exemplary purposes, to be a temperature of between 150 degrees Fahrenheit (=one and one-half temperature units) to 200 degrees Fahrenheit (=two temperature units), then the controller unit 25 may be controlled to cause the module 37 to issue a second alarm signal when a temperature at the second predetermined level of the temperature is detected.
[0022] In an alternative aspect, the module 37 could have a visual display in the alarm indicator 36 or separately therefrom, capable of displaying text messages, and instead of an audible signal, a text message can be provided, both of which serve as a warning of an increased danger of catching fire which then allows the operator of the cooktop 31 to make decisions about continuing cooking operations.
[0023] If the temperature continues to rise to a third predetermined temperature level, as detected by the temperature sensor 21 , then the controller unit 25 issues a signal to the fan motor 17 and to the module 37 which immediately shuts down the fan motor to avoid additional heat being drawn into the duct structure 13 , and also causes the module 37 to shut down the burners 33 on the cooktop 31 . A text message is then issued on the display of the module 11 indicating that the fan 15 and the burners 33 were shut down to avoid a fire. For example, if the third predetermined level of the temperature is deemed, purely for exemplary purposes, to be a temperature of between 200 degrees Fahrenheit (=two temperature units) to 250 degrees Fahrenheit (=two and one-half temperature units), then the controller unit 25 may be controlled to issue a signal to the fan motor 17 and to the module 37 which immediately shuts down the fan motor.
[0024] In a yet still further aspect, the ventilation hood 11 also includes a humidity or steam sensor 23 , which is connected to the controller unit 25 and serves to detect steam or humidity generated from operation of the cooktop 31 . Independent of the operation of the inventive safety system with respect to temperature, if the humidity or amount of steam rises to certain levels, the controller unit is also programmed to increase the speed of the variable speed motor 17 in a predetermined relationship to the amount of steam being generated as a result of operation of the cooktop 31 . Additionally, it can be provided in this humidity reaction approach that the temperature driven controls will always take priority and will override steam/humidity driven control.
[0025] While the various elements including the temperature sensor 21 , the humidity/steam sensor 23 , the module 37 , the fan motor 17 and the controller unit 25 are shown in a hardwired configuration, it will be readily apparent to those of ordinary skill in the art that these units need not be hardwired and can operate in communication with each other through various other alternative technologies, for example, such as through infrared signals, radio signals, etc.
[0026] Yet still further, while in one specific aspect the system is shown as providing an alarm with a signal lamp for warning of reaching the first temperature level, an audible signal also can be provided. Also both audio and visual alarms can be provide at each preset warning level, which can be different in intensity or tone, as will be readily apparent to those of ordinary skill in the art. Alternatively, visible display issuing text message can be employed to provide clear information to the user of the cooktop.
[0027] Thus, the present invention provides a ventilator hood safety system having a controller unit connected to a cooktop for controlling the operation thereof, and the controller unit is further programmed for causing an alarm unit to provide a third alarm indication and for shutting down the cooktop and the fan upon the temperature above the cooktop reaching a third predetermined temperature.
[0028] The present invention additionally provides a ventilator hood safety system having a humidity sensor for sensing the humidity resulting from steam in proximity to the hood, and associated with the controller unit for having the controller unit increase the speed of the fan in response to increasing humidity. Also, the safety system includes an alarming unit including a signal lamp, and arranged for operation the controller unit for providing the first alarm indication as activation of the signal lamp. The alarming unit may include a sound generator and is arranged for operation with the controller unit for providing the second alarm indication as an audible signal generated by the sound generator. Also, the alarming unit may include a signal lamp and a visual display which are arranged for operation with the controller unit for providing the first alarm indication as activation of the signal lamp, and the second alarm indication may display a text message on the visual display warning of the danger of fire.
[0029] Having thus generally described the invention, the same will become better understood from the independent claims as set forth in a non-limiting manner. | A ventilating hood and cooktop system includes safety components to reduce or eliminate the possibility of a fire in the ventilating hood. The system provides elements for sensing the temperature over the cooktop. When the temperature reaches a first predetermined level, the ventilation fan speed is increased. The system includes alarm warning elements which issue different signals depending on the temperature above the cooktop. If a maximum temperature is reached, the system shuts off the fan of the ventilating hood and shuts down the cooktop. | 5 |
BACKGROUND OF THE INVENTION
The invention is directed to a bracket for supporting an electric powered outboard motor, such as a so-called electric trolling motor, relative to a small marine vessel, such as a Hobie Cat catamaran, in order to provide propulsion during becalm conditions.
A motor bracket under the name "CHEETA MOTOR BRACKET" is provided as an accessory for Hobie Cat sailboats and is intended to propel the same when the wind disappears. The motor bracket assembles to the rear cross bar of the trampoline frame of the Hobie Cat catamaran or sailboat, and includes a support arm pivoted at one end to the motor bracket and carrying at an opposite end a transom member to which an electric motor can be secured. The support arm is retained in a horizontal position when the electric motor is in use and can be pivoted to lift the motor completely out of the water when not in use. A major disadvantage of this conventional motor bracket is that in both the use and non-use positions the motor is located at a position susceptible to being bumped or struck by an occupant which can cause damage to the occupant, the motor bracket, the motor or all three. In addition, this conventional motor bracket is limited strictly to supporting the electric motor and no provision is made for housing an associated D.C. battery at an unobtrusive location. Accordingly, it is not uncommon to see the D.C. electric battery lashed in a rather unsecured fashion by bungee cords or the like to one of the corners of the trampoline frame. Obviously, this location is dangerous to occupants seated upon the trampoline, and it is not uncommon to have a battery simply drop overboard, particularly should the sailboat flip under the influence of high wind or virtually any other adverse sailing conditions.
SUMMARY OF THE INVENTION
In keeping with the foregoing, the present invention is directed to a bracket for supporting both an electric powered outboard motor and an associated D.C. electric battery relative to a marine vessel, most specifically a sailboat, such as a Hobie Cat sailboat. However, the invention is equally applicable to utilization in conjunction with a boat driven by a gas powered outboard engine or an inboard engine. However, in keeping with the specific intent of the invention, the bracket supports both the electric powered outboard motor and the D.C. electric battery in an out-of-the-way position in both use and non-use positions thereby assuring that occupants upon the trampoline will not be injured no matter the sailing conditions or the attitude of the sailing craft.
The bracket of the invention preferably utilizes a vertical rearwardly opening channel and a pair of downwardly opening channels to embracingly receive an associated dolphin striker post and a dolphin striker rod, respectively, of the trampoline frame of a Hobie Cat catamaran. A single removable pin firmly secures the bracket relative to the dolphin striker post and the dolphin striker rod thus enabling the rapid assembly and disassembly of the bracket relative to the trampoline frame. The bracket also includes a generally vertically disposed transom plate to which the electric motor can be clamped. The transom plate is also mounted for vertical adjustment in another vertical channel to selectively vertically adjust the height of the electric motor.
The bracket also includes as an integral part thereof a housing for receiving and supporting an associated D.C. electric battery. In this fashion the battery and the electric motor are supported immediately adjacent each other and both are located unobtrusively generally below the trampoline in both use and non-use position of the electric motor. Accordingly, occupants upon the trampoline cannot be injured under wind or windless conditions of vessel movement because the bracket, the electric motor and the battery are located unobtrusively removed from the trampoline area and occupants supported thereupon.
With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary top perspective view of a marine vessel, specifically a Hobie Cat catamaran or sailboat, and illustrates the novel electric motor and battery bracket of the present invention supported adjacent a black front bow crossbar of the trampoline frame.
FIG. 2 is a fragmentary perspective view of the novel bracket of this invention viewed from the bow or front of the sailboat, and illustrates a D.C. electric battery and an electric trolling motor supported by the bracket with the electric trolling motor being in its in-use position.
FIG. 3 is a fragmentary rear elevational view of the bracket, and illustrates the manner in which the electric motor is secured to a transom plate of the bracket with the shaft of the electric motor aligned with the longitudinal center line of the sailboat and the axis of its mast.
FIG. 4 is a fragmentary top perspective view, and illustrates the accessibility of the rotatable speed control handle of the electric motor through the center lacing of the trampoline adjacent the black front crossbar.
FIG. 5 is fragmentary rear elevational view similar to FIG. 3, and illustrates the electric motor in its out-of-the-way or non-use position.
FIG. 6 is a fragmentary exploded perspective view of the bracket and a portion of the sailboat frame, and illustrates the bracket as including a platform for supporting the electric battery, channels for receiving the dolphin striker post and dolphin striker rod of the sailboat frame, and a vertically adjustable transom plate to which is clamped the electric motor.
FIG. 7 is a fragmentary perspective view similar to FIG. 6, and illustrates the bracket with the channels thereof receiving therein the dolphin striker post and the dolphin striker rod and a removable pin for maintaining the latter components in their assembled relationship.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A conventional marine vessel is illustrated in FIG. 1 of the drawings and is generally designated by the reference numeral 10. The marine vessel 10 is a conventional sailboat, such as a Hobie Cat catamaran or sailboat, which includes port and starboard hulls 11, 12; front port and back port corner castings 13, 14, respectively; front starboard and rear starboard corner castings 15, 16, respectively; a port side bar 17, a starboard side bar 18, a rear or stern crossbar 19 and a black cross bar 20. The side bars 17, 18 are conventionally connected between the respective castings 13, 14 and 15, 16, while the crossbars 19, 20 are conventionally connected between the respective castings 14, 16 and 13, 15 thereby collectively defining a trampoline frame 25 within which is a trampoline 26 defined by two trampoline portions 27, 28. A center gap or slot 30 between the trampoline portions 27, 28 is spanned by conventional center lacing 31 and similar stern lacing 32 spans a stern gap or slot 33 between the trampoline portions 27, 28 and the rear cross bar 19. A mast step 34 has secured thereto an end of a mast 35 which is stabilized by a plurality of shrouds 36. A rudder 37, 38 is pivotally connected to the respective hulls 11, 12, and the rudders 37, 38 are simultaneously conventionally manipulated by movement imparted to a tiller 39. A sheet (not shown) associated with the mast 35 provides the requisite reaction surface for sailing under the influence of the wind, but should the vessel become becalmed, a conventional D.C. electric motor or trolling motor 40 (FIGS. 1 through 5) can be utilized to provide propulsion in association with an electric direct current (D.C.) battery 45 through appropriate electrical conductors and alligator clips (not shown).
The electric motor 40 includes a propeller 41 connected to a shaft 42 which enters a lower housing 43 housing an electric motor (not shown) with associate wiring running through a tubular shaft 44 which is telescopically slidingly received in a sleeve 46 of a first member 47 which is pivotally connected at 48 to a second or clamping member 49 carrying clamping screws 50. The first and second members 47, 49, respectively, can be conventionally selectively adjusted in any one of a number of different positions between the in-use position shown in FIGS. 1 through 4 and the stored or out-of-the-way position shown in FIG. 5 through an appropriate spring detent mechanism (not shown) and a plurality of notches (unnumbered). An upper end portion of the tubular end shaft 44 is connected to an upper housing 51 from which projects a rotatable and generally extensible control handle 52 which normally can be rotated between "off" and "on" positions and several variable speed positions therebetween.
A bracket for supporting the electric powered outboard motor or trolling motor 40 and also for supporting the electric battery 45 relative to the marine vessel or sailboat 10 is generally designated by the reference numeral 60.
The bracket 60 is best illustrated in FIGS. 2, 5, 6 and 7 of the drawings and includes means 70 for supporting the D.C. battery 45 in the form of a housing defined by a rear wall 71, side walls 72, 73, a front wall 74 and a substantially horizontally disposed bottom wall, support surface or cantilevered platform 75. A conventional hold-down strap, bungee or the like 77 is utilized to securely hold down the battery 45 within the housing 70 upon the bottom wall or platform 75 thereof, as is readily apparent from FIG. 2 of the drawings.
The rear wall 71 of the bracket 60 includes first means 80 and second means 81, 82 in the form of respective vertically disposed rearwardly opening and horizontally disposed downwardly opening slots or channels which embrace two specific structural members of the trampoline frame 25, namely, a dolphin striker post DSP being and a dolphin striker rod DSR which are best illustrated in FIGS. 6 and 7 of the drawings. The dolphin striker post DSP and the dolphin striker rod DSR are conventional structures located at the front or bow portion of the frame 25 with the dolphin striker post DSP being generally axially aligned with the mast step 33 and the mast 35 and spanning the gap (unnumbered) between the black front crossbar 20 and the dolphin striker rod DSR. The generally vertically disposed rearwardly opening channel 80 is formed by a portion of the back wall 71 of the housing 70 and two vertically disposed spaced generally parallel plates 83, 84 welded to the rear wall 81 and having aligned circular openings 85, 86, respectively, therein. The generally horizontally disposed downwardly opening channels 81, 82 are formed by respective angle irons, each including a generally horizontally disposed web 87 welded to the rear wall 71 and a vertically depending web 88. As is most readily apparent from FIG. 7, the bracket 60 is assembled upon the frame 25 by moving the vertical channel 80 into embracing relationship to the dolphin striker post DSP and dropping the bracket 60 downwardly which allows the horizontal channels 81, 82 to embrace the dolphin striker rod DSR on opposite sides of the dolphin striker post DSP, as is clearly evident in FIG. 7. Means are provided in the form of a generally cylindrical pin 90 which can be slid through the openings 85, 86 in the manner shown in FIG. 7 to secure the bracket 60 in its in-use position.
The bracket 60 also includes means 100 in the form of a substantially vertically disposed supporting transom surface or plate which is cantilevered in a rearward direction for supportingly clampingly receiving the second member or clamping member 49 of the electric motor 40, as is readily apparent from FIGS. 3 and 5 of the drawings. Preferably, a wood or hard rubber plate 101 is carried by the transom plate 100 to provide an excellent gripping surface for assuring non-slippage/non-rotation of the screws 50 after the latter have been tightened.
The electric motor support means 100 further includes a forwardly projecting portion 102 having an opening (not shown). The forwardly projecting portion 102 is sandwiched between two vertical plates 103, 104 defining a vertical rearwardly opening channel 105 having a depth corresponding to the thickness of the forward plate portion 102. A forwardmost vertical edge (unnumbered) of the forward plate portion 102 rests against the rear wall 71 of the housing 70 and prevents the entirety of the outboard motor supporting means 100 from pivoting or cocking and assures only uni-directional vertical sliding motion under the guidance of a pair of aligned slots 110 formed in the plates 103, 104 in generally parallel relationship to each other. A threaded bolt 111 passes through the slots 110 and an opening in the forward plate portion 102. A wing nut 109 (FIG. 3) can be utilized to tighten the bolt 111 in any one of a plurality of selected positions along the length of the slots 110 to locate the transom plate 101 at a desired vertical position to accommodate electric motors of different designs, sizes and physical characteristics. In lieu of the pair of slots 110, a number of horizontally aligned vertically spaced openings can be provided in the plates 103, 104 to achieve step-adjustment of the transom plate 101.
OPERATION
Once the bracket 60 has been assembled to the frame 25, and more specifically to the dolphin striker post DSP and the dolphin striker rod DSR in the manner shown in FIG. 7, the D.C. electric motor 40 is simply clamped to the transom plate 101 in the manner clearly apparent from FIGS. 3 and 5 of the drawings. It should be particularly noted from FIGS. 3 and 5 of the drawings that the bracket 60, the battery 45 and the motor 40 each occupy a position beneath the frame 25 and beneath the trampoline 26 both when the motor 44 is in use (FIG. 3) and when the motor 40 is in its non-use or stored position (FIG. 5). Thus, a person (or persons) supported atop the trampoline 26 will never come into contact with the bracket 10, the motor 40 or the battery 45 whether under full sail (FIG. 5) or under electric power (FIG. 3), and irrespective of the inclination, orientation or attitude of the sailboat 10. Therefore, injury to occupants upon the trampoline is virtually totally eliminated because of the location of the bracket 60, the battery 45 and the motor 40 at all times beneath the frame 25 and the trampoline 26 thereof. Furthermore, when in use (FIG. 3), the shaft 44 is clamped in the position shown in FIG. 3 by a set screw (not shown) passing through the tubular portion 46 of the first member 47 which locks the motor 40 in the position shown in FIGS. 3 and 4. This is particularly important because the speed control handle 52 (FIG. 4) can be accessed through the center gap 30 and rotated by the occupant to initiate straightforward or straight rearward propulsion at a desired speed. Once the latter is accomplished, the occupant merely moves to the stern of the sailboat 10 and manipulates the tiller 39 to turn the sailboat 10 through the manipulation of the rudders 37, 38. Thus, the occupant manning the tiller 39 is positioned remote from the bracket 60 under both electric power or wind power, both thereby assuring through the remoteness of the occupant from the bracket 60 that damage or injury will not occur.
Although a preferred embodiment of the invention has been specifically illustrated and described herein, it is to be understood that minor variations may be made in the apparatus without departing from the spirit and scope of the invention, as defined the appended claims. | A bracket is provided for supporting an electric powered outboard motor, such as a trolling motor, and a battery relative to a small marine vessel, such as a Hobie Cat, in order to provide propulsion during becalm conditions. The motor and battery bracket includes a chamber for housing a D.C. electric battery and a transom plate projecting therefrom in a generally vertical plane to which an electric powered outboard motor or trolling motor can be clamped. The latter bracket is preferably constructed for vertical adjustment. A quick connect/disconnect coupling secures the bracket to structural members of the marine vessel, specifically to the dolphin striker post and dolphin striker rod of a Hobie Cat catamaran. | 5 |
TRADEMARKS
IBM® is a registered trademark of International Business Machines Corporation, Armonk, N.Y., U.S.A. S390, Z900 and z990 and other names used herein may be registered trademarks, trademarks or product names of International Business Machines Corporation or other companies.
BACKGROUND OF THE INVENTION
This invention relates to decimal floating point (DFP) numbers, and more particularly to converting from DFP numbers into scaled binary coded decimal (SBCD) floating point numbers.
DFP has been used in calculators for many years but for the first time it is becoming part of an IEEE standard (754R Floating Point Standard). The DFP formats, as defined by the IEEE 754R standard, include: a thirty-two bit single precision format, a sixty-four bit double precision format, and a one hundred and twenty eight bit extend precision format. This new standard provides the means for computer designers to develop specific operations that are optimized to this new standard. Prior to the standardization of the operands it was not possible to develop specific operations to accelerate these types of computations. For some commercial workloads, emulation of DFP operations in software can dominate the processing timing.
With the advent of the new standard and the increase in the use of decimal arithmetic operations for financial calculations, it becomes desirable to implement these operations at a high performance.
BRIEF SUMMARY OF THE INVENTION
Exemplary embodiments of the present invention include a system for converting from decimal floating point (DFP) into scaled binary coded decimal (SBCD). The system includes a mechanism for receiving a DFP number. The system also includes at least one of a mechanism for performing coefficient expansion on the DFP number to create a binary coded decimal (BCD) coefficient part of a SBCD number and a mechanism for performing exponent extraction on the DFP number to create an exponent part of the SBCD number.
Additional exemplary embodiments include a method for converting from DFP into SBCD. The method includes receiving a DFP number. The method also includes performing at least one of a coefficient expansion on the DFP number to create a coefficient part of a SBCD number and exponent extraction on the DFP number to create an exponent part of the SBCD number.
Further exemplary embodiments include a system for converting from DFP into SBCD. The system includes a mechanism for receiving a DFP number. The system also includes either a mechanism for performing coefficient expansion or a mechanism for performing exponent extraction. The mechanism for performing coefficient expansion creates a BCD coefficient part of the SBCD number from the DFP number. The mechanism for performing exponent extraction creates an exponent part of the SBCD number from the DFP number. The mechanism for performing coefficient expansion is implemented by double precision hardware. The DFP number is single precision, double precision or extended precision. The performing coefficient expansion includes determining if the DFP number is a special number, and setting a condition code if the DFP number is a special number. The performing exponent extraction includes determining if the DFP number is a special number and setting the exponent part of the SBCD to indicate that the SBCD number is a special number.
Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with advantages and features, refer to the description and to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is an exemplary hardware diagram for implementing the compression of a coefficient from BCD to DPD according to exemplary embodiments of the present invention;
FIG. 2 is a block diagram of a process for converting a 34 BCD digit coefficient into a quad precision DFP operand according to exemplary embodiments of the present invention;
FIG. 3 is an exemplary hardware diagram for converting the exponent portion of a SBCD number to a DFP number according to exemplary embodiments of the present invention;
FIG. 4 is an exemplary hardware diagram for implementing the expansion of a coefficient from DPD to BCD according to exemplary embodiments of the present invention;
FIG. 5 is a block diagram of converting a quad precision DFP operand into a 34 BCD digit coefficient according to exemplary embodiments of the present invention; and
FIG. 6 an exemplary hardware diagram for implementing the extract exponent portion of converting from a DFP number to a SBCD number according to exemplary embodiments of the present invention.
The detailed description explains the exemplary embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
Exemplary embodiments of the present invention include operations for converting a coefficient of a DFP number to and from SBCD. Embodiments support the three different DFP formats (single precision—32 bit, double precision—64 bit, and extended precision 128 bit). In addition, exemplary embodiments set condition codes that allow the processor to rapidly detect when the source operand contains invalid data or special numbers, such as: infinity, quiet Not-A-Number (qNaN) and signaling Not-A-Number (sNaN). Exemplary embodiments of the present invention also describe operations for extracting and setting the exponent field of the DFP numbers for the three different DFP formats. Special numbers are handled by these operations using a number format that is compatible between the insert and extract instructions. Conditions codes are set to allow the processor to rapidly detect when a special number has been processed.
Exemplary embodiments include both conversion from a SBCD number (includes both a BCD coefficient and a binary exponent) into a DFP number and conversion from a DFP number into a SBCD number. The conversion from a SBCD number into a DFP number includes a compression of the BCD coefficient and an insertion of the SBCD exponent into the DFP number. The conversion from a DFP number into a SBCD number includes both an expansion of the DFP coefficient into a BCD coefficient and an extraction of the DFP exponent into the SBCD binary exponent.
Three different formats for a SBCD number are shown below in Table 1. The term SBCD number as used herein refers to a number that includes both a coefficient represented in BCD and an exponent represented in binary as well as an optional one bit sign field.
TABLE 1
SBCD Number Formats
NUMBER OF BITS IN EACH FIELD
FORMAT
Sign
Exponent
Coefficient
Single Precision
1
8
28
(7 digits)
Double Precision
1
10
64
(16 digits)
Extended Precision
1
14
136
(34 digits)
The three different formats for a DFP number are shown in Table 2 below. The sign field (labeled “S” in Table 2) indicates the sign of the operand, the combination field (labeled “C” in Table 2) contains the upper most significant digit (MSD) of the coefficient and the two most significant exponent bits encoded into a five bit coded format, the biased exponent continuation field (labeled “BEC” in Table 2) contains all but the two most significant bits of the exponent, and the coefficient continuation field (labeled “CC” in Table 2) contains all but the MSD of the coefficient in densely packed decimal (DPD) format.
TABLE 2
DFP Number Formats
NUMBER OF BITS IN EACH FIELD
FORMAT
S
C
BEC
CC
Single Precision
1
5
6
20
Double Precision
1
5
8
50
Extended Precision
1
5
12
110
As described previously, the combination field contains the upper MSD of the coefficient and the two most significant exponent bits encoded in a five bit coded format. Table 3, below, shows this five bit coding as described in the IEEE 754R standard where d 0 , d 1 , d 2 , d 3 are from the BCD coding for the MSD of the coefficient and b 0 , b 1 are the two most significant bits of the exponent.
TABLE 3
Coding of the Combination Field
Condition
Combination Field Coding
MSD = 0 to 7
b 0 , b 1 , d 1 , d 2 , d 3
MSD = 8 or 9
1, 1, b 0 , b 1 , d 3
Infinity
1, 1, 1, 1, 0
NaN
1, 1, 1, 1, 1
The combination field is utilized by exemplary embodiments to quickly recognize special numbers such as, but not limited to: qNaN, sNaN and infinity values. Special numbers can be detected by examining the digits in the combination field.
Compression of the Coefficient (BCD to DFP)
The compression operation primarily deals with the combination field which contains the most significant digit of the coefficient data (along with the most significant two bits of the exponent data) and the coefficient continuation field which contains the remaining 7, 15 or 33 BCD digits of the coefficient compressed into 20, 50 or 110 DPD bits depending on the target DFP format. The compression operation takes the BCD coefficient and creates a DPD coefficient for storage in the DFP number and generates a 5-bit combination field from the value based on the most significant BCD digit of the coefficient. This is also referred to herein as a compress from BCD (CBCDR).
The CBCDR operation may be implemented as a computer instruction that takes 16 BCD coefficient digits from the source operand and compresses the right most 15 digits into DPD bits and writes them to the right most 50 bits of the target register. The upper most digit is encoded into the combination field assuming an exponent value of zero and is written to the target register. The sign field and bits 6 to 13 of the target register (BEC for double precision operands) are positive and zero respectively. If the source register contains invalid BCD numerical codes then condition code one is set, otherwise condition code zero is set. Setting the condition code based on valid decimal data prevents the need for extra instructions specifically to verify the source data and saves a significant number of cycles and instructions for a typical processor.
FIG. 1 depicts an exemplary hardware diagram for implementing the compression of a coefficient from BCD into DFP (i.e., a CBCDR instruction) according to exemplary embodiments of the present invention. FIG. 1 includes a 16 digit BCD coefficient 102 as input to a valid digit detect block 110 , a BCD to combination field encoder 108 and a plurality of BCD to DPD encoders 106 . The plurality of BCD to DPD encoders 106 is also referred to herein as one bank of DPD to BCD encoders. Condition codes 112 are set in response to determining if the BCD coefficient operand 102 is a valid BCD number. In exemplary embodiments, the condition code is set to zero if the SBCD coefficient 102 is a valid BCD number, and is set to one if the BCD coefficient 102 contains an invalid BCD number.
The BCD to DPD encoders 106 each compress three BCD digits (12 bits) of the BCD coefficient 102 into 10 bits of DPD. The compression is applied to all but the MSD of the SBCD coefficient 102 . For double precision numbers, the compressed coefficient is stored in the fifty least significant bits of the DFP number 104 a . The BCD to combination field encoder 108 creates the 5 digit combination field described previously based on the MSD of the coefficient of the SBCD number. The combination field is stored in the second through sixth bits of the DFP number 104 a.
For a double precision formatted operand, the 64-bit DFP number 104 a that is output from the processing depicted in FIG. 1 includes 64 bits with a sign bit in the most significant bit (bit 0 ), the combination field in the next five most significant bits (bits 1 - 5 ), a zero in the biased exponent continuation field (bits 6 - 13 ), and the compressed coefficient in the coefficient continuation field (bits 14 - 63 ).
As mentioned above, the CBCDR operation is designed for double precision DFP operands which are expected to be the most common operand used in workloads. However, these instructions may be utilized to process extended precision operands as well. The process for compressing a 34 digit BCD coefficient to an extended format DFP number is depicted in FIG. 2 .
The process for converting 34 digit BCD coefficient into a quad precision DFP operand includes a series of shift, merge, and CBCDR operations. The first source register 202 (the low order bits of the 34-digit BCD coefficient) on the left is compressed to 50 bits of DPD format and is written to a first intermediate register 208 on the right. The second source register 204 (digits 2 through 18 of the 34 digit BCD coefficient) is shifted one digit to the left and the MSD from the first source register 202 is merged into the vacated right most digit. This data is then compressed to 50 bits of DPD data and is written to a second intermediate register 210 .
Next, the third source register 206 is shifted until it is left aligned and two digits (digits 0 to 1) that were unprocessed in the second source register 204 are merged to the right of the shifted third source operand data. A final compression is done as described in reference to the CBCDR instruction such that the MSD is processed such that it is aligned with the combination field of the target register. The results are written to a third intermediate register 212 . The final step is to align the data in the intermediate registers 208 , 210 , 212 and merge it into a target register pair 214 with the sign bits and biased exponent continuation field set to positive and zero respectively.
The processing depicted by the arrows labeled 216 is the CBCDR operation described previously with respect to FIG. 1 . This processing may be performed by the same hardware/software instructions executing sequentially and/or by having three sets of the same hardware/software instructions executing in parallel to produce the results in the first intermediate register 208 , the second intermediate register 210 and the third intermediate register 212 . In addition, the same CBCDR operation may be utilized to compress a single precision formatted number. The same hardware (e.g., 64 bit hardware) and/or software (e.g., millicode) may be utilized to perform the compression for any of the three precisions specified by the IEEE 754R standard for decimal floating point numbers.
Insertion of the Exponent (BCD number to DFP)
The instructions for inserting the binary exponent from the SBCD number into the DFP number primarily deal with the combination field and the biased exponent continuation field which contains the remaining 6, 8, or 12 bits of exponent data, depending on the format. The three insert exponent instructions include insert exponent single precision, insert exponent double precision, and insert exponent extended precision. Each of these instructions read a binary integer from a source register whose value is the biased exponent that is to be inserted into the DFP number in the target register. The MSD of the coefficient encoded in the target register is read to determine how the combination field should be encoded. The combination field and exponent continuation fields are then updated. The updating sets the exponent value of the target DFP number in the target register to the value contained in the source register.
If the source register is negative (bit 0 =1) then the target register is to be updated with a special number. In exemplary embodiments, the least two significant bits are used to determine if the target register is updated with the value representing infinity (bits 62 : 63 =11′b), qNaN (bits 62 : 63 =10′b) or sNan (bit 62 =0′b).
FIG. 3 depicts an exemplary hardware diagram for implementing the exponent insertion for a conversion from a binary exponent part of a SBCD number into an exponent part of a DFP number according to exemplary embodiments of the present invention. FIG. 3 depicts a 64 bit binary exponent 302 , and the 64 bit DFP number 104 a output from the processing described in reference to FIG. 1 . The output from the processing depicted in FIG. 3 is an updated 64-bit DFP number 104 b that includes updates to the combination and biased exponent continuation fields. Operand bits 0 , 62 , and 63 of the 64 bit binary exponent 302 are input to a special number generator 306 to generate the special values infinity, qNaN and sNaN as previously discussed if the binary exponent is negative (bit 0 is a value of ‘1’). The combination field generator 308 receives 6 bits (bits 50 - 51 and 54 - 57 ) of the binary exponent 302 , the results from the special number generator 306 , the operand size 304 , and the DFP number 104 a . The combination field generator 308 generates bits 1 to 5 of the result (the combination field) and first bit of the exponent continuation field) and writes the result to the 64-bit DFP number 104 b . The processing in FIG. 3 also includes an exponent continuation field generator 310 for updating the biased exponent continuation field of the DFP number 104 b . In an exemplary embodiment, the output from the special number generator 306 is input to the exponent continuation field generator 310 . If the special number generator 306 indicates that the DFP number is a qNaN, then the exponent continuation field generator 310 overwrites the most significant bit of the exponent field (bit 6 ) with a “0”. If the special number generator 306 indicates that the DFP number is a sNaN, then the exponent continuation field generator 310 overwrites the most significant bit of the exponent field (bit 6 ) with a “1”.
Expansion of the Coefficient (DFP to BCD)
The expansion to BCD operation takes a double precision DFP number in a source register and converts the coefficient digits of the DFP number, stored as DPD and combination field, into a BCD coefficient which is written to a target register. If the source operand is a special number such as infinity, qNaN, or sNaN, a zero is written to the MSD of the target register and the condition codes may be set accordingly (infinity=1, qNaN=2, sNaN=3). This operation is also refereed to herein as an extract to BCD operation (EBCDR).
FIG. 4 depicts an exemplary hardware diagram for implementing the EBCDR process according to exemplary embodiments of the present invention. FIG. 4 includes the 64-bit DFP number 104 b as input to optional special number detector 406 , a combination field to BCD decoder 404 and to a plurality of DPD to BCD decoders 402 . Condition codes 112 are set in response to determining if the coefficient portion of the DFP number 104 b is a special number. In exemplary embodiments, the condition code is set to zero if the coefficient is normal, set to one if the coefficient is infinity, set to 2 if the coefficient is qNaN and set to 3 if the coefficient is sNaN.
The DPD to BCD decoders 402 each expand 10 bits of the DPD into three BCD digits (12 bits). The decoding is applied to all of the bits in the coefficient continuation field in the DFP number 104 b . For double precision numbers, the expanded SBCD coefficient continuation field is stored as the 15 least significant digits of the 16-digit BCD coefficient 102 . The combination field to BCD decoder 404 receives the 5 digit combination field 108 of the DFP number 104 b and creates the MSD of the BCD coefficient.
As mentioned above, the EBCDR operation is designed for double precision DFP operands which are expected to be the most common operand used in workloads. However, as depicted in FIG. 5 , these instructions may be utilized to process extended precision operands as well. The process depicted in FIG. 5 for converting a quad precision DFP number into a 34 digit BCD coefficient consists of a series of shift, merge, and EBCDR expansion steps.
The process depicted in FIG. 5 begins converting (e.g., using the EBCDR process depicted in FIG. 4 ) the low order 50 bits of the first source register 502 (low order 50-bits of a DFP extended precision operation) to 15 digits of BCD data in a first intermediate register 508 . The coefficient continuation field of the second source register 504 (high order 64-bits of a DFP extended precision operand) is left shifted 14 bits and the unprocessed bits in the first source register 502 are merged to the right of them. A second expansion instruction (e.g., an EBCDR) writes 15 more BCD digits to a second intermediate register 510 . The coefficient continuation field is then shifted 10 bits to the right and stored in the third source register 506 . The final expansion instruction (e.g., an EBCDR) writes the remaining 4 BCD digits to a third intermediate register 512 . Finally, the 34 BCD digits of data in the three intermediate registers 508 510 512 are aligned and merged into the three destination registers 514 allocated for this operation.
The processing depicted by the arrows labeled 516 is the EBCDR operation described previously with respect to FIG. 4 . This processing may be performed by the same hardware/software instructions executing sequentially and/or by having three sets of the same hardware/software instructions executing in parallel to produce the results in the first intermediate register 508 , the second intermediate register 510 and the third intermediate register 512 . In addition, the same EBCDR operation may be utilized to compress a single precision formatted number. The same hardware (e.g., 64 bit hardware) and/or software (e.g., millicode) may be utilized to perform the compression for any of the three precisions specified by the IEEE 754R standard for decimal floating point numbers.
Extraction of the Exponent (DFP to SBCD)
The exponent extract instructions (one for each format) read the upper double word of the DFP number from the source register. For single precision and double precision this contains the whole DFP number. For normal numbers, the operation extracts the biased exponent from the encoded combination field and the biased exponent continuation field and sets the condition code to zero. If the source DFP number is infinity, then the SBCD exponent is set to a minus one and condition code one is set. If the source DFP number is a qNaN, then the SBCD exponent is set to a minus two and condition code two is set. If the source DFP number is a sNaN, then the SBCD exponent is set to a minus three and condition code three is set. Using condition codes in this manner allows the processor to rapidly detect when a special number is processed and eliminates the need for special instructions to detect these special cases.
FIG. 6 depicts an exemplary hardware diagram for implementing the exponent extraction for a conversion from a DFP number 104 b into the binary exponent 302 . FIG. 6 depicts a 64-bit DFP number, or upper half of a DFP number for extended precision, 104 b and an operand size 304 as input. The special number detector 406 looks for the special numbers as described above based on the value of the combination field and first bit of the biased exponent continuation field. The special number detector 406 sets the condition codes 112 and outputs the status to an exponent extractor 602 . The exponent extractor 602 determines the binary exponent 302 based on the combination field and the biased exponent continuation field the operand size 304 and output from the special number detector 406 .
Exemplary embodiments of the present invention allow the processing described herein (coefficient compression, coefficient expansion, exponent insertion and exponent extraction) to be performed individually. For example, if the data set is known to contain identical exponent values (ie. for adding data values in a set known to be represented in pennies), then the extra processing and register usage required for extracting the exponent is not needed. Another example may be a routine used to convert a database from SBCD to DFP, no conversion process would be needed to convert DFP back to SBCD. Another example is to check for special values, only the extract exponent process is needed to obtain the necessary condition codes. The option to perform each conversion operation serially also allows the hardware required for the system to be reduced since the same intermediate registers may be used by all of the operations. This performance versus complexity tradeoff is important for hardware implementations where the area or power available for the required hardware may be limited.
Exemplary embodiments of the present invention provide four conversion operations that support the three IEEE 754R standard DFP formats. The operations include coefficient compression, coefficient expansion, exponent insertion and exponent extraction. Exemplary embodiments described herein may be utilized in a standard super-scalar microprocessor using minimal additional dataflow hardware. In addition, special numbers are detected and reported with the general case through result values and/or condition codes. Still further, invalid decimal data is reported through condition codes.
The capabilities of the present invention can be implemented in software, firmware, hardware or some combination thereof.
As one example, one or more aspects of the present invention can be included in an article of manufacture (e.g., one or more computer program products) having, for instance, computer usable media. The media has embodied therein, for instance, computer readable program code means for providing and facilitating the capabilities of the present invention. The article of manufacture can be included as a part of a computer system or sold separately.
Additionally, at least one program storage device readable by a machine, tangibly embodying at least one program of instructions executable by the machine to perform the capabilities of the present invention can be provided.
The diagrams depicted herein are just examples. There may be many variations to these diagrams or the steps (or operations) described therein without departing from the spirit of the invention. For instance, the steps may be performed in a differing order, or steps may be added, deleted or modified. All of these variations are considered a part of the claimed invention.
While the preferred embodiment to the invention has been described, it will be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the invention first described. | A system and method for converting from decimal floating point (DFP) into scaled binary coded decimal (SBCD). The system includes a mechanism for receiving a DFP number. The system also includes at least one of a mechanism for performing coefficient expansion on the DFP number to create a binary coded decimal (BCD) coefficient part of a SBCD number and a mechanism for performing exponent extraction on the DFP number to create an exponent part of the SBCD number. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a burner structure applicable to various types of combustion apparatuses such as a pulverized coal boiler.
[0003] This application is based on Japanese Patent Application No. 2006-303780, the content of which is incorporated herein by reference.
[0004] 2. Description of Related Art
[0005] Hitherto, boilers fired with a fuel powder, for example, pulverized coal or petroleum coke have been used.
[0006] To describe a burner structure employed in a pulverized coal boiler that is fired with pulverized coal, a burner is composed of a pulverized coal-air mixture system provided in the burner center and containing pulverized coal and a primary air, a secondary air system provided around the pulverized coal-air mixture system, and cooling air (tertiary air) systems optionally provided around or above and below the secondary air system.
[0007] FIG. 5 is a sectional view showing a pulverized coal burner structure of the related art.
[0008] A burner 10 of FIG. 5 is structured such that a secondary air path 12 as a secondary air system is provided around a pulverized coal-air mixture path 11 as a pulverized coal-air mixture system. In addition, a cooling air path 13 as a cooling air (tertiary air) system is provided above the secondary air path 12 .
[0009] Provided at furnace-side ends of the pulverized coal-air mixture 11 and the secondary air path 12 is a nozzle main body 17 that integrates a pulverized coal nozzle 14 and a secondary air nozzle 15 with a flame holder 16 provided at their tip ends. Further, a cooling air nozzle 18 is attached at the furnace-side end of the cooling air path 13 . The cooling air nozzle 18 functions to prevent a falling clinker from the upper part in the furnace from colliding against the burner 10 and to shield a flame radiation heat. In FIG. 5 , reference numeral 19 denotes a wind box.
[0010] In the thus-structured burner 10 , the following combustion method is employed. That is, a fuel and an air are supplied while the total amount of the primary air, the secondary air, and the tertiary air is set smaller than an ideal air amount relative to an amount of pulverized coal loaded to fire the burner as required by the regulations on nitrogen oxides (NOx). In this way, a main combustion zone is kept under a reducing atmosphere. Then, NOx generated upon burning the pulverized coal is reduced, after which an additional air is supplied from an additional air nozzle (not shown) provided on the downstream side of the main combustion zone for oxidation combustion. In this way, combustion is completed. Thus, enough air is supplied around a pulverized coal flow in the main combustion zone.
[0011] Further, in the burner 10 of the related art, the nozzle main body 17 is tiltable for controlling a steam temperature or an amount of NOx at the outlet as shown in FIG. 6 , but the cooling air nozzle 18 is fixed.
[0012] In addition, there is reported another structure that the entire nozzle inclusive of an air flow path corresponding to the above cooling air nozzle 18 is tiltable (see the Publication of the U.S. Pat. No. 6,260,491, for instance).
[0013] Recently, an ignition performance has been enhanced year by year along with improvements in the flame holder 16 . As a result, materials for the burner 10 are exposed to higher temperatures. On the other hand, if a flow rate of the cooling air supplied to the cooling air nozzle 18 is increased to increase a cooling ability, a combustion temperature lowers and causes an increase in unburned components. Thus, exhaust gas characteristics are deteriorated, so it is necessary to efficiently cool the nozzle main body 17 with a small amount of air.
[0014] Moreover, in the burner 10 of the related art, the nozzle main body 17 is only tiltable and the cooling air nozzle 18 is fixed, which causes a problem in that the tilted nozzle main body 17 is exposed to radiation heat.
[0015] On the other hand, in the structure where the entire nozzle is tiltable as disclosed in the Publication of U.S. Pat. No. 6,260,491, an air flow rate is determined in accordance with an air-flow-path area ratio, resulting in a problem in that an air flow rate cannot be adjusted during operation.
[0016] Further, the part corresponding to the cooling air nozzle 18 does not have a function of protecting the nozzle main body from a falling clinker or radiation heat, which situation might occurs in the case where a fuel powder such as pulverized coal is used. Therefore, this structure is disadvantageous from the viewpoint of ensuring a long component life.
[0017] In view of such circumstances, there is an increasing demand for a burner structure that is capable of adjusting an air flow rate and efficiently cooling a nozzle main body with a small amount of air, and takes an efficient countermeasure against a falling clinker or radiation heat.
BRIEF SUMMARY OF THE INVENTION
[0018] The present invention has been accomplished in view of the above circumstances, and it is an object of the present invention to provide a burner structure that is capable of adjusting an air flow rate and efficiently cooling a nozzle main body with a small amount of air, and takes an efficient countermeasure against a falling clinker or radiation heat.
[0019] The present invention adopts the following solutions with a view to attaining the above object.
[0020] A burner structure according to the present invention includes: a fuel-air mixture system provided in a burner central portion and supplying a mixture of a fuel and a primary air; a secondary air system provided around the fuel-air mixture system and supplying a secondary air; a cooling air system provided around or above and below the secondary air system and supplying a cooling air; a nozzle main body attached to furnace-side end portions of the fuel-air mixture system and the secondary air system in a tiltable form and provided with a flame holder at its tip end; and a cooling air nozzle attached to a furnace-side end portion of the cooling air system in a tiltable form.
[0021] According to the above burner structure, since the burner structure includes a nozzle main body attached to furnace-side end portions of the fuel-air mixture system and the secondary air system in a tiltable form and provided with a flame holder at its tip end, and a cooling air nozzle attached to a furnace-side end portion of the cooling air system in a tiltable form, the secondary air and the cooling air are independently supplied from different air supply systems. Hence, an air flow rate can be adjusted and controlled in each air supply system.
[0022] In the burner structure, it is preferred that a tip end position of the cooling air nozzle be substantially the same as a tip end position of the flame holder in a tiltable range of the nozzle main body and the cooling air nozzle because an influence of a falling clinker or radiation heat on the nozzle main body can be eradicated or suppressed.
[0023] In the burner structure, it is preferred that the cooling air nozzle include a canopy-like member for partitioning an inner portion of a tubular member, and a tip end of the canopy-like member be adjusted to substantially the same position as a tip end of the flame holder in a tiltable range of the nozzle main body and the cooling air nozzle because the cooling air nozzle can be made lightweight, and an influence of a falling clinker or radiation heat on the nozzle main body can be eradicated or suppressed.
[0024] In the burner structure, it is preferred that the cooling air nozzle be provided with a cooling fin because a cooling efficiency is improved.
[0025] Further, in the burner structure according to the present invention, it is preferred that axes of tilt of the nozzle main body and the cooling air nozzle coincide with each other because a tilting mechanism can be simplified.
[0026] In the burner structure, it is preferred that the cooling air nozzle be detachably attached to the nozzle main body because the cooling air nozzle can be replaced alone.
[0027] In this case, a flow rate of an air supplied to the cooling air and the secondary air is determined in accordance with a sectional area ratio, so a wind box structure can be simplified.
[0028] According to the burner structure of the present invention, it is possible to adjust an air flow rate and more efficiently cool a nozzle main body with a small amount of air, and protect a nozzle main body from a falling clinker or radiation heat.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0029] FIG. 1 is a sectional view of a burner structure according to a first embodiment of the present invention;
[0030] FIG. 2A is a sectional view of a burner structure according to a second embodiment of the present invention;
[0031] FIG. 2B shows the burner structure of the second embodiment and a cooling air nozzle as viewed from the front on the outlet side;
[0032] FIG. 3A is a sectional view of a burner structure according to a third embodiment of the present invention;
[0033] FIG. 3B shows the burner structure of the third embodiment and a burner as viewed from the front on the outlet side;
[0034] FIG. 4 is a sectional view of a modified example of the third embodiment of FIGS. 3A and 3B ;
[0035] FIG. 5 is a sectional view of a burner structure of the related art; and
[0036] FIG. 6 is a sectional view of the burner structure of the related art in a tilted form.
DETAILED DESCRIPTION OF THE INVENTION
[0037] Hereinafter, embodiments of a burner structure according to the present invention will be described with reference to the accompanying drawings.
First Embodiment
[0038] A burner structure according to a first embodiment of the present invention as shown in FIG. 1 is a pulverized coal burner used for a pulverized coal boiler fired with pulverized coal as a fuel.
[0039] This burner 10 A includes a pulverized coal-air mixture path 11 that is provided in the burner center as a fuel-air mixture system for supplying a pulverized coal-air mixture containing pulverized coal as a fuel and a combustion primary air. A secondary air path 12 as a secondary air system for supplying a combustion secondary air is provided around the pulverized coal-air mixture path 11 . In addition, a cooling air path 13 as a cooling air system for supplying a cooling tertiary air (hereinafter referred to as “cooling air”) is provided above the secondary air path 12 .
[0040] To take an example of the case where pulverized coal is used as a fuel, a pulverized coal-air mixture is set to about 80° C. and supplied to the pulverized coal-air mixture path 11 in the burner center. Moreover, a secondary air and a cooling air are set to about 300° C. to 350° C. and supplied to the secondary air path 12 and the cooling air path.
[0041] A nozzle main body 17 is attached to furnace-side end portions of the pulverized coal-air mixture path 11 and the secondary air path 12 , and a tilting mechanism (not shown) is provided, so the nozzle can be tilted to change a blowoff angle from a horizontal angle to a desired one. The nozzle main body 17 is completed by combining a pulverized coal nozzle 14 that ejects a pulverized coal-air mixture and a secondary air nozzle 15 that ejects a secondary air, and integrally attaching a flame holder 16 to tip ends of both the nozzles.
[0042] To describe the structure of the nozzle main body 17 in detail, the pulverized coal nozzle 14 has a tapered tube-like form, and the secondary air nozzle 15 similarly has a tapered tube-like form with a large diameter and is integrally provided around the pulverized coal nozzle 14 . The pulverized coal nozzle 14 and the secondary air nozzle 15 constitute a double-walled tube-like structure with a large diameter. Then, the flame holder 16 that has similarly a double-walled tube-like structure and increases its diameter toward an outlet at the tip end is integrally attached to tip ends of the pulverized coal nozzle 14 and the secondary air nozzle 15 .
[0043] A cooling air nozzle 18 is provided at a furnace-side end portion of the cooling air path 13 independently of the nozzle main body 17 . The cooling air nozzle 18 is provided with a tilting mechanism (not shown) similar to the nozzle main body 17 and thus can be tilted to change a blowoff angle from a horizontal angle to a desired one. The cooling air nozzle 18 has a tube-like shape, and it is preferred that its tip end position on the outlet side be substantially the same as that of the flame holder 16 in a tiltable range of the nozzle main body 17 and the cooling air nozzle 18 .
[0044] In the thus-structured burner 10 A, the cooling air path 13 for supplying a cooling air to the cooling air nozzle 18 is independent of the pulverized coal-air mixture path 11 and the secondary air path 12 , so a flow rate of the cooling air can be adjusted and controlled solely. To be specific, a flow rate of the cooling air can be controlled independently of a pulverized coal-air mixture or a secondary air by providing the cooling air path 13 with a flow rate adjusting part such as a damper.
[0045] As a result, a flow rate of the cooling air can be adjusted and controlled more precisely and finely than a conventional structure that determines an air flow rate in accordance with a path sectional area ratio. Hence, if a flow rate of the cooling air is optimized in accordance with operation conditions, the nozzle main body 17 can be efficiently cooled. In addition, the cooling air nozzle 18 is independent of the nozzle main body 17 , so if the cooling air nozzle needs to be replaced as a result of periodical checkup or the like, only the nozzle can be replaced.
[0046] Further, also in the case where the cooling air nozzle 18 is tilted to thereby tilt the nozzle main body 17 , if the cooling air nozzle 18 is tilted to the best position, a falling clinker adheres to the cooling air nozzle 18 first. Hence, it is possible to shield radiation heat with the cooling air nozzle as well as to prevent the clinker from adhering to the nozzle main body 17 , so the nozzle main body 17 is not directly exposed to radiation heat.
[0047] If the outlet-side tip end position of the cooling air nozzle 18 is substantially the same as a tip end position of the flame holder 16 in a tiltable range of the nozzle main body 17 and the cooling air nozzle 18 , the nozzle main body 17 can be protected from a clinker or radiation heat with higher reliability.
[0048] Incidentally, in the case of tilting the cooling air nozzle 18 to protect the nozzle main body 17 from a clinker or radiation heat, if axes of tilt of the cooling air nozzle 18 and the nozzle main body 17 coincide with each other, the structure can be simplified, for example, the tilting mechanism is shared. Here, the cooling air nozzle 18 and the nozzle main body 17 may be integrally formed so that both nozzles are always tilted to the same direction at the same time.
Second Embodiment
[0049] Referring next to FIGS. 2A and 2B , a burner structure according to a second embodiment of the present invention will be described. Here, the same components as those of the above embodiment are denoted by identical reference numerals, and detailed description thereof is omitted.
[0050] A burner 10 B of this embodiment includes cooling fins 20 provided inside a tube-like cooling air nozzle 18 A. The cooling fins 20 alternately protrude from an upper surface and a lower surface of the inner portion of the tube-like nozzle as shown in FIG. 2B , but the present invention is not limited to this structure. If the cooling air nozzle 18 A is provided with the cooling fins 20 in this way, a contact area with a cooling air is increased to improve a cooling efficiency. Incidentally, the cooling air nozzle 18 A is tiltable as in the above cooling air nozzle 18 .
Third Embodiment
[0051] Referring next to FIGS. 3A and 3B , a burner structure according to a third embodiment of the present invention will be described. Here, the same components as those of the above embodiments are denoted by identical reference numerals, and detailed description thereof is omitted.
[0052] A burner 10 C ( 10 D) of this embodiment includes a canopy-like member 21 of a plate shape, which partitions an inner portion of a tube-like cooling air nozzle 18 B, and is tiltable as in the cooling air nozzle 18 . The canopy-like member 21 is provided to partition the inner portion of the cooling air nozzle 18 B obtained by cutting a tube main body 18 a into upper and lower portions. A tip end position of the canopy-like member 21 is substantially the same as the tip end position of the flame holder 16 in a tiltable range of the nozzle main body 17 and the cooling air nozzle 18 .
[0053] If the cooling fins 20 are optionally attached to, for example, an upper surface of the canopy-like member 21 , a cooling efficiency can be improved. In the illustrated example, the fins alternately protrude from a lower surface of the canopy-like member 21 and an upper surface of the nozzle main body 17 , but the present invention is not limited to this structure.
[0054] In the thus-structured cooling air nozzle 18 B, the tube main body 18 a is shortened and thus, the nozzle itself can be made lightweight. Further, the canopy-like member 21 can shield radiation heat as well as prevent a clinker from adhering to the nozzle main body 17 , so the nozzle main body 17 is not directly exposed to radiation heat.
[0055] Moreover, if the canopy-like member 21 is detachably attached to the tube main body 18 a by means of bolts or the like, in the case where the canopy-like member 21 needs to be replaced as a result of periodical checkup or the like, only the member can be replaced.
[0056] Further, air flow rates of a secondary air and a cooling air may be determined in accordance with a sectional area ratio instead of using the member that partitions a wind box 19 into the secondary air path 12 and the he cooling air path 13 as in a modified example of FIG. 4 . According to this structure, the wind box structure can be made simple and lightweight.
[0057] Further, if the cooling air nozzle 18 B is detachably attached to the nozzle main body 17 by means of bolts or the like and integrated with the nozzle main body, the cooling air nozzle 18 B and the nozzle main body 17 can be tilted at the same time, and the cooling air nozzle 18 B can be replaced alone.
[0058] As set forth above, the burner structure according to the present invention can adjust an air flow rate and thus efficiently cool the nozzle main body 17 with a small amount of air, and can protect the nozzle main body 17 from a falling clinker or radiation heat.
[0059] The present invention is not limited to the above-described embodiments and might be modified as appropriate without departing from the scope of the present invention. For example, a fuel is not limited to pulverized coal, and petroleum coke, fuel oil, or fuel gas can be used instead. | To provide a burner structure that is capable of efficiently cooling a nozzle main body with a small amount of air, and takes an efficient countermeasure against a falling clinker or radiation heat. The burner structure includes: a pulverized coal-air mixture path provided in a burner central portion and supplying a mixture of a fuel and a primary air; a secondary air path provided around the pulverized coal-air mixture path and supplying a secondary air; a cooling air path provided around or above and below the secondary air path and supplying a cooling air; a nozzle main body attached to furnace-side end portions of the pulverized coal-air mixture path and the secondary air path in a tiltable form and provided with a flame holder at its tip end; and a cooling air nozzle attached to a furnace-side end portion of the cooling air path in a tiltable form. | 5 |
BRIEF SUMMARY OF THE INVENTION
[0001] The present invention is a product, and a method to create a solid interface (or barrier) between soil and the sand of a golf sand bunker.
BACKGROUND OF THE INVENTION
[0002] The present invention is a material and method of forming a liner for the stabilization of soil and forming and underground liner for sand bunkers.
[0003] The present invention is a product and a method to create a solid interface (or barrier) between soil and the sand of a golf sand bunker. This barrier, or liner, exhibits unique advantages over other liners or lining systems. The liner can easily be adapted to the contours and nuances of the cut out bunker. The liner material is somewhat porous, allowing water to percolate through to reduce water accumulation and to keep the sand in place. It retards weed growth thus reduces use of herbicides or hand weeding. The barrier material is not rigid so that a ball strike will not crack the barrier. The liner/barrier is flexible enough to dampen, or absorb, the impact when a golf ball hits the sand making for more realistic play.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a side view of a preferred installation of barrier material and construction of a bunker in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0005] The barrier material. The material that is used to form the barrier is a mixture of a dry adhesive, dry plastic cement, fiberglass fiber, lightweight aggregate, water and for some applications, a hardener. This mixture is applied by hand as a semi-solid and allowed to cure. The mixture may be modified to be used with spray application equipment.
Preparing the soil 2 . The soil 2 is prepared by forming the soil 2 and landscape in the configuration that is desired. It is very important to form a “hinge point” 4 outside and under the top edge 6 of the bunker 8 such that there is approximately a 45 degree angle formed by the grade going outside the bunker 8 and the grade underneath the turf 10 surrounding the opening of the bunker 8 . By trial and error, this 45 degree angle was found to allow the hardened liner 10 to anchor and reinforce the opening of the bunker 8 , reduce any chipping of the bunker 8 by maintenance equipment and to allow turf 12 to grow over the lip of the bunker. Once this is formed, the soil 2 is then physically compacted and then a liquid adhesive polymer is applied to bind the surface of the soil. Application of the barrier material. Following a stabilization of the soil 2 , the barrier material 10 is mixed and then applied by hand being mindful to attain a three quarter inch (½″)-(⅝″) thickness all around the bottom and sides of the bunker. The barrier material is then continued on up over the top of the bunker being careful to maintain the 45 degree angle and for at least 6- 8 inches outside the lip of the bunker. Then the barrier is allowed to cure for at least 24 hours after application. Finish surface. After the barrier is allowed to cure, another application of adhesive is sprayed on the surface and a layer of clean, dry bunker sand is spread over the surface to form the faux appearance. Allow (mandatory) 24 hours of curing and the bunker liner is finished. Sand can now be applied as desired and soil /turf can be prepared on top of the upper lip of the bunker. The bunker 8 , includes a floor 14 where a perforated drain pipe of approximately 4 inches to permit proper drainage. The drain pipe 16 is covered in approximately ⅜″ pea gravel 18 for drainage and stability and cover the beveled key way 20 .
[0000]
TABLE ONE
Specifications for the barrier material
General
Specific
Material
Description
Material
Practical Amount *
Dry Powdered
Polymer based
Soil Tech/Las
2-4
lbs./S.F.
Adhesive
gluing agent
Vegas, NV
Plastic cement
Binding Agent
Paragon,
2-4
lbs./S.F.
for enhanced set
Phoenix AZ.
Fibrillated
Fiberstrand F
PSI Fibers
1-2
oz./S.F.
Fibers
Polypropylene
LaFayettte, GA
microfiber
Aggregate
⅛″Pumice Dust
Hess/Pumice/
4-6
lbs./S.F.
Idaho USA
Water
N/A
N/A
.5-.7
gallons/S.F
* The ranges in the practical amount would reflect with normal conditions using less amount and adverse conditions using higher amounts.
[0010] The formula has undergone various iterations to identify the best and longest lasting composition. It has been found that the adhesive needs to be a non-latex polymer type that is not liquid but powder in nature for best suitability. The plastic cement is necessary as a filler and provides the flexibility of the barrier. The aggregate type has been found to have the best size and bulk density to allow for the most desirable amount of hardness and pliability. The overall mixture allows water to percolate through making the barrier unique.
[0011] In accordance with the present invention, set forth below are some of the types of materials which would be suitable for use in the present invention.
[0012] Soil Tech, 6420 S. Cameron Drive, Suite 207, Las Vegas Nev. sells one type of a formulated soil stabilizer or adhesive suitable for use in accordance with the present invention with the following characteristics:
FSB-1000 DP (Dispersable Powder) Dust Palliative, Soil Stabilizer, Slope & Erosion Control Acrylic Co-Polymer Soil Tech 6420 S. Cameron Dr., Suite 207 Las Vegas, NV 89118 (702)873-2023
Composition/Information on Ingredients
[0017]
[0000]
Component
Percent
CAS NO.
Acrylic Co-Polymer
94.0-96.
Non-hazardous
Calcium Carbonate
1-3%
471-34-1
Water
0.5-3%
7732-18-5
Physical and Chemical Properties
[0018]
[0000]
Physical Form:
Powdered solid
Color & Odor:
White, acrylic like odor
pH:
7.0-10.0 1% Solution
[0019] Euclid Chemical, 19215 Redwood Road, Cleveland, Ohio, sells one type of a PSI Fiberstand F, fibrillated polypropylene micro-fiber suitable for use in the present invention with the following characteristics:
[0020] PSI FIBERSTRAD F is a fibrillated polypropylene micro-fiber to concrete reinforcement that complies with ASTM C 1116, Standard Specification for Fiber Reinforced Concrete and Shotcrete, and is specifically designed to help mitigate the formation of plastic shrinkage cracking in concrete. Typically used at a dosage rate of 1.5 lbs/yd 3 (0.9 kg/m 3 ), PSI FIBERSTRAND F micro-fibers have been shown to greatly reduce plastic shrinkage cracking when compared to plain concrete, PSI FIBERSTRAND F micro-fibers also comply with applicable portions of the International Code Council (ICC) Acceptance Criteria
AC32 for Synthetic Fibers:
[0000]
Controls and mitigates plastic shrinkage cracking
Reduces segregation, plastic settlement and bleedOwater
Provides three-dimensional reinforcement against micro-cracking
Increases surface durability, impact and abrasion resistance
Reduction of in-place cost versus wire mesh for non-structural temperature/shrinkage crack control
Easily added to concrete mixture at any time prior to placement
Typical Engineering Data
[0027]
[0000]
Material
100% virgin fibrillated polypropylene
Specific Gravity
0.91
Typical dosage rate
1.5 lbs/yd (0.9 kg/m 3 )
Available lengths:
¼″ (6 mm), ½″ (13 mm), ¾″ (19 mm),
1½″ (38 mm), 2″ (51 mm) and multi-length
blend (ML)
Melt Point
320° F. (160° C.)
Electrical and thermal
low
Conductivity
Water Absorption
negligible
Acid and Alkali Resistance
excellent
Silicon Dioxide: 76.2%
Chem name: Amorphous Aluminum Silicate
Aluminum Oxide: 13.5%
Hardness (MOHS): 6
Ferric Oxide: 1.1%
pH: 7.2
Ferrous Oxide: 0.1%
Radioactivity: None
Sodium Oxide: 1.6%
Softening Point: 900 degrees C.
Potassium Oxide: 1.8%
Water Soluble substances: 0.15%
Calcium Oxide: 0.8%
Reactivity: Inert
Titanium Oxide: 0.2%
(except in the presence of calcium
hydroxide or hydrofluoric acid)
Magnesium Oxide: 05%
Appearance: White powder
Moisture: <1.0%
GE Brightness: 84
[0028] One type of plastic cement that is suitable for use in the the present is manufactured by Paragon Building Products, Inc., 2895 Hamner Avenue, Norco, Calif. 92860 and has the following characteristics:
PRODUCT NAME: PARAGON PLASTIC CEMENT Masonry Cement (CAS # 65997-15-1)
[0000]
Chemical Family:
FORMULA
CAS#
Calcium Salts:
3CaO•SiO2
12168-85-3
2CaO•SiO2
10034-77-2
3CaO•A12O2
12042-78-3
4CaO••A1O3Fe2O3
12068-35-8
CaSO2•2H2O
13397-24-5
Other salts:
Small amount of MgO, and trace amounts of K2SO4
Na2SO4 may also be present
[0031] One type of pumice aggregate that can be used is that produced by Hess Pumice of Idaho which is amorphous aluminum silicate with a chemical analysis of silicon dioxide 76.2%, aluminum oxide 13.5%, ferric oxide 1.1%, sodium oxide 1.6%, potassium oxide 1.8%, calcium oxide 0.8%, magnesium oxide 0.05%, moisture, less than 1%. | The present invention is a product, and a method to create a solid interface (or barrier) between soil and the sand of a golf sand bunker. | 4 |
FIELD OF THE INVENTION
The invention relates generally to fixed-site radio transceiver stations and, more particularly, to data transfer in fixed-site radio transceiver stations.
BACKGROUND OF THE INVENTION
In conventional fixed-site radio transceiver stations (also referred to as base transceiver stations or base stations) used in wireless communication networks, the radio antenna and an associated amplifier are typically mounted high atop a tower structure, and connected to the remainder of the base transceiver station via a radio frequency (RF) feeder cable. The RF feeder cable is also conventionally used to supply DC power supply current to the tower mounted amplifier (TMA).
FIG. 1 is a block diagram of one example of the above-described conventional base transceiver station, for example a base transceiver station used in a conventional GSM (Global System for Mobile communications) wireless communications network. The example of FIG. 1 shows the tower mounted amplifier 11 of the base station connected to the remainder 13 of the base station by RF feeder cable 15 . The remainder portion 13 includes a TMA power supply 17 for providing DC power supply current for use by the tower mounted amplifier TMA. The remainder portion 13 also includes a so-called “bias Tee” module 19 connected to the TMA power supply 17 and also connected to an RF signalling path 12 which is in turn coupled to a radio transceiver (XCVR) of the base station.
The bias Tee module 19 is a conventional apparatus which combines both the RF signalling from RF signalling path 12 and the DC power supply current from the TMA power supply 17 in the RF feeder cable 15 . The RF feeder cable 15 provides RF signalling and DC power supply current to the tower mounted amplifier TMA. The bias Tee module 19 of the remainder portion 13 also separates RF signalling received via RF feeder cable 15 from the power supply current in the RF feeder cable 15 . The bias Tee module described above is a conventional apparatus well known to workers in the art.
The tower mounted amplifier 11 also includes a bias Tee module 19 for separating the RF signalling from the DC power supply current in the RF feeder cable 15 , and for permitting RF signalling from signal path 14 to be transmitted back to the remainder portion 13 via the RF feeder cable 15 while the cable 15 also carries the DC power supply current. The bias Tee module 19 provides the DC power supply current to the local power supply 16 of the tower mounted amplifier TMA. The local power supply 16 provides the tower mounted amplifier TMA with the necessary DC power supply current.
In conventional base transceiver stations such as illustrated in FIG. 1, the tower mounted amplifier TMA is typically designed so that, should a fault occur in the TMA, it will typically be detectable at the remainder portion 13 by detecting changes in the power supply current drawn by the tower mounted amplifier 11 from the TMA power supply 17 of the remainder portion 13 . Such changes in current are conventionally detected by a data processor 20 which receives a digital input from an A/D converter 21 whose analog input is coupled to the DC power supply current output 24 of the TMA power supply 17 .
The tower mounted amplifier TMA includes an amplifier AMP that is coupled to the RF signalling path 14 and to a tower mounted antenna for appropriately amplifying RF signals that are received (Rx) by the tower mounted antenna. RF signals to be transmitted (Tx) by the antenna are typically filtered and applied to a booster before antenna transmission. Such filter and booster functions can be built into the conventional amplifier unit AMP. The tower mounted amplifier TMA of FIG. 1 has associated therewith TMA parameter data which can represent, for example, information associated with the TMA such as product information, serial numbers, filter frequency information, amplifier gain information, alarm limits, etc. When a fixed-site radio transceiver station such as illustrated in FIG. 1 (or at least the TMA thereof) is newly installed, the TMA parameter data is typically input manually to the remainder portion 13 (e.g., to the data processor 20 ). However, if a new tower mounted amplifier TMA is added, or if the existing TMA is replaced, then the parameter data associated with the added/replacement TMA must disadvantageously be manually input to the remainder portion 13 of the fixed-site transceiver. This is both costly and time-consuming.
It is desirable in view of the foregoing to avoid the delay and expense of manually inputting TMA parameter data to the remainder portion 13 of the base transceiver station whenever a new or replacement tower mounted amplifier TMA is installed.
According to the present invention, a tower mounted amplifier can automatically signal the parameter data of the tower mounted amplifier to the remainder portion of the base transceiver station using a power supply current path coupled between the tower mounted amplifier and the remainder portion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates pertinent portions of a conventional base transceiver station for use in a wireless communication system.
FIG. 2 illustrates pertinent portions of an example base transceiver station according to the present invention.
FIG. 3 illustrates a plurality of nominal power supply current levels used to transmit on the RF feeder cable of FIG. 2 parameter data associated with the tower mounted amplifier of FIG. 2 .
FIG. 4 illustrates how the current levels of FIG. 3 can be used to transmit multiple level coded data on the RF feeder of FIG. 2 .
FIG. 5 is similar to FIG. 2, including a detailed example of the power supply current modulator of FIG. 2 .
FIG. 6 illustrates in flow diagram format exemplary operations which can be performed by the power supply current modulators of FIGS. 2 and 5.
DETAILED DESCRIPTION
FIG. 2 illustrates diagrammatically pertinent portions of an example base transceiver station according to the invention. The base transceiver station of FIG. 2, which could be used in, for example, a GSM network, includes a tower mounted amplifier (TMA) 23 and a remainder portion 25 . The tower mounted amplifier portion 23 of FIG. 2 includes a power supply current modulator 22 coupled between the bias Tee module 19 and the local power supply 16 . The modulator 22 uses the TMA parameter data to modulate the power supply current drawn from the TMA power supply 17 (through RF feeder 15 ) by the tower mounted amplifier portion 23 .
The power supply current drawn from the TMA power supply 17 is monitored by an A/D converter 21 coupled to the TMA power supply output 24 , and the digital output of the A/D converter is input to a data processor 27 coupled to the A/D converter. The data processor 27 interprets the digital data received from the A/D converter to thereby recover the TMA parameter data as modulated by modulator 22 onto the TMA power supply current drawn from the TMA power supply 17 . The A/D converter 21 and data processor 27 thus detect and decode the TMA parameter data as modulated onto the TMA power supply current.
The power supply current modulator 22 of FIG. 2 causes the power supply current drawn from the TMA power supply 17 to vary among a plurality of distinct current levels in response to the TMA parameter data input to the modulator 22 . The various current levels are used to represent the TMA parameter data. In order to ensure that the A/D converter 21 can properly resolve the differences between the various current levels used to represent the TMA parameter data, adjacent ones of current levels seen by the A/D converter 21 should preferably be separated from one another by a known minimum amount. The smallest possible separation between two current levels is dependent on the accuracy specifications of (1) the A/D converter 21 and (2) conventional signal conditioning circuits (not shown) included in the current path 28 coupling the TMA power supply 17 to the A/D converter 21 .
Assume, for example, that the current level seen by the A/D converter can be expected to be within a ±7 mA uncertainty range of the actual current level output by the TMA power supply 17 . Assume also for this example that 8 distinct current levels are to be used to transfer the TMA parameter data. A suitable separation between adjacent current levels can then be calculated by subtracting the lowest of the current levels from the highest of the current levels, and dividing the result by 8. The aforementioned ±7 mA uncertainty range introduces an error of ±14/8 mA (=±1.75 mA) into the aforementioned calculation of the separation between adjacent current levels. Thus, a total uncertainty of ±8.75 mA (±7 mA±1.75 mA) must be accounted for when calculating the current level separation.
Assuming also for this example that the A/D converter has a maximum step size of 3.5 mA/step, the aforementioned ±8.75 mA range requires ±3 steps of the A/D converter. Thus, each current level used in the TMA data transfer should be preferably centered in a current level decision interval which extends at least 3 steps of the A/D converter above and at least 3 steps of the A/D converter below that current level. In this example, one additional step is added between adjacent intervals to ensure separation of the adjacent intervals.
FIG. 3 illustrates the above-described example of current levels for use in transferring the TMA parameter data. As shown in FIG. 3, each current level 31 is centered in an interval which extends three steps above and three steps below the current level, and each interval is separated from each adjacent interval by a one step gap. Accordingly, each current level is separated from the next adjacent current level by seven steps, which corresponds in this example to 24.5 mA (7 steps×3.5 mA/step).
FIG. 4 illustrates an example current waveform representing the power supply current i TMA drawn from (output by) the TMA power supply 17 in response to operation of the power supply current modulator 22 of FIG. 2 . The diagram of FIG. 4 illustrates eight current levels, thus providing eight possible signalling symbols. In the example of FIG. 4, i n represents the nominal TMA power supply current drawn by the tower mounted amplifier portion 23 under normal conventional operating conditions, and the remaining current levels are defined by the aforementioned 24.5 mA separations. In FIG. 4, the highest current level, i n +171.5 mA, represents a start symbol, and the nominal current level i n represents a stop (or idle) symbol. In this example, eight symbol times (designated 0 - 7 ) exist between the start and stop symbols, so a symbol octet including eight separate symbols can be transferred during the time between the start and stop symbols. The minimum possible length of the symbol times is determined by the speed of A/D converter 21 and the limits imposed by the RF feeder cable 15 and path 28 .
Also according to the invention, multiple level coding can be utilized in conjunction with the modulation of TMA parameter data. For example, using the eight current levels of FIG. 4, each current level can represent a three bit symbol as shown in FIG. 4 . Thus, in FIG. 4, the symbol transmitted during symbol time 0 corresponds to 110, the symbol transmitted during symbol time 1 corresponds to 101, the symbol transmitted during symbol time 2 corresponds to 110, the symbol transmitted during symbol time 3 corresponds to 011, the symbol transmitted during symbol time 4 corresponds to 111, the symbol transmitted during symbol time 5 corresponds to 000, the symbol transmitted during symbol 6 corresponds to 001 and the symbol transmitted during symbol time 7 corresponds to 011. Thus, the received pattern of bits in this example will be 1101 0111 0011 1110 0000 1011. Such multiple level coding greatly increases data throughput, and can be easily interpreted by data processor 27 which can be, for example, a digital signal processor, a microprocessor, or another suitable data processing apparatus.
FIG. 5 illustrates diagrammatically an exemplary radio base transceiver station according to the invention. FIG. 5 is similar to FIG. 2, and includes a detailed example of the power supply current modulator 22 of FIG. 2 . The exemplary power supply current modulator of FIG. 5 includes a clock 51 having a frequency that corresponds to the symbol rate of the data transfer illustrated in FIG. 4 . The clock 51 is connected to a clock input of a counter 53 . The counter 53 includes parallel outputs which are connected to address inputs A 0 -A 7 of a memory 55 . The memory 55 can be, for example, a non-volatile memory circuit. The memory 55 has data outputs D 0 -D 2 which are connected to respective data inputs of a D/A converter 58 . The three data outputs D 0 -D 2 correspond to the eight current levels of the FIG. 4 example. The analog output Aout of the D/A converter is connected to a control input 52 of a transistor circuit 59 that can sink desired amounts of current and thereby vary the current drawn from the TMA power supply 17 .
The parameter data for the tower mounted amplifier TMA is stored in the memory 55 , and this stored parameter data is addressed by the counter circuit 53 . In response to the clock circuit 51 , the counter 53 steps through the addresses where the TMA parameter data is stored in the memory 55 . Continuing with reference to the example data transfer of FIG. 4, the three-bit output of memory 55 can be converted by the D/A converter 58 into eight distinct control signals (e.g., control voltages) which cause the transistor circuit 59 to sink eight distinct amounts of current, thus resulting in eight distinct power supply current levels (see FIG. 4) drawn from the TMA power supply 17 and seen by the A/D converter 21 . Although a transistor circuit is shown at 59 as a controllable current sink, other suitable controllable current sinks can be used as well.
The clock circuit 51 causes the counter circuit 53 to count up to the number of addresses needed for the complete message. For each memory location addressed by the parallel outputs of the counter circuit 53 , the associated data bits are output to the D/A converter 58 , which converts the bit pattern to a control signal for controlling the transistor circuit 59 . Note that the stop (or idle) symbol 000 of FIG. 4 will, in this example, cause the transistor circuit 59 to assume a high impedance state so that the normal conventional operating current i n is drawn from TMA power supply 17 . The counter 53 is reset at power on, and is also advantageously reset after the stop symbol is output. The counter is easily programmable to count through a sequence of addresses corresponding to the symbol sequence of FIG. 4, namely from stop symbol to stop symbol. Of course, the counter can be programmed to count through any desired sequence of addresses to transmit any desired number of symbol octets (and associated start and stop symbols) like the one shown in FIG. 4 . The reset count preferably selects the stop symbol so no current is sunk at 59 while the counter is reset. The clock 51 can be started at power on (or at system restart) and halted after the stop symbol is output.
The data processor 27 can process the digital output of the A/D converter 21 in the following exemplary manner. Referring also to FIG. 4, before the start symbol ( 111 ) is detected, the data processor 27 can perform, for example, a five times oversampling of the digital output of the A/D converter 21 . Once a change from the idle symbol to the start symbol is detected, the data processor sets sampling points for the remaining symbols in the data transfer at the middle of each of the successive symbol periods 0 - 7 illustrated in FIG. 4 . The digital output from the A/D converter 21 (in this example a three-bit output) is read by the data processor 27 at each sampling point. When the data processor 27 detects the stop symbol (after symbol period 7 in this example), the five times oversampling can start again. After the data processor 27 has received the stop symbol, the data processor 27 can then assemble the message, for example, in the manner described above with respect to FIG. 4 .
The above-described transfer of TMA parameter data from the tower mounted portion to the remainder portion can be executed, for example, whenever the tower mounted amplifier TMA is powered up or restarted.
It should be noted that the above-described current modulation techniques are also applicable to current in a dedicated power supply line rather than the combined power supply/RF feeder line 15 .
FIG. 6 illustrates exemplary operations performed by the power supply current modulator example of FIG. 5 . After power on or restart, at 61 the counter 53 applies the initial address (e.g., the address of the start symbol for the first symbol octet) to the memory 55 . Thereafter at 63 , the memory 55 outputs the addressed data to the D/A converter 58 . At 65 , the D/A converter converts the digital data to an analog control signal for controlling the transistor circuit 59 . At 67 , the transistor circuit 59 sinks an amount of current corresponding to the control signal received from the D/A converter (and thus also corresponding to the digital data output from memory 55 ). If it is determined at 69 that there is more data to be transmitted, then the output of counter 53 is incremented to the next address at 68 , and the procedure is repeated until it is determined at 69 that all data (including the final idle symbol) has been transmitted.
It will be apparent to workers in the art that the controllable current sink can also be readily controlled in the manner described above using a suitably programmed data processing apparatus to input digital data to the D/A converter 58 .
It can be seen from the foregoing that the invention advantageously permits automatic transfer of TMA parameter data using power supply current modulation, and also enhances the data throughput by using multiple level coding.
Although exemplary embodiments of the present invention have been described above in detail, this does not limit the scope of the invention, which can be practiced in a variety of embodiments. | In a fixed-site radio transceiver station, information about a tower-mounted radio frequency amplifier apparatus can be automatically transferred from the tower-mounted radio frequency amplifier apparatus to another portion of the fixed-site radio transceiver station. The information is transferred by modulating a power supply current that is drawn from the other portion by the tower-mounted radio frequency amplifier apparatus. | 7 |
BACKGROUND TO THE INVENTION
[0001] In regions of high evaporation and seasonal rainfall water loss from large open storages due to evaporation is high and is difficult to control.
[0002] Evaporation control in relatively small areas of a few hectares or less is usually achieved with a cover over the total surface and anchored at the edges. Australian Patent Application No. 198429445 discloses a water evaporation suppression blanket comprising of interconnected buoyant segments cut from tyres cut orthogonal to the axis of the tyre and assembled in parallel or staggered array.
[0003] Australian Patent Application No. 199964460 discloses a modular floating cover to prevent loss of water from large water storages through the natural process of evaporation. Comprising of modular units joined together by straps or ties, manufactured from impermeable polypropylene multi-filament, material welded together to form a sheet with sleeves. The sleeves are filled with polystyrene or polyurethane floatation devices to provide flotation and stiffness to the covers. Australian Patent Application No. 200131305 discloses a floating cover with a floating grid anchored to the perimeter walls of the reservoir, and floating over the liquid level inside the reservoir. A flexible impermeable membrane is affixed to the perimeter walls and is loosely laid over the floating grid.
[0004] International Patent WO 02/086258 discloses a laminated cover for the reduction of the rate of evaporation of a body of water, the cover comprising of at least one layer of material that is relatively heat reflecting, and a one second layer of material that is relatively light absorbing.
[0005] These prior art devices are restricted to coverage of limited areas by their inherent:
Dynamic inflexibility on the water surface The need for a fixing mechanism between the modules and/or affixing to the perimeter of the water storage The need to be anchored and held down during high winds.
[0009] International Patent WO 98/12392 discloses a modular cover for large areas consisting of flat polygonal floating body where the faces of the floating body have partly submerged vertical walls with lateral edges. The device has an arched cover with a hole in the top cover for air exchange. Although the wall depth is large under wave and local high surface wind conditions the covers can be blown off the water surface and overturned.
[0010] There is a need for a modular device, which can be easily laid onto large or small water surface areas that will be stable in high wind and wave conditions and remain stable.
BRIEF DESCRIPTION OF THE INVENTION
[0011] To this end the present invention provides a floating modular cover for a water storage consisting of a plurality of modules in which each module includes
[0012] a) an upper surface
[0013] b) a lower surface
[0014] c) side walls
[0015] d) a chamber defined by the upper surface, lower surface and side walls
[0016] e) flotation means associated with said side walls
[0017] f) openings in said lower surface to allow ingress of water into said chamber
[0018] g) openings in said upper surface to allow air to flow into and out of said chamber depending on the water level within said chamber.
[0019] The provision of a closed chamber ensures that water within the chamber functions as ballast preventing the module from being easily blown around or overturned. The openings in the lower surface are large enough to allow water to quickly flow into the chamber when the module is placed into the water storage but small enough to only allow drainage to occur slowly. This is a key difference between the present invention and the device disclosed in WO 98/12392.
[0020] The shape of the module is chosen to provide a large surface cover and the periphery is polygonal, the number of sides determined by the application to allow packing of the modules on the water surface.
a) Hexagonal shaped periphery will tessellate in a closest pack arrangement and will give a greater than 90% cover over the water body b) Octagonal shaped periphery will tessellate with rectangular spaces between the modules and will give about an 82% cover over the water body c) In all cases the module chord section dimension is preferably 1.2 meters
[0024] Although it is possible to link the modules together it is preferred not to have any interconnection between the modules to make manufacture and installation simple. In use the modules will tend to accumulate in an area dictated by the prevailing winds and the area of coverage will depend on the number of modules used. The shape of the individual modules and the movement between them will conserve water storage by limiting the evaporation of the water without interfering with the aqua culture because sufficient area will be exposed to allow oxygenation of the water. It is possible to use ropes or cables to constrain a group of modules to a particular location.
[0025] In a preferred embodiment the upper and lower surfaces are identical with identical openings for water and air ingress and egress. This makes installation easier as the modules don't have to be laid with a particular surface on top. Ideally the modules can be pushed edgewise to the water to hasten the filling with water ballast.
[0026] A baffle may be positioned between the upper and lower surfaces to create two chambers. The upper and lower surfaces may be fluted to strengthen the body and facilitate fluid flow over the surface. Preferably the ridges and valleys of the fluted surface form a multi-point star pattern on the surface which is effective as an omni directional wind lift spoiler.
[0027] The flotation device may be any suitable arrangement to provide buoyancy for the module sufficient to allow the ballasted module to float at the surface of the water storage.
[0028] In another preferred aspect the modules are designed to allow manufacture on site to avoid the need for transportation from the manufacturing location. Blow moulding or thermoforming is a preferred manufacturing method because blow moulding or thermoforming equipment is able to be moved and set up in temporary facilities on site.
[0029] On site manufacture of the module minimises installation costs.
[0030] In a preferred embodiment the module:
a) is constructed with a standard blow moulding or thermoforming process; b) incorporates a UV stabilizer mixed with the plastic moulding material. The formulation determines the exposed life of the module c) is preferably coloured white to reflect as much light and heat as possible to keep the water cool, and the water vapor pressure as low as possible.
DETAILED DESCRIPTION OF THE INVENTION
[0034] Several embodiments of the invention will be described with reference to the drawings in which:
[0035] FIG. 1 is a perspective view of a first embodiment of the invention;
[0036] FIG. 2 is a top perspective of an exploded view of the embodiment of FIG. 1 ;
[0037] FIG. 3 is a side view and side schematic view of the embodiment in FIG. 1 ;
[0038] FIG. 4 is a top perspective view of a second embodiment of this invention;
[0039] FIG. 5 is a top isometric view of a second embodiment of this invention;
[0040] FIG. 6 is a top perspective of an exploded view of the embodiment of FIG. 5 ;
[0041] FIG. 7 is a side view and side schematic view of the embodiment of FIG. 5 ;
[0042] FIG. 8 is a top plan view of a third embodiment of this invention;
[0043] FIG. 9 is a side schematic view of the embodiment of FIG. 10 ;
[0044] FIG. 10 is a side view of the embodiment of FIG. 10 .
[0045] FIG. 11 is a top perspective of an exploded view of the embodiment of FIG. 10 ;
[0046] FIG. 12 is a section view of the interior of the embodiment of FIG. 10 ;
[0047] FIG. 13 is a top isometric view of the embodiment in FIG. 10 with the flotation fingers covered;
[0048] FIG. 14 is a top exploded view of the embodiment in FIG. 10 with the baffle inserted;
[0049] FIG. 15 is an isometric view of four octagonal modules in closest pack arrangement of the embodiment in FIG. 10 ;
[0050] FIG. 16 is a top isometric view of a fourth hexagonal embodiment of this invention;
[0051] FIG. 17 is a right side view of the embodiment of FIG. 16 ;
[0052] FIG. 18 is a front side section view of the embodiment of FIG. 16 with enlarged floatation pods;
[0053] FIG. 19 is an exploded isometric view of the embodiment of FIG. 16 ;
[0054] FIG. 20 is a top isometric view of a fifth embodiment of the invention;
[0055] FIG. 21 is a side view of the embodiment of FIG. 20 .
[0056] In a first embodiment as shown in FIG. 1 and 2 the module is formed from 3 components clipped together. The module is an octagonal pyramid in shape with two chambers. The top section 11 forms a sealed flotation chamber with the separator 12 . The flotation chamber 18 can be filled with a foam to increase module strength and ensure flotation if pierced. The bottom section 13 has water access holes 14 in its sides and the bottom hole 7 , so that the water ballast chamber formed by separator 12 and lower section 13 can fill with water when the module is placed on the water. Access holes 14 and 17 are large enough to allow water to flow into the chamber and allowing for limited passage of the water keeping it fresh, whilst small enough to restrict the drainage. The pitch of the upper surface is designed to allow rain and debris to fall off. The 3 sections may be clipped together using clips 15 or alternatively they can be welded to form air tight seals.
[0057] In a second embodiment shown in FIGS. 4 to 7 the module has a central ballast chamber with ingress for air and water ballast and a peripheral floatation ring. The upper surface 21 and lower surface 22 are sealed together by the peripheral flange or collar 24 to which the flotation ring 25 is attached. Water access holes 23 are provided in the lower section 22 so that the chamber formed by sections 21 and 22 fills with water and allows for limited passage of the water keeping it fresh, whilst also providing water ballast for the module. The water access holes 23 are large enough to allow water to flow into the chamber but small enough to restrict the drainage. Air holes 26 are provided in the collar 24 to provide venting for water access holes 23 , and to equalize the pressure during wind blasts between the upper and lower chamber. The sections 21 and 22 are formed from Ultra Violet (UV) stable materials that can be blow moulded, thermoformed or injection moulded. The inner octagonal submerged pyramid formed by section 22 when flooded has a restricted drain hole 28 retaining the water as ballast and greater interior volume than the top octagonal pyramid to prevent lifting of the module in high wind areas.
[0058] The outer octagonal torus 25 has an outer pitch of 300 , which inhibits the modules stacking on top of each other during exposure to inclement weather and high wind situations. Both inner octagonal pyramids have an outer pitch designed to allow rain and debris to slide off the module.
[0059] The third embodiment of the invention shown in FIGS. 8 to 15 provides a module with identical top and bottom sections so that either surface can be submerged. The module is blow moulded or thermoformed with surfaces 31 and side edges 32 . To assist in forming a ballast chamber the two surfaces are spaced apart and strengthened by the fingers or buoyancy chambers 33 which can be formed during moulding and later sealed to provide sufficient buoyancy for the modules. The buoyancy chambers 33 are designed to provide the module with horizontal floatation on the water body surface. The side edges 32 can incorporate vent holes 35 for ingress and egress of air and water. The side edges 32 are designed to reduce the wear and tear of the modules from wind and water buffeting by being 90% submerged and therefore being water cushioned. The module surfaces are fluted with ridges 34 and valleys 35 to reduce lift during high wind conditions. The ridges 34 can be linear or curved section depending on the wind conditions. The valleys 35 have an exponential or parabolic curve section. The combination of the ridges and valleys forms a star type pattern on the surface being effective as a omni directional wind lift spoiler.
[0060] Ballast control in extreme weather conditions can be effected by placing a baffle 36 within the module. The baffle has holes through it 37 , which provide limited access to the now top and bottom parts of the module. The baffle further reduces the lift on the module by restricting the horizontal ballast distribution of the module. The modules are usually 1.2 metres and the flotation and shape of the inner chamber enables the ballast to be of the order of 150 kilograms.
[0061] The fourth embodiment of the invention shown in FIGS. 16 to 19 provides a module with identical top and bottom sections so that either surface can be submerged as with the previous third embodiment. The hexagonal shape allows closer packing of the modules on a dam surface than does the octagonal modules. These are particularly useful where water quality and aeration is not as important. The module is specifically designed to be thermoformed on site in a single process using a purposely designed, transportable, double sided thermoforming facility. The polymer sheeting can be single or preferably dual layer. The top layer master-batched with Titanium Oxide to produce a white (and hence light reflective) layer, the bottom layer master-batched with carbon to enhance the UV opacity of the polymer. Both polymer master-batches are also mixed with VU stabilizers to prolong the exposed life of the polymer. The design of this embodiment is similar to the third embodiment except that the fingers or buoyancy chambers 33 have been moved from the interior of the module to the perimeter as pods 40 . The top and bottom pyramidal chambers of this embodiment have more folds (or corrugations), shown as ridges 37 and valleys 38 , to enhance the strength of the module. The gradient of the valleys 43 increases as the valley approaches the apex 42 of the device, specifically designed to reduce lift during high wind conditions. The combination of the ridges and valleys forms a multi-point star type pattern on the surface being effective as an omni directional wind lift spoiler. The perimeter 46 , surrounding the top and bottom pod flotation shell 45 of the module, is heat and compression sealed in the thermoforming process to produce the flotation pod 40 . The apex of the perimeter wall fillet 49 can incorporate vent holes for ingress and egress of air and water. The edges 47 of the top and bottom sides of the module are sealed together in the thermoforming process creating the interior cavity 48 of the module.
[0062] The embodiment of FIGS. 20 and 21 is another hexagonal module adapted to be thermoformed from large sheets of high density polyethylene (HDPE). The two portions of the modules are identical. The sheets may be as thin as 0.5 mm and formed into two identical halves in a two mold unit and then pressed and heat welded together at the periphery. Each side of the module has a flotation pod 52 . The flotation pod ensures that the modules stand proud of the water surface with the lower portion of the module is filled with water ballast. The module surfaces are reinforced by an array of embossed ribs 53 approximately 5 mm square. These ribs 53 radiate from the sides toward the central hub 55 . The two hubs 55 incorporate holes for ingress of water or air. In other respects the modules shown in FIGS. 20 and 21 function similarly to the earlier described embodiments.
[0063] For large and remote water storages the modules of each of the embodiments may be manufactured on site using a transportable blow moulding, and/or thermoforming facility that can be erected in a temporary building. For example the embodiment of FIGS. 20 and 21 may be made by a thermoforming machine having two mould cavities mounted on a low loader that can be transported to the water storage. The moulded modules can then be placed in the water and will fill with ballast to provide cover for the water and reduce evaporation. Once a significant proportion of the water surface is covered the evaporation savings are significant. The modules are made from weather resistant polymeric materials and will have a useful life of at least 10 years.
[0064] From the above it can be seen that the present invention provides a unique solution to water evaporation control. Those skilled in the art will also realize that this invention can take many forms apart from those described without departing from the essential teachings of this invention. | A floating modular cover for a water storage consisting of a plurality of modules in which each module includes a chamber defined by an upper surface and a lower surface there being openings in the upper surface to allow ingress of water into said chamber and openings in the upper surface to allow air to flow into and out of said chamber depending on the water level within said chamber to provide ballast for each module floats. The modules prevent water evaporation from the area covered and the shape and size is selected to ensure that the modules are stable in high wind conditions and don't form stacks. The modules may be made from identical hexagonal or octagonal halves by blow moulding or thermoforming. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to an improved hull design for small watercraft and more particularly to a hull design that improves stability, reduces resistance and which affords better handling.
The hull of a watercraft must serve a plurality of generally inconsistent functions in connection with its dynamic characteristics. That is, the hull should be capable of providing very low resistance to forward travel so as to improve the performance of the vehicle in a straight line without necessitating large powering engines. However, at the same time, the hull design should provide good stability of the watercraft when traveling in a straight line.
Somewhat inconsistent with the straight line performance requirements, the hull should also be capable of permitting the watercraft to be maneuvered sharply and without a large degree of side to side rolling. Furthermore, it is desirable to permit some side to side rolling of the watercraft in order to improve its buoyancy and turning ability, however, the watercraft should be stable and not capable of being easily capsized when making sharp maneuvers.
A particularly popular type of small watercraft is of the type that is designed to handle primarily a single rider and which the rider operates in a swimming suit or wetsuit due to the sporting nature of the watercraft. The very compact nature and small size of this type of watercraft aggravates the problems in hull design as already described.
It is, therefore, a principal object of this invention to provide an improved hull design for a watercraft that will increase stability and handling. It is a further object of the invention to provide a hull design that will offer low resistance when running in a straight ahead direction but also which will have high stability in this mode of operation.
It is a further object of this invention to provide a hull design that permits abrupt maneuvering and good handling without adversely affecting the running in a straight ahead direction.
SUMMARY OF THE INVENTION
A first feature of this invention is adapted to be embodied in a watercraft hull for increasing stability and handling and comprises a generally flat undersurface that extends for a portion of the width on both sides of the longitudinal center line of the hull. A pair of curved sections are each formed on respective transverse outward sides of the flat undersurface for generating a reduced pressure area on opposite sides of the flat underside area for reducing frictional loses and increasing stability.
Another feature of the invention is also adapted to be embodied in a watercraft hull for increasing stability and handling and comprises a generally flat undersurface that extends for a portion of the width of the watercraft on both sides of its longitudinal center line. A pair of generally upwardly sloping surfaces are formed on opposite sides of the flat undersurface and each terminate in generally horizontally extending undersurfaces that are adapted to engage the water upon leaning of the watercraft for adding to its stability and for limiting the amount of leaning permitted.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a small watercraft constructed in accordance with an embodiment of the invention.
FIG. 2 is a side elevational view of the watercraft.
FIG. 3 is an enlarged rear elevational view of the watercraft.
FIG. 4 is a family of cross-sectional views taken along the line 1 through 9 of FIG. 2 and show the cross-sectional configuration of the hull.
FIG. 5 is a rear elevational view, in part similar to FIG. 3, and shows the cooperation of the hull and water when traveling under a planing, high speed condition.
FIG. 6 is a bottom plan view showing the water contact area with the hull under the conditions shown in FIG. 5.
FIG. 7 is a graphical view showing the buoyancy forces exerted on the underside of the watercraft in a front to rear direction under the conditions shown in FIGS. 5 and 6.
FIG. 8 is a rear elevational view, in part similar to FIGS. 3 and 5, showing the configuration and water pressures acting when making a turn.
FIG. 9 is a view, in part similar to FIG. 6 showing the water pressure acting on the underside of the watercraft when in the condition shown in FIG. 8.
FIG. 10 is a graphical view showing the front to rear water pressure existent on the watercraft during the conditions shown in FIGS. 8 and 9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first primarily to FIGS. 1 through 4, a small watercraft constructed in accordance with an embodiment of the invention is identified generally by the reference numeral 21. The small watercraft 21 is comprised of a hull 22 and a deck 23. The hull 22 and deck 23 are affixed to each other in a suitable manner and are formed from a suitable material such as a fiber glass reinforced plastic.
The deck 23 forms a raised seat 24 at the rearward portion of the hull 21 which seat is designed so as to accommodate primarily a single rider, shown in phantom in some of the views and identified generally by the reference numeral 25. The seat 24 is disposed at the rearward end of the watercraft 21 and is bounded by a pair of foot well portions 26 that are defined on opposite sides of the seat at their longitudinal inner portions and by a pair of raised gunnels 27 at their outer portion. It should be noted from FIG. 3 that the foot well portions 26 extend rearwardly and open through a transom 28 formed at the rear of the watercraft. This arrangement permits water to enter the foot wells 26 in the event the vehicle becomes capsized so as to facilitate ease of re-entry.
A steering handlebar assembly 29 is supported by a steering support mechanism 31 that is carried by the deck 23 in a suitable manner. The handlebar mechanism 29 is disposed substantially in line with the fore and aft center of gravity G o (FIGS. 6 and 9) of the watercraft 21.
The watercraft 21 is powered by means of a jet drive unit (not shown) that is disposed in the longitudinal center plane of the watercraft 21 in an area positioned beneath and to the rear of the seat 24. This jet drive unit is driven by an internal combustion engine (not shown) in any known manner, which engine is disposed forwardly of the seat 24 and in general alignment with the steering handle 29 so as to locate the center of gravity of the watercraft, as will be described. The water is discharged from the impeller unit of the jet drive unit back to the body of water in which the watercraft 21 is operating through a pivotally supported discharge nozzle 32. The nozzle 32 is steered, in any suitable manner, by means of the handlebar assembly 29 and this steering mechanism may include flexible cables that interconnect the handlebar 29 with the nozzle 32 in a known manner.
In a general sense, the configuration and layout of the watercraft 21 may be considered to be conventional. However, the important features of the invention have to do with the configuration of the underside of the hull and its relationship to the overall balance of the watercraft 21. It is believed that those skilled in the art are well versed on how to arrange such components and reference may be had to my copending application entitled "Component Layout For Small Watercraft", Ser. No. 935,337, filed Nov. 26, 1986 and assigned to the assignee of this application for a description of how the components may be arranged to achieve the desired location of the center of gravity.
The hull configuration and how it operates to produce the desired results will now be described by primary reference to FIGS. 3 through 10. The undersurface of the hull 22 includes a centrally positioned, relatively shallow longitudinally extending keel 33 that extends from the bow of the boat and which terminates adjacent to the transom 28. As may best be seen in FIGS. 6 and 9, the keel is narrow at the front of the hull 21 and tapers outwardly toward the transom 28. At the rear end of the hull 22, the keel 33 has a width that is about equal to one-third of the total width of the watercraft. It should be noted from FIGS. 6 and 9 that the sides of the rear portion of the keel 33 extends in a generally parallel direction relative to the longitudinal center line of the watercraft.
On opposite sides of the keel 33, the underside of the watercraft is formed with a first pair of arcuate shaped sections 34 that define a concave area in the underside of the hull. These concave portions 34 are designed, as will become apparent, so as to provide a negative pressure or reduced pressure area that will improve stability during straight ahead running. The outer peripheral edges of the concave portions 34 are defined by raised projections 35 which act like chines so as to provide stablity in a forward running mode as will become apparent.
Disposed transversely outwardly of the chines 35, there is provided a second pair of concave areas 36. The second concave areas 36 also terminate in a second pair of generally longitudinally disposed chines 37.
It should be noted from FIGS. 6 and 8 that the chines 35 and 37 extend generally in a longitudinal direction and parallel to the longitudinal center line of the watercraft until a point well forward of the center of gravity G o . Forwardly of this point, the chines 35 and 37 curve inwardly toward the bow of the watercraft.
The hull curves upwardly from the outer periphery of the chines 37 and terminates in generally horizontally extending chines 38 that are positioned a substantial height above the chines 35 and 37.
The configuration of the underside of the hull as thus far described is very effective in providing good stability when running at high speeds in a straight ahead direction while, at the same time, insuring against high fluid resistances. Furthermore, the hull configuration is such that it permits the operator to lean and tilt the boat into a turn while, at the same time, offering good resistance to overturning and stability that will assist in turning.
FIGS. 5 through 7 show the condition when running in a straight ahead direction and at high or planing speeds. It will be noted from FIG. 6 that the water contact area on the bottom of the watercraft is confined primarily to the keel area 33 and the area of the outer pair of chines 37. In addition, the tips of the chimes 35 will just contact the water so as to provide good stability in the straight ahead direction. As may be seen from FIG. 6, the amount of contact area is relatively small and nevertheless there is adequate buoyance. FIG. 7 illustrates the buoyant force curve with respect to the normal center of gravity of the watercraft unloaded (G o ) and also that of the watercraft when a rider is in place, this center of gravity being indicated by the point G 1 . The fact that no water exists in the area of the recesses 36 and 37 causes a reduced pressure area that assists in the holding of the watercraft in a straight ahead position.
If the watercraft operator wishes to execute a turn, he steers the handlebar 29 in the appropriate direction and leans the watercraft into the turn. When making a left turn, this will cause the hull at the left side of the watercraft (in the illustration of FIGS. 8 through 10) to become submerged while the hull at the right hand side will raise. The chines 35 will, however, be maintained submerged as will the entire side of the watercraft to the left of this. As may be seen from FIG. 9, therefore, there is a good buoyant force that will prevent overturning. Also, the horizontally extending surface 38 of the outermost chines will provide very good stability and will reduce the likelihood of overturning when leaning in this manner. However, the fact that the recessed areas 34 and 36 as well as the area 38 are out of the water in normal straight ahead running, assist in the leaning of the watercraft to shift from the position shown in FIGS. 5 through 7 to the position shown in FIGS. 8 through 10.
It should be readily apparent from the foregoing description that the described watercraft configuration provides very good handling, low resistance toward straight ahead running and, furthermore, extremely good maneuverability. Although an embodiment of the invention has been illustrated and described, various changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims. | A hull configuration for a watercraft that improves stability in straight ahead running without significantly increasing the resistance to forward movement. The hull is comprised of a generally flat center section that is surrounded on each longitudinal side by a pair of arcuate sections, the outer peripheries of which are defined by respective chines. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Reference is made to a copending application entitled "Stable Tiltable Display Terminal", Ser. No. 683,578, filed concurrently with the present application by Ralph J. Lake, Jr., et al., and assigned to the same assignee as the present application.
Reference is also made to a copending application entitled "Display Terminal", Ser. No. 683,683, filed concurrently with the present application by Timothy R. Stern, et al., and assigned to the same assignee as the present application.
BACKGROUND OF THE INVENTION
Data display terminals have been in use for many years, and, up to recent times, these terminals have used cathode ray tubes for their displays. Cathode ray tubes are bulky, and there has been a need for a data display terminal which utilizes a flat display panel in place of the cathode ray tube. The present invention provides such a data display terminal.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the display panel assembly used in the terminal of the invention;
FIGS. 2 and 3 together are a perspective view of a portion of the housing for the display panel assembly of FIG. 1;
FIG. 4 is a sectional view of a portion of the apparatus of FIGS. 2 and 3 for controlling the tilt of the display panel of the terminal of the invention with respect to its base;
FIG. 5 is a perpective exploded view of the keyboard assembly of the terminal of the invention;
FIG. 6 is a perspective view of the bottom surface of the keyboard assembly; and
FIG. 7 is a side elevational view of the keyboard assembly shown in an elevated position.
DESCRIPTION OF THE INVENTION
The data display terminal of the invention includes, as its display device, referring to FIG. 1, a flat panel 20 mounted in an assembly which permits it to be supported in the terminal assembly of the invention, to be described. In one suitable panel assembly, the panel, which is generally rectangular in shape, has left and right ends 22 and 24, respectively. A plastic cap 30 is secured to each end of the panel, and four apertured mounting brackets 34 are provided as part of a metal plate 36, to which the panel is secured. The brackets 34 are at the upper and lower edges 26 and 28 of the panel.
The panel 20 with caps 30 is secured to a metal frame 40 by means of screws inserted in the apertures in brackets 34. Metal frame 40 includes a flat central portion having an opening in which the panel is seated. The metal frame includes upper and lower tabs 42 and 44 which are extensions of the upper and lower edges 46 and 48 of the frame and extend along a portion of each of the upper and lower edges. The metal frame 40 also includes left and right end walls 50 and 60 which are bent perpendicularly to the flat central portion.
One or more circuit boards 70 carrying circuitry for driving the panel 20 are positioned behind the panel and are secured to the end caps 30 by means of screws. A magnetic shield plate 72 is positioned between the circuit boards 70.
The terminal includes a housing 100 (FIGS. 2 and 3) for the panel assembly described above and comprising a central panel-housing portion 110 having a left end 112 and a right end 114 and left and right end caps 120 and 130 which are adapted to be inserted into the ends 112 and 114 of portion 110 and to be secured to the portion 110 in a manner to be described. These parts may be of extruded aluminum. The panel-housing portion 110 includes a large-area central portion 136 having an upper edge 138 and a lower edge 140. A wall 144 extends forwardly from the upper edge 138 and leads to a U-shaped tubular upper member 150. Similarly, a wall 156 extends forwardly from the lower edge 140 and leads to a U-shaped tubular lower member 160. The walss 144 and 156 are apertured to provide ventilation, and their outer surfaces carry horizontal ribs 170 which serve both decorative and cooling functions. The tubular member 150 includes two spaced-apart slots 152 and 154, inner slot 154 at its inner edge, and outer slot 152 at its outer edge. Slots 152 and 154 extend along the length of member 150. The lower tubular member similarly includes an inner slot 164 and an outer slot 162 which extend along the length of the lower tubular member.
The two U-shaped members 150, 160 face each other to provide aligned recesses, and slots 152, 162 face each other, and slots 154 and 164 face each other to provide aligned recesses for a purpose to be described.
As noted, the end caps 120 and 130 are adapted to engage the ends of the central portion 110 of the bousing, being shaped to mate with the left and right ends of the portion 110 of the housing and to form a tight mechanical fit therewith. The end caps include inwardly projecting tabs 180 which overlie holes 190 in the central portion 110 so that screws can be inserted to secure the parts together.
In addition, when the panel assembly is coupled to the housing, the upper and lower portions 42 and 44 of the frame are seated in the aligned slots 154 and 164, and screws are inserted in holes 200 in the end walls of the end caps and into holes 210 in the end walls 50 and 60 of the frame to secure the panel assembly and housing together. A filter plate 212 can be inserted in the aligned slots 152 and 162.
An on-off switch 220 is seated in the right hand end of the upper U-shaped member 150, and its operating shaft 222 extends through a hole 224 in the upper end of the end cap 130, and its operation knob 230 is attached to the outer end of the shaft. A keyboard connector socket 240 is inserted in the right hand end of the lower U-shaped member 160, and it projects into an access hole 244 in the lower portion of the end cap 130.
A U-shaped base 250 is provided for supporting the monitor 10, and the panel assembly described above is secured to the base as follows. The U-shaped base includes legs 252 and 254 and a connecting arm 256, and, at the free end of each arm, is a central slot 260 and at least two threaded holes 266.
Each side bracket includes at its lower end (FIGS. 3 and 4) similar features (which carry the same reference numerals) for connecting it and the entire panel assembly to the base 250. These features include a horizontally projecting hollow, open-ended tube 231 in which a helical spring 232 is seated. One end 233 of the spring is seated in slot 234 in the end wall of the tube 231, and the other end 235 of the spring projects through an opening 236 in the wall of the tube 231. A bushing or sleeve 237 is threaded on the tube 231 and encloses the tube, and a bracket 238 is slipped over the tube in a tight mechanical fit. The frictional fit of the bracket 238 with sleeve 237 can be adjusted by opening or closing the bracket by means of a screw inserted in the tab 270 and used to pull the two part of the tab together and narrow space 239. The end 235 of the spring also enters a slot 244 in the bracket 238 and engages the bracket.
The bracket 238 is seated on the end of the leg 252 or 254 of the U-shaped base 250 with a projecting tab 270 on the bracket seated in the slot 260 and a flat portion 280 of the outer surface of the bracket resting on the leg and secured thereto by means of bolts inserted in the apertures 266 and into holes in the bracket.
With all of the parts of the panel assembly connected together, including frame 110, end caps 120 and 130, and with the frame carrying brackets 238 secured to the U-shaped frame 250, the panel assembly can be pivoted to any desired angle with respect to the base 250, and it is held at the desired angle by means of the spring 232.
A keyboard connector 240 is inserted in one of the tubes 231, and the appropriate connections are made therefrom to the keyboard to be used with the panel display. Connections are also made to the panel electronics by cables which enter right hand end cap 130 similar to keyboard connector 240 on left hand end cap 120.
The on-off switch 220 may be omitted, if desired, from terminal 10, with power being applied when the terminal main power cable (not shown) is connected to a power source.
The keyboard assembly 318 for the terminal 10 (FIGS. 5, 6, and 7) is mounted in an assembly similar to that for the display panel including a large-area central frame portion 290 having end caps 300 and 310. In a typical assembly, the keyboard 320 is mounted on a printed circuit board 321 carrying the required keyboard circuitry, and the board is coupled to the frame 290 with its upper and lower margins 322 and 324 in aligned slots 326 and 328 in the frame. The keyboard circuit is coupled to the panel assembly by means of a cable 330 extending out of end cap 300. A frame or fascia 334 may also be provided, if desired.
The keyboard assembly is provided with means for elevating its rear portion on a table for the convenience of the operator. For this purpose, the bottom surface 340 of the frame portion 290 slopes downwardly from front to rear to provide a depression toward the rear of the bottom surface. A wall 344 extends across the rear of the depression, and an elongated plate 348 is positioned in this depression at the rear of the bottom surface and is pivotably coupled to the side walls of the frame portion 290. The plate 348 is thin enough to fit flat in the depression. | A data display terminal comprises a flat display panel assembly pivotably secured to a base by means of a friction sleeve and a torsion spring so that the display panel assembly can be pivoted with respect to said base and can be held at any selected angular position. | 8 |
FIELD OF THE INVENTION
The invention relates to a releasably detachable wheelchair attachment and more particularly to a passenger carrying platform supported by three spaced swivel casters, none of which are connected to any other caster.
KNOWN PRIOR ART
Andes, U.S. Pat. No. 6,443,252 was issued on Sep. 3, 2002. The device of the only prior art patent known to applicant lacks the sophistication of the instant device. It has only two wheels, mounted on an axle, and as such, the wheelchair occupant must take special care in both making left and right turns, and especially when backing up. The backing up experience either with or without a passenger on the platform is akin to backing up a truck or car with a fixed axle trailer attached. Not for the faint of heart.
In addition to Andes, the axle that carries the two wheels is disposed beneath the rear of the platform such that when the platform is occupied, there could arise a warping or deformation of the platform, due to the stress placed on the specific tongue used to attach the trailer-platform
BACKGROUND OF THE INVENTION
Wheelchairs, particularly self-powered wheelchairs, such as those powered by a battery and a motor are widely used by individuals who have limited mobility. People who are disabled or otherwise immobilized due to disease or injury to one or both legs. A: use either a motorized wheelchair or an electric scooter. The invention of this application may be attached to either of said mobility devices. A motorized wheel chair costs more than a scooter, is commanded directionally by a multi-directional joy stick and is powered generally by two motors that operate together as well as separately. A scooter has handlebars interconnected to a pivot-able single front wheel to control left and right movement and is powered.
When a person is walking side by side with a motorized wheelchair operating at full speed, the person walking may have difficulties in keeping up with the speed of the wheelchair, therefore is under a high degree of stress when they have to keep up with the speed of the motorized wheelchair and the distance traveled.
There have been previous inventions of a standing platform to be attached to the back of a powered wheelchair, however, such platforms are only equipped with limited number of wheels (two or less). If the rear wheels are poorly positioned at the rear end of the platform and no wheel in the front of the platform, the weight of the standing person would deform the platform and cause a warping or deformation in the rear of the platform and increased weight on the tongue of the platform that connects to the rear of the wheelchair, eventually disabling the mobility of the standing platform.
It is therefore an object of the present invention to provide a standing platform for a motorized wheelchair that is equipped with at least three 360 degree swivel wheels mounted to the bottom surface of the platform.
DEFINITIONS
The term “PSP” as used herein means personal standing platform.
The term “motorized vehicle” as used herein, pertains to a motorized wheelchair or a two handled battery powered scooter.
The term “towing vehicle” shall be used interchangeably with motorized vehicle.
SUMMARY OF THE INVENTION
There is disclosed a releasably detachable passenger standing platform that attaches behind a motorized wheelchair or scooter onto the mounting means for the stabilizer wheels. These are the little wheels mandated to prevent the wheelchair or scooter from tipping backward on a hill or for some other reason when the load becomes unbalanced. The platform may be tilted up when not in use The platform has 2 trailing swivel casters and one leading centrally disposed swivel caster mounted to the underside of a rearwardly elongated platform sized to accommodate an adult person. The ability to ride short or long distances on the standing platform permits the companion, spouse, care giver or child of the vehicle operator to maintain the pace of the vehicle operator for extended periods of time.
It is a first object therefore to provide a spring loaded passenger platform that attaches semi-permanently to the rear of a motorized wheelchair or scooter.
It is a second object to provide a passenger standing platform that has a trio of 360 degree swivel casters, mounted on the underside of a platform.
It is a third object to provide a passenger standing platform hereinafter (PSP) that while fully attached to the vehicle, is also spring loaded to move from a first horizontal position to a second vertical position by a gentle foot nudge or even by the finger of a teenager.
It is fourth object to provide a PSP that will not buckle under the stress of being towed with a passenger in place, at speeds up 10 mph, by a motorized vehicle.
It is a fifth object to provide a “PSP” for a motorized vehicle that permits the operator of the motor vehicle, to maintain his/her operating speed.
Other objects of the invention will in part be obvious and will in part appear hereinafter.
The invention accordingly comprises the device possessing the features, properties and the relation of components which are exemplified in the following detailed disclosure and the scope of which shall be indicated in the appended claims.
For a fuller understanding of the nature and objects of the invention, reference should be made to the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is rear top perspective view of the device of this invention.
FIG. 2 is a side perspective view of the device of this invention, mounted to a motorized vehicle.
FIG. 3 is a closeup perspective view of the mounting means of this invention to a towing vehicle.
FIG. 4 is a top plan closeup view of the spring loaded components of this device to raise it from a first in use to the second storage position.
FIG. 5 is a bottom elevational view of the passenger standing platform of this invention stored in its upright position.
FIG. 6 is a side elevational view of the passenger standing platform shown in FIG. 5 .
FIG. 7 is a top perspective view of the platform portion of the device prior to the addition of the non-skid surface.
FIG. 8 is a s right side perspective view showing an occupant standing on the passenger standing platform of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Let us first turn to FIG. 1 , where the passenger standing platform, the invention 10 is seen attached to a mobility vehicle 100 , here a motorized wheelchair of a conventional nature. Such chairs are sold by several vendors, the most popular brand of which is Quickee. All elements of the invention will be cast in 2 digit numbers while those of the mobility vehicle will be in the 3 digit series.
The device 10 includes a platform base 11 that is configured like a ping pong paddle in that it has a forward narrower section 11 A and a wider elongated section 11 B connected by a trapezoidal intermediate section 11 C. See FIG. 2 , wherein imaginary lines of demarcation for the intermediate section 11 C are set out by dashed lines 50 and 51 . Rear section 11 B may have square corners, chamfered corners, or tapered corners as shown here and designated 31 R in FIGS. 1 & 2 . While shown with oblique rounded or chamfered rear corners for the rear section 11 B, the corners need not be so configured. Of course a sharp 90 degree rear corner is to be avoided since a person will be entering and exiting the unit at different frequencies as events unfold.
As seen here, the platform base 11 is almost entirely covered with an anti-skid self adhesive mat. The mat 19 is seen to have a main or central section 20 C and a pair of mirror image side sections 20 L, 20 R the latter which are confined to portion 11 B, while the main part of the mat 20 C extends from the elongated section 11 B to the narrower leading section 11 A. See also FIG. 2 and FIG. 4 . Each of the segments 20 R and 20 L are separated from the main segment 20 C, by a non nonstick stripe 20 NN the runs from the oblique edge 31 to the rear of the platform base. This stripe is built into the non-skid attachment as purchased from vendor, 3M Company. While the mat 19 has been described as having 3 segments, in point of fact it is two somewhat mirror image segments cut to shape from rectangular stock that has the non nonstick stripe incorporated therein. The line 37 designates the abutment of the two sections of the mat 19 that appears as 3 segments 20 C, 20 L, and 20 R.
Platform base 11 has a conventional door hinge half 12 transversely attached via 3 bolts 13 disposed in unnumbered throughbores of the forward or leading section 11 A and aligned un-numbered bores found in the hinge half. The other hinge half is attached in like manner by similar bolts 13 through aligned unnumbered bores in the cover plate 15 and the center segment of the double U mount plate 14 , which plate 14 will be described infra. In essence the forward hinge half 12 is sandwiched between the cover plate 18 and segment F of the double U mount plate.
While the mount plate is seen in FIG. 1 , it is seen better in full in FIG. 2 . The mount plate is referred to as a Double U mount plate because the segments form two inverted U shape members on the two ends of the plate. Reference should simultaneously be made to FIGS. 3 and 4 as well.
The mount plate which is an integrated unit of equal depth front to back, commences with an upwardly disposed segment 14 A, connected to a first horizontal segment 14 B that overlies a first anti-tip wheel 102 . A segment of substantially the same extension downward, 14 C commences from 14 B's second end to form a first inverted U. At the lower terminus of 14 C, a second horizontal segment 14 D, extends inwardly toward the middle of the vehicle. At the second terminus of segment 14 D there is a small downward descending segment 14 E, per FIG. 4 , which at its lower terminus connects to center segment 14 F.
Segment 14 G is a mirror image of 14 E, segment 14 H is a mirror of 14 D, and segments 14 I, 14 J and 14 K are mirror images of 14 A, 14 B and 14 C and form the second inverted U overlying the right anti-tip wheel.
A pair of spaced coil springs 16 are each attached at one end thereof to a respective stand off 17 disposed on the oblique edge 31 F of the platform base 11 . The other end of the respective coil spring is disposed in a bore 18 in section 14 F. See FIG. 4 Since the tension pressure of the springs utilized is chosen to be greater than the pressure to keep the hinge open, the platform base stays in the upright non-use position until moved from the generally vertical storage position to the in-use horizontal position by the pressure of one or two fingers of an adult. The mirror image oblique edges 31 define a trapezoidal section 11 c disposed between the wider and longer section 11 B and the narrower and shorter section 11 A.
FIG. 3 is a closeup view of the right side inverted U consisting of segments 14 K, 14 J and 14 J and the adjoining segment 14 H. Bolt 104 is seen extending between segments 14 K and 14 I through unnumbered aligned bores. The bolt 104 is retained by a lock washer 106 and two nuts 105 . The same retention means is also utilized for the opposite inverted U not seen that overlays the left anti-tip wheel 102 of the mobility vehicle.
In FIG. 5 , the underside of the platform base 11 is seen. Here 3 caster assemblies 21 , each of which is not connected to another caster assembly, are seen with one assembly 21 in the leading area and 2 in the trailing part of the platform base. Each caster assembly 21 includes a rectangular flat plate 25 for mounting, to which is rotatably attached conventional housing 26 and wheel 26 W. Each flat plate 25 has a through bore unnumbered in each corner. A set of spaced 4 bolts 27 , are disposed under the mat 19 . All of said bolts pass through a set of bores in platform base 11 , also not seen, and through the corner bores of plate 25 . These 4 bolts are retained by a pair of nuts 28 on each bolt end. Reference is made to FIG. 7 and the discussion infra. Note that in this FIGURE, FIG. 5 the passenger standing platform device is disposed in a vertical position in this figure.
In FIG. 6 , the platform base 11 , is shown in the vertical position of FIG. 5 is seen from the side. The reader's attention is called to the fact that the platform base tilts forwardly about 30 degrees toward the body of the mobility vehicle 100 , due to the fact that the coil springs when in the relaxed position, retain the platform base pitched forwardly for ease of storage and mobility of the vehicle. The springs eliminate the need for any type of locking mechanism to retain the device in the upward non-use position.
In FIG. 7 , In this FIGURE, the platform base 11 is seen disposed horizontally, that is in the in-use position. Here the bolt heads 27 are seen to be recessed flush with the surface of the platform 11 . All 12 bolt heads are seen in the rectangular pattern corresponding to the locale of each caster assembly 21 . The two caster wheels 26 W of the side by side mounted rear caster assemblies 21 are also visible.
The passenger standing platform is elevated approximately 4 inches from ground level, such that a person of any age can easily step on and step off of the device of this invention. In embodiments of the device, the width of section 11 A ranges from 7 to about 9 inches, while the larger section of the platform ranges from about 10 to 13 inches. The overall length from the hinge rearward may vary from 11 to 15 inches. By using high strength aluminum or steel for the platform and heavy duty caster assemblies, the instant device can be constructed to carry persons of up to 400 lbs in weight. Other suitable materials include plastic such as polycarbonate, and resin reinforced glass fibers. The coil springs utilized have about a 7 lb pressure and have 0.5 inch diameter coils. The hinge employed is a variable pressure hinge available from Stanley Tool Works and other vendors. The operating range may be set from 10 to 25 lbs of pressure, and as utilized the pressure is set at 10 lbs. When detached by removing the two bolts 109 that hold the framework to the anti-slip wheels of the mobility vehicle it is seen that the passenger standing platform weighs about 10 pounds, not including the double inverted U mount plate.
It has been found that since the center of gravity of the device of this invention is on the rear two caster assemblies, when occupied, there is little or no effect on the speed achievable by the mobility vehicle. Thus speeds of up to 10 MPH for a Quickee Model SE-646 have been recorded when the occupant on the device weighed over 150 lbs. On the other hand when the platform is occupied, depending upon the vehicle employed, speeds constituting a slow crawl of say 2 mph, the speed of foot traffic at Epcot Center in Florida, or 5 th Ave. In NYC have also been recorded for this same unit.
While removal of the mount plate bolts is the easiest way to remove the entire device, the cover plate over the hinge and the removal of the 4 bolts is also a mode of separation of the device from the mobility vehicle. Both are within the skill of the art.
FIG. 8 is a side perspective view showing a passenger standing on the device of this invention. Since the device has been fully described, suffice it to say that the platform can be lowered from the position shown in FIG. 5 , vertical to the in use horizontal position merely by the use of the tip of one's shoe or by the use of two fingers from a bending position.
It is seen that the device of this invention affords a very safe environment for an occupant, as the user is only about 4 inches off the ground and has plenty of room to place both feet firmly on the platform. The device maximizes weight distribution, provides increased load capacity, and provides greater stability for the user, coupled with increased navigational control by the “driver” of the mobility vehicle, especially when backing up with the device down in the in use position, as well as when riding with no occupant. With the present invention, two individuals can comfortably ride together whether through the Atlanta Hartsfield airport, or any theme park, or just for a stroll in the neighborhood after dinner, without the companion fighting to keep up with the speed of the mobility vehicle driver, or the vehicle driver having to slow down to keep up with the walking companion.
Clearly both parties, the driver and the rider, are benefited by the use of this invention.
While only a motorized wheelchair is featured in the drawings, the device works equally as well with a scooter and is readily mounted thereto by a person possessing minimum skill.
Since certain changes may be made in the above device without departing form the scope of the invention herein involved, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. | A passenger standing platform for attachment to a mobility vehicle that provides improved support for the rider, increased weightload, and easy mountability and storage capability, The unit has a paddle shape platform base with 3 fully rotating caster assemblies attached to its underside in a triangular configuration and a non-skid mat attached to its obverse side. The platform base is hingedly attached to a mount plate that connects to the mobility vehicle, and is retained in a non-use generally vertical position off the ground by a pair of spaced coil springs attached at opposite ends to the mount plate and to the platform base. | 0 |
RELATED APPLICATIONS
[0001] The present application is a continuation application of U.S. patent application Ser. No. 10/783,004, filed Feb. 19, 2004, allowed.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to improved bearing materials comprising PTFE. These bearing materials are suitable for a variety of applications in, for example, the aerospace, industrial, medical and agricultural industries,
[0004] 2. Description of Prior Art
[0005] It is known in the art to utilize self-lubricating bearings and materials to provide reduced friction and reduced wear in a range of load-bearing applications. These bearings are expected to withstand damage during use and installation. Further, the self-lubricating bearings are typically subject during use to a variety of conditions such as heat and pressure, as well as chemical attack from a variety of substances.
[0006] The choice of a bearing material to meet a given need depends on the specific conditions and performance required and tends to be a complex engineering task in view of the many parameters which must be taken into account. A representative list of conditions that are to be taken into account might include, for example, velocity, pressure (including amount of load, direction of load, and speed of impact of load), dynamic friction, static friction, temperature, chemical exposure, lubrication, dimensional stability, geometrical fit, nature of the counter surface, and susceptibility to fluid lubrication erosion (“cavitation”).
[0007] Conventional friction management materials and systems include roller bearings, ball bearings, and plain bearings. In the plain bearing arena, many different forms of plastics bearing materials comprising a plastic matrix having various fillers and/or porous bonding layers are known. Many of them include polytetrafluoroethylene (PTFE), which is widely known for its low coefficient of friction. PTFE also provides the benefit of being stable under a wide range of temperatures and is inert to most chemicals. However, the wear characteristics, excessive creep and the bond strength to substrates of PTFE are poor, so different supporting materials are incorporated with the PTFE in various ways. Some of these supporting materials include metals, which are believed to draw heat away from the system and thus result in improved wear. In addition, some metals, such as lead, are thought to contribute to the lubricity of the system. However, the science of mechanisms in these systems is not fully understood.
[0008] Many products have been made available in this field, and a variety of patents exist, directed to bearing and other friction-reducing materials incorporating polytetrafluoroethylene (PTFE). For example, many bearing materials incorporate PTFE floc, or short fibers, which are incorporated into a resin material and spray coated onto a substrate. U.S. Pat. No. 3,806,216 describes materials which are representative of this type of construction. In another form, PTFE film has been skived from a solid, full-density PTFE block, then laminated to fabric or metal backers and bonded together with various resin systems. U.S. Pat. No. 4,238,137, to Furchak, describes materials which are representative of this type of construction. PTFE fibers formed into woven or non-woven sheets or fabrics, which are then impregnated with resin (e.g., U.S. Pat. No. 4,074,512) and/or laminated to an epoxy or other backing material (e.g., U.S. Pat. No. 3,950,599) have also been used as bearing materials. PTFE floc or particles have been incorporated into a thermoplastic material, then molded and/or machined into bearings. Further, PTFE dispersions, sometimes combined with fillers, have been dried or otherwise bonded on a sintered metal layer/metal substrate or other metal substrate (e.g., U.S. Pat. Nos. 2,689,380; 5,498,654 and 6,548,188 and Japanese Unexamined (Kokai) Patent Application No. 3-121135).
[0009] U.S. Pat. No. 5,792,525 to Fuhr et al., teaches bearing parts formed from one or more layers of a densified expanded PTFE material which can be machined or otherwise formed to the desired shape. Such materials exhibit good resistance to creep under a load; however, the wear limitations of such materials limit their use in many demanding bearing applications.
[0010] As can be seen from the wide range of PTFE-containing materials described, some solution has been developed for virtually every bearing application; however, the market continues to need lower friction, lower wear systems that enable lower power consumption and longer bearing life. In addition, environmental concerns regarding lead have resulted in a search for lead-free materials that perform as well as, or better than, the current lead-containing materials.
[0011] Accordingly, a need has existed in the field of self-lubricated bearing materials and bearing articles for new bearings exhibiting enhanced wear resistance and low friction relative to conventionally available materials.
SUMMARY OF THE INVENTION
[0012] This invention is a unique wear resistant composite bearing material that solves many of the current problems of the self lubricated bearings market. The bearing material comprises monolithic, or continuous, porous polytetrafluoroethylene materials combined with other polymer materials in a unique configuration which has heretofore not been achieved in the art.
[0013] Numerous forms of porous, monolithic PTFE exist and are suitable in bearing materials of this invention. For example, U.S. Pat. No. 5,677,031, to Allan et al., and U.S. Pat. No. 6,019,920, to Clough, are directed to monolithic porous PTFE structures comprising an open network of fused granular PTFE particles that define a tortuous network of voids throughout the structure. Another example of a suitable porous, monolithic PTFE suitable for a bearing material of the present invention is expanded PTFE, characterized by a structure of nodes interconnected by fibrils, and the appearance of this node and fibril structure can vary depending on whether the material is expanded in one direction (e.g., uni-axial) or in multiple directions (e.g., bi-axial, multi-axial, etc.). Other suitable forms of porous, monolithic PTFE materials suitable in the present invention may include monolithic PTFE sheets which are perforated or otherwise modified to create porosity and other reticulated PTFE forms.
[0014] It has been surprisingly discovered that these porous, monolithic PTFE materials, whether in the form of membranes, rods, tubes or other suitable forms, can be imbibed with polymer resins comprising thermosetting resins or thermoplastic resins, such as described in more detail herein, and bearings made from the resulting imbibed structures exhibit improved wear resistance over that which has been achieved in the prior art.
[0015] Polymer resin materials suitable for imbibing into the ePTFE structures can include a wide range of thermosetting resins including, but not limited to, epoxies and their hybrids, phenolics, polyesters, acrylates, polyimides, polyurethanes, cyanate esters, bismaleimide, polybenimidazole, and the like. The preferred thermosetting resins are those which have high thermal stability (e.g., epoxies, polyamide-imide, cyanate esters and phenolic resins, etc.). In addition, many thermoplastic resins including, but not limited to, polyetheretherketone (PEEK), polyetherketone (PEK), polyaryletherketone (PAEK), liquid crystal polymer (LCP), polyimide (PI), polyetherimide (PEI), acetals, acrylics, fluoropolymers, polyamides, polycarbonates, polyolefins, polyphenylene oxides, polyesters, polystyrenes, polysulfones, polyethersulfones, polyphenylene sulfide, polyvinyl chloride, and the like, may also be imbibed into the ePTFE structures to form low friction, wear-resistant composites.
[0016] Depending on the desired application and performance of the resulting composite material, the polymer resin volume percent of solids and volume ratio of solids (PTFE to polymer resin) may vary significantly. Materials with resin volume percents ranging from 40% to 80% have resulted in suitable composites in accordance with the present invention; however, higher volume percents and lower volume percents are also contemplated to be within the scope of suitable composites for the low friction, abrasion-resistant materials of this invention.
[0017] Depending on the particular performance desired, the imbibed ePTFE composite materials may also incorporate one or more fillers to alter or tailor the performance to meet a specific performance requirement. For example, a filler such as graphite or boron nitride may be included to lower the composite coefficient of friction (COF). Further, fillers such as aluminum oxide, titanium dioxide, glass fiber, or carbon may be used to improve wear resistance, even if such fillers might tend to increase the COF.
DESCRIPTION OF THE DRAWINGS
[0018] The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For purposes of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
[0019] FIGS. 1 and 2 are schematic representations of the rotating test specimen and the test fixture, respectively, for performing wear testing on the materials of the invention;
[0020] FIG. 3 is a graph of the load vs. compression for the test fixture shown in FIG. 1 during wear testing.
[0021] FIG. 4 is a cross-sectional perspective photomicrograph at 250× magnification of the porous monolithic PTFE of Example 1 prior to imbibing with the epoxy.
[0022] FIG. 5 is a cross-sectional perspective photomicrograph at 600× magnification of the expanded PTFE membrane of Example 2 prior to imbibing with epoxy FIG. 6 is a cross-sectional perspective photomicrograph at 600× magnification of the expanded PTFE membrane of Example 2 after imbibing and curing the epoxy.
[0023] FIG. 7 is a cross-sectional perspective photomicrograph at 250× magnification of the expanded PTFE membrane of Example 5 prior to imbibing with epoxy.
[0024] FIG. 8 is a cross-sectional perspective photomicrograph at 300× magnification of the expanded PTFE membrane of Example 5 after imbibing and curing the epoxy.
[0025] FIG. 9 is a graph showing the Coefficient of Friction vs. Number of Laps for the bearing material of Example 5.
[0026] FIGS. 10, 11 , 12 and 13 are cross-sectional perspective photomicrographs of the bearing materials of Comparative Examples 1, 2, 3 and 4, respectively.
[0027] FIG. 14 is a graph showing the Coefficient of Friction vs. Number of Laps for the material of Comparative Example 1.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0028] In the current invention, composite bearing materials are made with a coefficient of friction (COF) similar to pure PTFE, but with a significantly lower wear rate. These novel bearing materials are achieved by imbibing wear resistant polymer resin materials within specific porous, monolithic PTFE structures.
[0029] In order to create such a bearing material, it is important to start with a porous, monolithic PTFE, as noted earlier herein. For example, U.S. Pat. No. 5,677,031, to Allan et al., and U.S. Pat. No. 6,019,920, to Clough., are directed to monolithic porous PTFE structures comprising an open network of fused granular PTFE particles that define a tortuous network of voids throughout the structure. Another example of a suitable porous, monolithic PTFE suitable for a bearing material of the present invention is expanded PTFE, characterized by a structure of nodes interconnected by fibrils, and the appearance of this node and fibril structure can vary depending on whether the material is expanded in one direction (e.g., uni-axial) or in multiple directions (e.g., bi-axial, multi-axial, etc.). Other suitable forms of porous monolithic PTFE materials suitable in the present invention may include monolithic PTFE sheets which are perforated or otherwise modified to create porosity and other reticulated PTFE forms.
[0030] As described earlier, polymer materials suitable for imbibing into the PTFE structures of this invention can include a wide range wear-resistant polymer resins. The term “wear-resistant polymer resins,” as used herein, is intended to refer to polymer resins have a modulus greater than the modulus of PTFE (about 0.7 Gpa), more preferably a modulus of at least 1.5 GPa, and most preferably a modulus of at least 2 GPa. Suitable thermosetting resins including, but not limited to, epoxies and their hybrids, phenolics, polyesters, acrylates, polyimides, polyurethanes, cyanate esters, bismaleimide, polybenimidazole, and the like. The preferred thermosetting resins are those which have high thermal stability (e.g., epoxies, polyamide-imide, cyanate esters and phenolic resins, etc.). In addition, many thermoplastic resins including, but not limited to, polyetheretherketone (PEEK), polyetherketone (PEK), polyaryletherketone (PAEK), liquid crystal polymer (LCP), polyimide (PI), polyetherimide (PEI), acetals, acrylics, fluoropolymers, polyamides, polycarbonates, polyolefins, polyphenylene oxides, polyesters, polystyrenes, polysulfones, polyethersulfones, polyphenylene sulfide, polyvinyl chloride, and the like, may also be imbibed into the porous monolithic PTFE structures to form low friction, high wear composites.
[0031] While the thermosetting or thermoplastic polymer resin(s) enhance the wear resistance of the resulting articles, the selection of the polymer resin is also important for the success of the composite for a number of other reasons, and the particular resin selection may vary depending on the requirements of a given application. For a typical industrial bearing application, the imbibed resin also provides the following beneficial features: completely or partially fills the voids in PTFE, provides bonding capability to other substrates, reduces or prevents deformation under load (i.e., creep resistance), and provides dimensional rigidity. We have found in certain preferred embodiments that the material that best balances all of these properties is an epoxy resin comprising a combination of an epoxy, a curing agent and an additive, i.e., curing accelerator. In a particularly preferred embodiment, the epoxy can be any of bisphenol A, bisphenol F, epoxy cresol novolac, epoxy phenol novolac, and many other commercially available epoxy materials. The curing agent can be, but is not limited to, aliphatic amines, aromatic amines, amidoamines, polyamides, amine complexes, dicyandiamide, urea, imidazoles, polyphenols, anhydrides and acids. However, it is important to note that epoxies may not be the material of choice for every application. For example, if an application required extremely high temperature resistance (450° F.), a polyimide would be better suited for a preferred embodiment. Again, depending on the desired end use, the choice of polymer resin or resins will vary.
[0032] In order to incorporate the thermosetting or thermoplastic polymers into the ePTFE structures, the polymers can be put into liquid form by melting or solvating. One preferred method in making these types of composites is to imbibe a solvated polymer into at least a portion of the void space of the PTFE structure. This method allows for easy control of the polymer loading, as well as simple processing to achieve the final result. In such a process, all ingredients in thermosetting or thermoplastic resins are dissolved in solvent(s). Solvent(s) not only dissolve the ingredients but also function as a wetting agent to wet the porous monolithic PTFE material. The PTFE material is imbibed with this blend. There are a variety of processes for imbibing a PTFE structure, such as dip coating, kiss-roll coating, spray coating, brush coating, vacuum coating, and comparable techniques apparent to one of skill in the art. The solvent(s) is removed after imbibing to leave all solid ingredients in the voids of the PTFE material.
[0033] The imbibed ePTFE composite material, sometimes referred to as a “pre-preg,” can then be put into a form for use as a bearing article. This can be done in one preferred embodiment by bonding the “pre-preg” to a backing or substrate material. Such a backing material can be made of metal, a themosetting material or other suitable substrate to which the pre-preg can bond. For example, a steel sheet and an epoxy mold are two representative forms of suitable substrate. In a preferred embodiment comprising bonding to a steel substrate, the pre-preg can be bonded to the substrate by the following steps: a steel plate substrate is cleaned with methyl ethyl ketone (MEK); the epoxy resin/ePTFE “pre-preg” is put on the steel plate and a release film is placed on the pre-preg side opposite the steel plate. A metal sheet is placed on top of the release sheet. The assembly is put on a Carver press unit and subjected to a compressive load between 40 and 1000 psi, at a temperature of 160-200° C. for a thirty minute duration. During this heating and compressing step, the imbibed epoxy resin flows in the ePTFE structure and is distributed in the porosity, cures (i.e. becomes cross-linked) and bonds to the steel, resulting in a substantially pore-free structure bonded to the steel substrate. The result is a bearing article which has a low friction surface, a tenacious bond between the composite material and the substrate and excellent wear resistance. This article may be used as formed, or alternatively, may be cut, stamped, curled, flanged or otherwise formed into a desired geometry.
[0034] In an alternative preferred embodiment for forming a bearing of this invention, rather than bonding to a substrate, the “pre-preg” may be simply cured between release layers in the manner described above, then the resulting article may be used as formed (e.g., in sheet, tube, etc., geometry) or may be further cut (e.g., washers or the like), stamped, curled, flanged, etc., to provide a form suited to a particular bearing application.
[0035] A further alternative preferred embodiment for forming a bearing material of this invention is to first cure the “pre-preg” between release layers as described above, then subsequently laminate a pressure sensitive adhesive to this composite layer, either with or without the further forming techniques noted above, thus providing a “peel and stick” bearing article, that can be applied to any substrate surface at any time.
[0036] A further alternative technique for forming a bearing material of the present invention is by dry blending at least one epoxy resin powder with PTFE prior to processing the PTFE to form a porous monolithic form, or coagulation, of PTFE dispersion with various resin materials. The resultant resin-containing blends can then be made into various articles, to create the desired bearing composite. For example, U.S. Pat. No. 4,096,227, to Gore, gives examples for achieving such a result. The resulting structures can then be cured as described above and incorporated into a form of a bearing material of the present invention.
[0037] The resulting bearing materials of this invention may be used in a variety of industrial, aerospace, medical, agricultural and other applications where the advantageous features of low-friction, or lubriciousness, and wear-resistant load bearing are desirable. Exemplary articles contemplated may include, but clearly are not limited to, bearings, washers, clutches, tensioning devices, wear-resistant surfaces, and the like, in the form of three-dimensional articles, coatings, surfaces, etc.
[0038] Bearing samples in the present invention were prepared according to the procedure described above for bonding to a steel plate, then they were tested for their resistance to wear based upon the wear tests described below.
Test Methods
[0000] Wear Test
[0000] Apparatus:
[0039] A testing device was made substantially in accordance with ASTM D 3702. The apparatus is designed to test the wear rate of self-lubricating materials and utilizes a thrust washer specimen configuration. The test machine is operated with a stationary test sample, and a steel rotating test specimen against the sample, under load. All samples were tested at a load of 26 pounds (130 psi) and a velocity of 540 rpm (150 fpm). In order to apply the correct load and speed, a fixture was designed to fit in a Bridgeport milling machine Model J Head Series II. The fixture was spring loaded so that, when compressed to the appropriate distance, it applied a 26 pound load. The milling machine was able to control the amount of compression and the speed at which the fixture operated. See FIGS. 1 and 2 for schematic drawings of the rotating test specimen and the test fixture, respectively.
[0000] Rotating Test Specimen:
[0040] The rotating test specimen was made of 1018 stainless steel, with a finish of 8-12 μ-inch. A diagram of the specimen is shown below. The specimen was exactly copied from the ASTM D 3702 test and is shown schematically in FIG. 1 .
[0000] Test Fixture:
[0041] The test fixture was designed to hold the rotating test specimen and apply a constant load. A schematic drawing of the fixture is shown in FIG. 2 .
[0042] After the fixture was assembled, it was placed on an INSTRON® Universal Material Test Machine Model No. 5567, (Instron Corporation, Canton, Mass.) to determine the amount of compression required for 26 pounds of load. FIG. 3 is a graph of the load vs. compression for the fixture.
[0000] Test Procedure:
[0043] Each sample was tested in the following manner. First, the fixture was mounted in the milling machine and aligned perpendicularly to the base upon which the sample was mounted. This was done to ensure the rotating test specimen would be level on the test sample. Next, the test sample and rotating specimen were cleaned with isopropyl alcohol to eliminate any oils from the system. The test sample was then mounted to the base of the milling machine. Each time a sample was tested a new rotating specimen was mounted to the fixture. Before the test was started, the milling machine was turned on and set to 540 rpm, using a tachometer. The machine was then stopped and the test sample was brought into contact with the rotating specimen.
[0044] A 0.001 inch thick metal shim was placed on the test sample, then the fixture was lowered until it just engaged the shim. The shim was then removed, and the base of the milling machine was raised to compress the spring the correct amount (0.550 inch). The milling machine was then turned on, and the wear test was started. The test was run for the desired time, as noted in the examples.
[0045] After the test, the sample was removed and examined for the amount of wear that had occurred. An optical interferometer was used to measure the wear “scar”. The sample was measured in four locations, and an average scar depth and width were determined. Wear “scars” were measured using a Zygo New View 5000 Scanning White Light Interferometer (Lambda Photometrics, Hertfordshire, UK). Results were obtained using a 5× objective (2.72 micron laternal resolution) and 0.5× zoom (4.53 micron camera resolution) with an appropriate bipolar (up to 145 microns) or extended (up to 500 microns) scan. Z-axis resolution was better than 1 μm. Stage tilt and pitch were adjusted to make surfaces outside the wear scar parallel to the optics before data collection.
[0046] Scar depths were quantified using histograms. Because images were carefully flattened with respect to the optics, the highest part of the image was the surface outside the groove. Date from this image produced the peak with the largest x-axis value in the histogram. This value was taken as the average position of the sample outside the scar. The scar bottom produced a second peak at lower x-axis in the histogram. The distance between the peaks measured from the scar and the area outside the scar was defined as the scar depth.
[0000] Coefficient of Friction Test
[0047] Coefficient of friction testing was carried out at Micro Photonics Inc., located in Irvine, Calif. The test apparatus used was a pin-on-disk tribometer and the test was run in accordance with ASTM G 99-95a. Results are reported as mean Coefficient of Friction.
[0000] Bubble Point
[0048] Liquids with surface free energies less than that of stretched porous PTFE can be forced out of the structure with the application of a differential pressure. This clearing will occur from the largest passageways first. A passageway is then created through which bulk air flow can take place. The air flow appears as a steady stream of small bubbles through the liquid layer on top of the sample. The pressure at which the first bulk air flow takes place is called the bubble point and is dependent on the surface tension of the test fluid and the size of the largest opening. The bubble point can be used as a relative measure of the structure of a membrane and is often correlated with some other type of performance criteria, such as filtration efficiency.
[0049] The Bubble Point was measured according to the procedures of ASTM F316-86. Ethanol was used as the wetting fluid to fill the pores of the test specimen.
[0050] The Bubble Point is the pressure of air required to displace the ethanol from the largest pores of the test specimen and create the first continuous stream of bubbles detectable by their rise through a layer of isopropyl alcohol covering the porous media. This measurement provides an estimation of maximum pore size.
[0000] Air Flow—Gurley
[0051] The resistance of samples to air flow was measured by a Gurley densometer manufactured by W. & L.E. Gurley & Sons in accordance with the procedure described in ASTM Test Method D726-58. The results are reported in terms of Gurley Number, or Gurley-Seconds, which is the time in seconds for 100 cubic centimeters of air to pass through 1 square inch of a test sample at a pressure drop of 4.88 inches of water.
EXAMPLES
Example 1
[0052] A sample of ZITEX G-108 porous PTFE sheet material was obtained from Saint-Gobain Performance Plastics (Taunton, Mass.), measuring 0.008 inch thick, and having a density of 1.21 g/cc and an ethanol bubble point of 1.0 psi. The microstructure of this un-imbibed material is shown in FIG. 4 .
[0053] The sample was imbibed in the following manner. An epoxy resin composition was formulated with a blend of 56.4% EPON™ SU-3 (Resolution Performance Products), 18.8% EPON™ SU-8 and 24.8% ARADUR® 976-1 (Huntsman Advanced Materials, Basel, Switzerland). The epoxy blend was solvated to a 30% solid solution using MEK as a solvent. The material sample was placed on a 6″ diameter wooden hoop and restrained. The sample was first wetted with 100% MEK solution. The epoxy solution was then applied to the PTFE sample by using a foam brush. The MEK was evaporated and subsequent epoxy solution coatings were applied until the microstructure was filled to a level of 30% by weight (44 volume percent of solids) of epoxy to PTFE. Then the hoop was put into a 65° C. oven for 10-15 minutes to remove the MEK completely. The sample was then in the “pre-preg” form. The “pre-preg” was then removed from the hoop, trimmed and bonded to a carbon steel plate measuring 6 inch by 6 inch by 0.0625 inch thick. The bonding was done as previously described. The sample was then tested for wear resistance, and the results are reported in Table 1.
Example 2
[0054] A sample of GORE-TEX® expanded PTFE membrane was obtained (W. L. Gore and Associates, Inc., Elkton, Md.) having a thickness of 3.7 mils, a density of 0.42 g/cc, a bubble point of 16.9 psi, and Gurley Number of 13 sec. The sample was imbibed with an epoxy resin as described in Example 1. The amount of epoxy imbibed was 30% by weight (44% by volume). The sample was bonded to a 6 inch by 6 inch carbon steel plate as previously described. FIGS. 5 and 6 are cross-sectional SEM photomicrographs of the structure prior to imbibing and after imbibing and curing, respectively.
Example 3
[0055] A sample of the GORE-TEX® expanded PTFE membrane used in Example 2 was obtained (W. L. Gore and Associates, Inc., Elkton, Md.). The sample was imbibed with an epoxy resin as described in Example 1. The amount of epoxy imbibed was 69% by weight (80.3% by volume). The sample was bonded to a 6 inch by 6 inch carbon steel plate as previously described, and subsequently tested for wear resistance. Test results are reported in Table 1.
Example 4
[0056] A filled ePTFE membrane was made by coagulating graphite particulate filler (Type 4437, obtained from Asbury Company) with PTFE fine powder dispersion at a ratio of 25 weight percent graphite to 75 weight percent PTFE. A uniaxially expanded membrane was then made as per the teachings in U.S. Pat. No. 3,953,566, to Gore. The membrane was expanded at a ratio of 4:1, and had a thickness of 0.006 inch and a density of 0.60 g/cc. The sample of this material was then imbibed as in Example 1. The final composition comprised by weight about 50% PTFE, 16.7% graphite and 33.3% epoxy (47.8% by volume epoxy). The sample was then bonded to a 6 inch by 6 inch carbon steel plate as previously described and tested for wear resistance. Results are reported in Table 1.
Example 5
[0057] An ePTFE material sample measuring 8 inches by 8 inches with a thickness of 0.008 inch was obtained (W. L. Gore and Associates, Inc.) having a microstructure as shown in FIG. 7 and the following properties: density 0.95 g/cc, ethanol bubble point=2.64 psi, and tensile strength=4437 psi.
[0058] The sample was imbibed in the following manner. An epoxy resin composition was formulated with a blend of 56.4% EPON™ SU-3 (Resolution Performance Products), 18.8% EPON™ SU-8 and 24.8% ARADUR® 976-1 (Huntsman Advanced Materials, Basel, Switzerland). The epoxy blend was solvated to a 30% solid solution using MEK as a solvent. The material sample was placed on a 6″ diameter wooden hoop and restrained. The sample was first wetted with 100% MEK solution. The epoxy solution was then applied to the ePTFE sample by using a foam brush. The MEK was evaporated and subsequent epoxy solution coatings were applied until the microstructure was filled to a level of 30% by weight (44 volume percent of solids) of epoxy to PTFE. To be specific, the composition of 100 g of the composite would consist of 30 g epoxy and 70 g PTFE. Then the hoop was put into a 65° C. oven for 10-15 minutes to remove the MEK completely. The sample was then in the “pre-preg” form. The “pre-preg” was then removed from the hoop, trimmed and bonded to a carbon steel plate measuring 6 inch by 6 inch by 0.0625 inch thick. The bonding was done as previously described. The sample was then tested for wear resistance, and the results are reported in Table 1. FIG. 8 shows the cross-section of the structure of FIG. 7 (unimbibed) after imbibing and curing.
[0059] Coefficient of friction (COF) of the material of this example was also determined by subjecting a sample to the Coefficient of Friction Test, described above. A sample of the composite material made in this Example was bonded to a 1⅝ inch diameter piece of carbon steel, using the bonding technique previously described herein. The steel sample was ¼″ thick, and had been ground flat with a grinding wheel. The sample was then mounted to the pin-on-disc apparatus and tested at the following conditions:
[0060] Load: 3.5N
[0061] Speed: 105 cm/s
[0062] Radius: 17 mm
[0063] Ambient Temperature: 23 C
[0064] Pin type: Ball
[0065] Ball Diameter: 6 mm
[0066] Ball Material: Steel 440C
[0067] #of Laps: 35,000
[0068] The graph shown in FIG. 9 shows the COF as a function of the number of laps. The mean COF was 0.136
TABLE 1 Wear Resistance of Bearing Examples Volume % 24 hr. Wear Example Weight % epoxy (depth in # Epoxy (solids) microns) 1 30 44 6 3 69 80.3 14 4 33 47.8 13.5 5 30 44 4
Comparative Examples
Comparative Example 1
GARLOCK DU™ Bearing Material
[0069] A 6 inch by 6 inch sample of Garlock DU™ bearing material was obtained from the Glacier Garlock Bearings Company (Heilbronn, Germany). The sample was tested for wear resistance as previously described, and results are reported in Table 2. FIG. 10 is a photomicrograph taken at 100× magnification showing in cross-section the microstructure of the DU™ Bearing Material.
[0070] For comparative evaluation, the DU™ bearing material was also tested for coefficient of friction using the Coefficient of Friction Test, described earlier, with the same test conditions identified in Example 1. The graph shown in FIG. 14 shows the COF as a function of the number of laps. The mean COF was 0.149.
Comparative Example 2
RULON® LR Bearing Material
[0071] A 4 inch by 6 inch sample of RULON® LR bearing material, made by Saint-Gobain Performance Plastics (Taunton, Mass.) was obtained from Tri Star Plastic Corporation (Massachusetts). The sample of RULON® LR bearing material was bonded to a 6 inch by 6 inch by 0.0625 inch thick piece of carbon steel using 3M VHB™ pressure sensitive adhesive (St. Paul, Minn.). The sample was then tested for wear as in the other examples, and results are reported in Table 2. FIG. 11 is a photomicrograph taken at 100× showing in cross-section the microstructure of the RULON® LR Bearing Material.
Comparative Example 3
Skived PTFE
[0072] A 6 inch wide by 6 inch long sample of full density skived PTFE film was obtained from the McMaster Carr catalog (Part number 8569K12, 2 mil thick). The sample was etched on one side and bonded to a 6 inch by 6 inch by 0.0625 inch thick piece of carbon steel using 3M VHB™ pressure sensitive adhesive (Minnesota). This sample was also tested for wear resistance, and the results are reported in Table 2. FIG. 12 is a photomicrograph taken at 100× showing in cross-section the microstructure of the skived PTFE bearing material.
Comparative Example 4
NORGLIDE® PRO1.0 T Bearing Material
[0073] A sample of NORGLIDE® PRO1.0 T bearing material was obtained from St.-Gobain Performance Plastics (Taunton, Mass.). This sample was tested, as received, for wear resistance, since it is already bonded to a metal substrate, and results are reported in Table 2. FIG. 13 is a photomicrograph taken at 50× showing in cross-section the microstructure of the NORGLIDE® PRO1.0 T bearing material.
TABLE 2 Wear Resistance of Comparative Examples Comparative 24 hr. Wear Example Material Part (depth in # Identification # microns) 1 GARLOCK DU 19.3 2 RULON LR 53.5 3 Skived ptfe N/a 376.3 4 NORGLIDE Pro 1.0 T 28.6 | A friction-reducing abrasion resistant bearing material is described. The material comprises a monolithic, porous polytetrafluoroethylene (ePTFE) having dispersed therein a wear-resistant thermosetting or thermoplastic resin material. | 1 |
TECHNICAL FIELD
[0001] The present invention relates to fluid flow systems, and more particularly to a push-fit joint assembly, device and method that facilitates the simple connection, disconnection, repair and re-use of piping and tubing system parts without coining or threaded end caps.
BACKGROUND
[0002] Piping systems exist to facilitate the flow of fluids (e.g., liquid, gas (such as air) or plasma). For example, homes, schools, medical facilities, commercial buildings and other occupied structures generally require integrated piping systems so that water and/or other fluids can be circulated for a variety of uses. Liquids and/or gases such as cold and hot water, breathable air, glycol, compressed air, inert gases, cleaning chemicals, waste water, plant cooling water and paint and coatings are just some examples of the types of fluids and gases that can be deployed through piping systems. Tubing and piping types can include, for example, copper, stainless steel, CPVC (chlorinated polyvinyl chloride) and PEX (cross-linked polyethylene). For purposes of the present disclosure, the term “pipe” or “piping” will be understood to encompass one or more pipes, tubes, piping elements and/or tubing elements.
[0003] Piping connections are necessary to join various pieces of pipe and must be versatile in order to adapt to changes of pipe direction required in particular piping system implementations. For example, fittings and valves may be employed at the ends of open pieces of pipe that enable two pieces of pipe to fit together in a particular configuration. Among fitting types there are elbows, “tees”, couplings adapted for various purposes such as pipe size changes, ends, ball valves, stop valves, and partial angle connectors, for example.
[0004] In the past, pipe elements have been traditionally connected by welding and/or soldering them together using a torch. Soldering pipe fittings can be time-consuming, unsafe, and labor intensive. Soldering also requires employing numerous materials, such as copper pipes and fittings, emery cloths or pipe-cleaning brushes, flux, silver solder, a soldering torch and striker, a tubing cutter and safety glasses, for example. The process for soldering pipes can proceed by first preparing the pipe to be soldered, as the copper surface must be clean in order to form a good joint. The end of the pipe can be cleaned on the outside with emery cloth or a specially made wire brush. The inside of the fitting must be cleaned as well. Next, flux (a type of paste) can be applied to remove oxides and draw molten solder into the joint where the surfaces will be joined. The brush can be used to coat the inside of the fitting and the outside of the pipe with the flux. Next, the two pipes are pushed together firmly into place so that they “bottom out”—i.e., meet flush inside the fitting. The tip of the solder can be bent to the size of the pipe in order to avoid over-soldering. With the pipes and fitting in place, the torch is then ignited with the striker or by an auto-strike mechanism to initiate soldering. After heating for a few moments, if the copper surface is hot enough such that it melts when touched by the end of the solder, the solder can then be applied to the joint seam so that it runs around the joint and bonds the pipe and fitting together.
[0005] In recent years, push-fit technology has been employed with piping systems to reduce the dangers and time involved in soldering joints. Push-fit methods require minimal knowledge of pipe fittings and involve far fewer materials than soldering. For example, one may only need the pipes, quick-connect fittings, a chamfer/de-burring tool and tubing cutter in order to connect pipes using push-fit technology.
[0006] The steps involved in connecting piping systems using push-fit technology can be outlined as follows. First, the pipe is cut to the appropriate length and the end of the pipe is cleaned with the de-burring tool. Then the pipe and fitting are pushed together for connection. The fitting is provided with a fastening ring (also called a collet, grip ring or grab ring) having teeth that grip the pipe as it is inserted. The fastening ring device is employed to provide opposing energy, preventing the device from disconnection while creating a positive seal. Accordingly, no wrenches, clamping, gluing or soldering is involved. Push-fit and/or quick-connect technology for piping systems can be obtained, for example, through Quick Fitting, Inc. of Warwick, R.I., USA, suppliers of the CoPro®, ProBite®, LocJaw™, BlueHawk™ CopperHead® and Push Connect® lines of push fittings and related products. Also, such technology is described, for example, in U.S. Pat. No. 7,862,089, U.S. Pat. No. 7,942,161, U.S. Pat. No. 8,205,915, U.S. Pat. No. 8,210,576, U.S. Pat. No. 8,398,122, U.S. Pat. No. 8,480,134, U.S. Pat. No. 8,844,974 and U.S. Pat. No. 8,844,981, the disclosures of which are incorporated herein by reference in their entireties.
[0007] In past pipe coupling technology, the fastening ring is inserted into the fitting body along with a plastic grip ring support that typically fails under extensive tensile testing. Further, the coupling must then be either coin rolled, glued or receive a threaded cap member to retain the fastening ring inside the fitting body. In addition to the added steps for the manufacture and assembly of the coupling, the strength of the plumbing joint is determined by the retaining cap member. The additional steps and components add significant labor and manufacturing costs to the final product cost and reduce the overall production capability due to the extensive time required for proper assembly.
[0008] In addition to the above, when using a threaded retaining cap method, the process of cutting threads into the fitting body and the retaining cap elevates the cost of machining the fitting components. Further, the threaded end cap method requires mechanical assembly as well as the added cost and application of a thread sealant to the threads. In prior efforts that employ a coined retaining cap method, the process of coining the fitting body as the retaining cap significantly increases the cost of final assembly of the fitting. Additionally, the coining process permanently encapsulates the fastening ring inside the fitting, whereby the fastening ring cannot be removed without complete destruction of the ring and fitting.
[0009] Along with additional assembly steps and increased manufacturing costs, past pipe fittings and connection methods do not allow repair for various reasons. In some cases, this is because they are factory sealed, for example. In other cases, it is because the separation of the fitting from the pipe can damage or induce wear on the parts. For example, some push-to-connect fittings provide permanently fixed demounting rings for removing the fittings. The demounting rings can be depressed axially to lift the fastening ring teeth off of the surface of the inserted pipe, such that the pipe can then be withdrawn. This arrangement, however, can subject the fittings to tampering and shorter life. In addition, while fastening ring devices work effectively as an opposing retaining member, their functionality makes them nearly impossible to dismount, remove or detach for re-use. The fastening rings are thus permanently affixed unless they are cut and removed, which then destroys the fastening ring.
[0010] Whether connected by traditional soldering methods or with push-fit methods, past efforts have been specifically provided for the connection of like materials and lack the ability to connect two unlike materials, such as copper with CPVC, PEX or stainless steel, or any other combination of unlike materials. Past methods further invariably require the replacement of fittings and valves, and do not allow re-use of the fittings or valves in instances where only a small internal component needs to be repaired or replaced. Further, past products and methods do not provide enhanced protective retainers among various packing components such that, in the event of degrading or catastrophic failure of internal parts, such parts would be precluded from separating or moving out of the fitting.
SUMMARY
[0011] The present invention provides, in part, a push fitting assembly package that facilitates the re-use of push fittings without damage to the fitting elements or the pipe. The present invention connects piping using no tools, clamps, solder or glues, while creating a leak-free seal at the connected joining area. Further, the present invention can join both like and unlike piping elements without coining or threading the elements into place. The present invention also provides a protective retainer on various packing components such that, in the event of degrading or catastrophic failure of internal parts, such parts would be precluded from separating. As described, various embodiments of the present invention can withstand up to 3600 pounds of pressure or more, and are thus employable within a heating, ventilation and air-conditioning (HVAC) environment.
[0012] The quick connection pipe joint assembly package provided as part of the present invention employs a release pusher member that, when removed, exposes the clamping, sealing and fastening mechanisms of the fitting. The release pusher member, also called the “release pusher” moves axially and can push the fastening ring of the present invention in order to facilitate the release of a cylindrical object such as a piping element held within the fitting.
[0013] For purposes of the present disclosure, a fitting (also referred to as a body member) can encompass a valve member and other piping elements including, but not limited to: a coupling joint, an elbow joint, a tee joint, a stop end, a ball valve member, tubing and other objects having cylindrical openings. In one embodiment of the present invention, one or more sealing member gasket inserts (e.g., O-ring members) fits within a first sealing ring compartment defined in the interior wall of the fitting. In addition, a fastening ring support compartment is machined into the interior wall to retain at least a portion of the body of the fastening ring. The interior housing elements provide integrated support for the sealing member(s) and fastening ring when opposing force is applied to piping elements that have been inserted into the fitting. In various embodiments, a retaining ring and shield member are employed within a retaining ring support compartment machined into the interior wall of the fitting to provide additional support for the fastening ring and to cooperate with the release pusher to facilitate connection and disconnection of piping elements.
[0014] Various embodiments of the present invention provide a novel push fitting joint packing arrangement comprising a sealing ring member, a fastening ring, a fastening ring support member, a shield member, a retaining ring member and a release pusher member. The shield member provided as part of the present invention can be configured so as to be slidable into the fitting and snapped into place during installation prior to the retaining ring member. The shield member can be provided with flat or substantially flat sides to drop into position at an angle other than perpendicular to the central axis of the fitting. No coining is necessary in order to insert the shield member.
[0015] The release pusher provided as part of the present invention is employed to facilitate the release of tubing, piping and other cylindrical objects inserted into a fitting. The release pusher is manually pushed into the cavity formed by the tube support member within the fitting body and tapered edges of the release pusher generally or nearly abut the installed fastening ring. When it is desired to release an inserted pipe, for example, from the fitting, the release pusher can be forced in the direction of the fastening ring such that its angular surfaces depress the fastening ring teeth off of the surface of the inserted pipe, thereby allowing the pipe to be removed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is an exploded front perspective view of one embodiment of a piping joint assembly package in accordance with the present invention.
[0017] FIG. 2 is a partially exploded front perspective cross-sectional view of the piping joint assembly package of FIG. 1 .
[0018] FIG. 3 is a front view of the piping joint assembly package of FIG. 2 .
[0019] FIG. 4 is a front cross-sectional view of the piping joint assembly package as installed in a pipe fitting in accordance with embodiments of the present invention.
[0020] FIG. 5 is a detailed cross-sectional view of encircled portion 5 - 5 of FIG. 4 .
[0021] FIG. 6 is a cross-sectional view of one embodiment of the fitting of the present invention.
[0022] FIG. 7 is a front view of one embodiment of a shield member of the present invention.
[0023] FIG. 8 is a side view of the shield member taken along line 8 - 8 of FIG. 7 .
[0024] FIG. 9 is a front view of a retaining ring in accordance with embodiments of the present invention.
[0025] FIG. 10 is a right side cross-sectional view of the retaining ring taken along line 10 - 10 of FIG. 9 .
[0026] FIG. 11 is a detailed cross-sectional view of encircled portion 11 - 11 of FIG. 10 .
[0027] FIG. 12 is a front view of a fastening ring support member in accordance with embodiments of the present invention.
[0028] FIG. 13 is a right side cross-sectional view of the retaining ring taken along line 13 - 13 of FIG. 12 .
[0029] FIG. 14 is a detailed cross-sectional view of encircled portion 14 - 14 of FIG. 13 .
[0030] FIG. 15 is a front view of a release pusher member in accordance with embodiments of the present invention.
[0031] FIG. 16 is a right side cross-sectional view of the release pusher member taken along line 16 - 16 of FIG. 15 .
[0032] FIG. 17 is a detailed cross-sectional view of encircled portion 17 - 17 of FIG. 16 .
[0033] FIG. 18 is a detailed view of encircled portion 18 - 18 of FIG. 7 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] In the push-fit piping joint assembly 10 of one embodiment of the present invention as shown in FIGS. 1 and 2 , elements of the joint assembly as shown include: a fitting (i.e., fitting body member) 12 having an inner wall 13 and an outer wall 15 . The inner wall 13 forms a cavity 150 extending along a central axis 11 that extends axially through the fitting. The respective diameters of the inner wall 13 and outer wall 15 as measured from the central axis 11 increase from an axially inner segment 21 of the fitting to the axial mid-segment 23 of the fitting, and from the axial mid-segment 23 of the fitting to the axially outer segment 25 of the fitting.
[0035] As shown in FIG. 6 , the fitting 12 includes a first interior wall portion 191 separated from a second interior wall portion 192 by tube stop 33 . At least the first interior wall portion 191 is formed so as to include a sealing ring compartment 41 , a fastening ring compartment 42 and a retaining ring compartment 43 . In various embodiments of the present invention, the compartments 41 , 42 and 43 , as well as tube stop 33 , are formed as part of the inner surface of the fitting 12 through hydroforming or similar methods. In this way, internal compartments within the fitting 12 are sized so as to receive packing arrangement elements as described herein, and the fitting with compartments and tube stop comprises a monolithic, integrated structure.
[0036] In various embodiments of the present invention, as shown in FIG. 6 , retaining ring compartment 43 comprises a front wall portion 130 , a back wall portion 132 and a first linear segment 133 of the inner wall 13 . The back wall portion 132 can have an interior face 150 , a radially inner wall 44 and an exterior face 45 . In various embodiments, the radially inner wall 44 is not parallel with the axis 11 , but rather extends radially outwardly from an axially inner edge 47 to an axially outer edge 48 . In this way, packing arrangement components to be inserted into the fitting need not be perfectly and/or perpendicularly aligned with the radially inner wall 44 , but rather can meet the back wall portion 132 at different angles while still being manipulable into the fitting opening. The radially inner wall 44 thus facilitates ease of insertion and removal of packing arrangement components without coining
[0037] As further shown in FIG. 6 , fastening ring compartment 42 can comprise a second linear segment 135 extending from the front wall portion 130 of retaining ring compartment 43 to a riser segment 137 of the inner wall 13 , and sealing ring compartment 41 can comprise a third linear segment 139 extending from the riser segment 137 to a sealing ring stop wall 140 of the inner wall 13 . The inner wall 13 of the fitting 12 can also include an axially inner segment 142 extending from the sealing ring stop wall 140 to the tube stop 33 . In various embodiments of the invention, the compartments 41 , 42 and 43 and the elements comprising the compartments can be provided in both the first 191 and the second 192 interior wall portions of the fitting 12 , and can be substantially mirror images of one another. As further shown in FIG. 6 , the axially inner segment 21 of the fitting 12 encompasses the axially inner segment 142 of the inner wall 13 , the axial mid-segment 23 of the fitting 12 encompasses the sealing ring compartment 41 and the fastening ring compartment 42 , and the axially outer segment 25 of the fitting 12 encompasses the retaining ring compartment 43 . In various embodiments, as shown in FIG. 6 , the fitting external wall 15 has an axially internal portion 152 , an axial mid-portion 154 and an axially outer portion 156 . The axially internal portion 152 has a first radial distance from the axis 11 , the axial mid-portion 154 has a second radial distance from the axis 11 , and the axially outer portion 156 has a third radial distance from the axis 11 , wherein the third radial distance is larger than either of the first and second radial distances, and the second radial distance is larger than the first radial distance. In this way, the fitting 12 maintains a profile and structure that permits it to house the elements of the packing arrangement as described herein, while retaining significant strength to withstand up to 3600 pounds of pressure or more.
[0038] In various embodiments, a packing arrangement of the present invention can comprise one or more of: at least one sealing ring member 14 (which can be optionally lubricated), a sealing ring support member 17 , a fastening ring 18 , a fastening ring support member 20 , a shield member 22 , a retaining ring member 24 and a release pusher 26 . In various embodiments, the fastening ring 18 , sealing member 14 , sealing ring support member 17 and release pusher 26 each have an internal diameter that allows for smooth and snug engagement of a piping or tubing element external surface (not shown), whereas the shield member 22 and retaining ring member 24 do not contact any piping or tubing element inserted into or removed from the fitting. Further, the release pusher 24 does not contact fitting inner wall 13 during operation. The fitting 12 is substantially hollow, in the sense that the inner wall 13 defines a pipe receiving opening 30 extending axially therethrough.
[0039] In one embodiment, the fitting 12 can be forged CW617N brass, with full porting and full flow fitting, for example. As shown in FIGS. 2 and 3 , for example, the inner wall 13 of the fitting 12 includes an internal stop 33 extending radially inwardly from the inner wall 13 so as to provide a circumferential resistance to tubes inserted on either side of the fitting. The lubricant for the one or more sealing members 14 can be a food grade lubricant, for example. It will be appreciated that the sealing members can comprise a flat ring or washer-type seal member in addition or as an alternative to a circular member of substantially circular cross-section. The fastening ring 18 can comprise a spring steel formulation, for example, that enables the fastening ring to be malformed during installation, while springing back into its originally manufactured position once installed. The fastening ring is capable of grabbing an inserted pipe's surface via two or more teeth 19 to ensure connections cannot be pulled apart. The fastening ring teeth 19 are angled downward from the substantially cylindrical perimeter or base 70 of the ring, toward the tube stop 33 and away from the retaining ring compartment 43 , such that when the pipe is inserted, the teeth exert a pressure against the pipe to discourage the pipe from slipping or moving back out of the fitting. No wrenches, solder, welding, glue and/or twisting and turning the elements are required to form a connection. Specifically, the combination of the sealing ring 14 , fastening ring 18 , shield member 22 and retaining ring member 24 provide a push-fit piping assembly when inserted into any cylindrical pipe in accordance with various embodiments of the present invention.
[0040] In various embodiments, one or more sealing members 14 is of sufficient size to firmly fit within the sealing ring compartment 41 and against third linear wall 139 of the inner wall 13 of the fitting. Fastening ring 18 includes a base portion 70 and a plurality of bifurcated or square edged teeth 19 extending inwardly from and along the base 70 , wherein the base portion 70 is of sufficient diameter to firmly fit within the fastening ring compartment 42 and against second linear segment 135 of the inner wall 13 when the device is assembled. In various embodiments, sealing ring support member 17 includes an axially inner wall 60 and an axially outer wall 62 , wherein the sealing ring support member 17 is positioned at least partially within the sealing ring compartment 41 and at least partially within the fastening ring support compartment 42 , and further wherein the sealing ring support member axially inner wall 60 is adapted to be in mating contact with the sealing ring 14 . As shown in FIG. 5 , the axially inner wall 60 can be formed with an axially extending rampart base 64 and a rampart wall 65 extending radially outwardly of the rampart base 64 . The rampart base 64 can engage the third linear segment 139 of the inner wall 13 and rampart wall 65 can engage the riser segment 137 of the inner wall 13 to provide stable support for the axial pressures received by the support member 17 during operation. The radially interior edge 63 of the sealing ring support member 17 can engage an inserted pipe during operation, and assists in guiding a pipe over the sealing ring 14 for proper alignment. The radially inner wall 69 of support member 17 is angled so as to permit flexing of the fastening ring teeth 19 to a limited degree as the release pusher moves the teeth 19 axially inwardly during operation to facilitate insertion or removal of a piping element.
[0041] As shown in FIGS. 3 and 5 , the base portion 70 of the fastening ring 18 has a front wall 72 , a rear wall 73 and a radially outer edge 74 . In various embodiments, the base portion 70 is positioned within the fastening ring support compartment 42 such that the outer edge 74 engages the second linear segment 135 , and such that the front wall 72 is in mating contact with the axially outer wall 62 of the sealing ring support member 17 .
[0042] As shown in FIGS. 3, 5 and 12 through 14 , the fastening ring support member 20 can include a first axial wall 80 , a second axial wall 82 and a radially outer wall 83 , wherein the fastening ring support member can be positioned within the fastening ring support compartment such that the radially outer wall 83 engages the second linear segment 135 of the inner wall 13 of the fitting, and such that the first axial wall 80 of the fastening ring support member 20 is in mating contact with the rear wall 73 of the fastening ring 18 . In this way, the fastening ring base 70 is securely maintained between the first axial wall 80 of the fastening ring support member 20 and the axially outer wall 62 of the sealing ring support member 17 . As further shown in FIGS. 12 through 14 , the support member 20 includes a radially inner surface 86 , a beveled back edge 85 extending from the second axial wall 82 to the inner surface 86 , and an angled front edge 87 extending from the first axial wall 80 to the inner surface 86 . The angled front edge 87 provides at least partial support to the back edges 165 of the fastening ring teeth 19 during operation.
[0043] As shown in FIGS. 1 through 8 and 18 , the shield member 22 comprises a body having inner 90 and outer 92 faces, an inner edge surface 93 and an outer edge surface 94 , wherein the inner edge surface 93 is substantially cylindrical, and the outer edge surface 94 is not cylindrical. In various embodiments, the outer edge surface 94 is formed with at least two parallel, diametrically opposed edge segments 95 and further is formed with at least two non-parallel, diametrically opposed edge segments 96 . As shown in FIG. 18 each of the parallel edge segments 95 has a width W 1 , and each of the non-parallel edge segments 96 has a width W 2 , where W 2 is greater than W 1 . In this way, the shield member 22 can slide through the opening 200 created by the back wall portion 132 of the retaining ring compartment 43 before the retaining ring 24 is snapped into place. The parallel edge segments 95 can be aligned with the interior edge 47 defining the fitting opening 200 so as to be insertable without coining Once inserted, the edge segments 96 of the shield member outer edge surface 94 are in mating contact with the first linear segment 133 of the retaining ring compartment 43 , whereas the edge segments 95 are not. Further, a first portion 97 of the outer face 92 of the shield member is in mating contact with the front wall portion 130 of the retaining ring compartment 43 , and a second portion 98 of the shield member outer edge surface 92 is not in mating contact with the retaining ring compartment, but is rather in contact with the second axial wall 82 of the fastening ring support member 20 . In various embodiments, the inner face 90 of the shield member 22 is in mating contact with an axially external wall 102 of the retaining ring member 24 , once the retaining ring member is installed.
[0044] As shown in FIGS. 1 through 5 and 9 through 11 , the retaining ring member 24 has an axially internal wall 101 , an axially external wall 102 , a radially internal wall 104 , and a radially external wall 106 . In various embodiments, the axially external wall 102 extends from an overhang surface 110 to a ledge surface 107 of the radially internal wall 104 . Further, a radially extending mid-wall 112 extends from the overhang surface 110 to a radially outer portion 109 of the radially external wall 106 . A radially extending side wall 114 extends from the ledge surface 107 of the radially internal wall 104 to a platform surface 108 of the radially internal wall 104 . As shown in FIG. 5 , the radially outer portion 109 of the radially external wall 106 acts as guide for the outer surface 126 of the release pusher 26 . Further, the mid-wall 112 acts as a retainer for the annular retaining edge 31 of the release pusher 26 . The edge 31 can slide along the overhang surface 110 of the retaining ring member 24 when the release pusher 26 is pushed axially inwardly to engage the fastening ring teeth 19 . The radially extending side wall 114 engages the back wall portion 132 of the inner wall 13 of the fitting 12 , while the ledge surface 107 is in mating contact with the first linear segment 133 of the inner wall. Further, the axially external wall 102 engages the shield member 22 as described above.
[0045] As shown, for example, in FIGS. 15 through 17 , the release pusher 26 is substantially cylindrical, includes an external tip 29 at the fastening ring engaging end 160 thereof, and further includes an annular retaining edge 31 extending radially outwardly of an outer wall 126 , 128 of the release pusher 26 . In various embodiments, the outer wall portion 128 that extends axially inwardly into the fitting 12 during operation can have an external radius that is smaller than the external radius of the outer wall portion 126 of the pusher, which facilitates the sliding contact between outer wall portion 128 and fastening ring support member 20 , as well as the sliding contact between outer wall portion 126 and retaining ring member 24 during operation. As shown in FIG. 17 , the release pusher retaining edge 31 can include a radial outer ledge 124 , a front wall 127 and a back wall 130 . Shield member 22 can be designed and positioned such that it does not contact outer wall portion 128 of the release pusher 26 during operation, so as to minimize any resisting force on the operation of the release pusher. However, it will be appreciated that in various embodiments, the shield member 22 inner edge 93 can extend to the outer wall 128 of the release pusher 26 . In various embodiments, the release pusher 26 can comprise an injection-molded plastic material or a metal material such as brass, for example. When pressure is applied on the back side 162 of the release pusher 26 , the external tip 29 can engage the inside surface 165 of the fastening ring teeth 19 , and the edge back wall 130 can removeably engage a retaining lip 112 extending radially inwardly from the axially inner wall 110 of retaining ring 24 , as shown in FIG. 5 .
[0046] In various embodiments, the fastening ring 18 can be a split ring member or can be an integral member with no split. A split can facilitate insertion and/or removal, by allowing the diameter of the base 18 to be slightly reduced through pressure so that the fastening ring can be more readily manipulable. In further embodiments, the fastening ring support member can also be split. In various embodiments, the shield member 22 can be provided with teeth on the inner edge 93 thereof to act as a secondary fastening ring. Further, in various embodiments, the sealing ring support member 17 and/or the fastening ring support member 20 can be integrally formed into the inner wall 13 of the fitting, thereby becoming a unitary, monolithic structure with the fitting.
[0047] In operation, the fitting 12 of the present invention is provided and one or more sealing members (e.g., 14 ) are inserted into the sealing ring compartment 41 . Next, in the embodiments with an independent sealing ring support member 17 , this member 17 is inserted so as to extend into the sealing ring compartment adjacent the sealing ring 14 . It will be appreciated that a portion of the sealing ring support member 17 will also lie in the fastening ring compartment 42 , as described above, and shown, for example, in FIGS. 4 and 5 . The fastening ring 18 is then inserted into the fastening ring support compartment 42 , followed by the fastening ring support member 20 . Next, the shield member 22 is inserted without any coining or threaded connection adjacent the fastening ring support member, and the retaining ring 24 is then inserted into the retaining ring compartment so as to abut the shield member 22 as described above. The release pusher 26 is then snapped into engagement with the inner surface 104 of the retaining ring member 24 . When a pipe (not shown) is inserted, it travels through the release pusher 26 into the pipe receiving cavity 200 of the fitting 12 , engaging the fastening ring 18 and the one or more sealing members 14 . The sealing members provide a strong, leak-free seal and the fastening ring prohibits any inclination the pipe may have to slide out of position.
[0048] The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the claims of the application rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. | A push fitting joint packaging arrangement allows the re-use and repair of push-to-connect fittings and valves without damage to the fitting or valve elements or the pipe, and without coining, gluing or threaded engagement of parts. In one embodiment of the present invention, the arrangement comprises a sealing member, a fastening ring, a retaining ring member and a shield member. In various embodiments, the shield member has a substantially cylindrical interior surface, and a non-cylindrical exterior surface. | 5 |
This is a division of application Ser. No. 07/636,353 filed Dec. 31, 1990 now U.S. Pat. No. 5,137,919.
FIELD OF THE INVENTION
The invention relates to compounds with a profound effect on protein kinase C activity and mammalian cell proliferation; and methods of using the same.
BACKGROUND OF THE INVENTION
Sphingosine (SPN) is a long chain unsaturated amino alcohol of the formula C 18 H 37 O 2 N found in cell membranes and in high concentration in nervous tissue. Sphingosine and sphingoid base (a long chain aliphatic base comprising a 1,3-dehydroxy-2-amino group at a terminus and derivatives thereof) have been implicated as inhibitors of protein kinase-C (PK-C) and EGF receptor-associated tyrosine kinase (EGF-RK) (Hannun & Bell, Science, 235, 670, 1987; Hannun, JBC, 261, 12604, 1986; Kreutter et al. , JBC, 262, 1632, 1987).
Protein kinase-C activity is related closely to cell growth and recent studies indicate that increased tumorigenicity is correlated with over expression of PK-C.sub.β1 and PK-C.sub.γ in some experimental tumors (Housey et al., Cell, 52, 343, 1988; Persons et al., Cell, 52, 447, 1988). A mutant PK-C 6 induces highly malignant tumor cells with increased metastatic potential (Megidish Mazurek, Nature, 324, 807, 1989). It would appear that aberrant expression of PK-C may relate to tumor progression.
Recent studies indicate that phospholipids, sphingolipids and metabolic products thereof have an important role in the modulation of transmembrane signaling through PK-C and other membrane-associated kinases, such as EGF receptor-associated tyrosine kinase (Hakomori, JBC, 265, 18713, 1990). For example, PK-C activity is promoted by diacyl glycerol and inhibited by sphingosine (Hannun & Bell, supra; Hannun & Bell, Science, 243, 500, 1989; Merrill & Stevens, Biochim Biophys Acta, 1010, 131, 1989).
Sphingosine did not inhibit PK-C in vitro or at concentrations below 100 μM and did not exhibit a stereospecific effect on PK-C (Igarashi et al., Biochem, 28, 6796, 1989). Many of the studies described above employed sphingosine obtained from a commercial source (for example Sigma Chemical Company) and the preparations contained various impurities including 3-O-methylsphingosine, 5-O-methylphingosine and N-methylsphingosine. The impurities are likely to result from the process of preparation, namely methanolysis of sphingomyelin or cerebroside. Furthermore, in the sphingosine backbone, the D-erythro configuration about the chiral carbons is often converted to the D-threo configuration.
Igarashi et al. (supra) found that the inhibitory effect of sphingosine on PK-C activity is due to: (1) the stereospecific configuration of C1 to C3 (D-erythro configuration required); (2) presence of a long-chain aliphatic group-, and (3) perhaps most essential, a negative charge at the primary amino group at C2. If the amino group was N-acetylated, the PK-C inhibitory activity was abolished since the negative charge of an amino group was eliminated by acetylation. However if the anionic character of the amino groups was enhanced by N-methylation, the stereospecific PK-C inhibitory activity was enhanced.
SUMMARY OF THE INVENTION
One object of the invention is to provide a compound and composition for inhibiting metastatic properties of malignant tumor cells, for controlling cell proliferation and for treating various disorders characterized by abnormal cell proliferation.
Another object of the invention is to provide a compound and composition which inhibits protein kinase-C.
A further object of the invention is to provide a compound and composition for inhibiting platelet aggregation.
A fourth object of the invention is to provide a compound and composition for inhibiting inflammation.
Another object of the invention is to provide a method for making N,N,N-trimethylaphingosine.
A sixth object of the invention is to provide a medicament and method of treating malignancy and inhibiting metastatic properties of malignant tumor cells.
These and other objects have been attained by the development of a method for making N,N,N-trimethylaphingosine and observations in vitro and in vivo of its efficacy in controlling cell proliferation, and inhibiting malignant phenotypes of tumor cells.
It has been found that N,N,N-trimethylsphingosine has a higher inhibitory activity on protein kinase-C and metastatic potential of tumor cells than other sphingosine derivatives; inhibits platelet aggregation and tumor-induced platelet interaction; inhibits inflammatory processes; and is water soluble. A striking depression of tumor cell metastasis by N,N,N-trimethylsphingosine could be due to its inhibitory activity on protein kinase-C or on platelet aggregation or on both.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts the structure of N,N,N-trimethylsphingosine and related compounds.
FIGS. 2A-2C show the effect of sphingosine derivatives on human tumor cell growth. In FIG. 2A the growth of human colonic cancer cell line COLO-205 was monitored. In FIG. 2B the growth of human lung cancer cell line LU-65 was monitored. In FIG. 2C the growth of human gastric cancer cell line MKN-74 was monitored. In each Figure the ordinate represents the percent inhibition of tritiated thymidine incorporation, the solid circles represent sphingosine, the open circles represent N,N-dimethylsphingosine and the triangles represent N,N,N-trimethylsphingosine.
FIG. 3 depicts the comparative effect of various reagents on tumor cell differentiation. MKN-74 cells were exposed to N,N,N-trimethylsphingosine (open squares), N,N-dimethylsphingosine (open circles), 8-chloro-cyclic AMP (open triangles), dibutyryl cyclic AMP (solid triangles), sphingosine (solid circles) and hexamethylenebisacetamide (solid squares).
FIGS. 4A and 4B depict the effect of sphingosine derivatives on protein kinase-C activity in A431 cells. The standard liposome method of Kraft and Anderson (Nature 301, 621, 1983) was used. In FIG. 4A the ordinate shows the amount of 32 P-ATP that was incorporated into myelin basic protein. In FIG. 4B radioactive incorporation into histone III-S is depicted on the ordinate. In both panels SP represents sphingosine, MMS represents N-monomethylsphingosine, DMS represents N,N-dimethylsphingosine and TMS represents N,N,N-trimethylaphingosine.
FIGS. 5A and 5B depict the effect of N,N,N-trimethylsphingosine (open circles), N,N-dimethylsphingosine (solid circles) and sphingosine (open squares) on two melanoma cells lines, BL6, a highly malignant cell line, in FIG. 5A and F1, a cell line of low malignancy, in FIG. 5B. Cell proliferation was evidenced by tritiated thymidine incorporation into DNA.
FIGS. 6A-C depict the effect of N,N,N-trimethylsphingosine on lung metastatic deposits after intravenous injection of BL6 cells into mice. Each graph represents the mean and standard deviation of results obtained in 8 animals. In FIG. 6A the open bars depict the total number of lung colony deposits; the stippled bars depict the number of lung colonies with a diameter of greater than 1 mm; and the solid bars depict the number of lung colonies with a diameter of less than 1 mm. Bars 1-3 depict the number of deposits observed 14 days after injection. Bars 4-6 depict the number of lung colony deposits in animals that received BL6 cells and 1 minute later received 0.2 mg of N,N,N-trimethylsphingosine (TMS). Bars 7-9 depict the number of lung colony deposits in animals that received BL6 cells and 0.2 mg of TMS simultaneously. Bars 10-12 depict the number of deposits in animals that received TMS three hours after administration of BL6.
In FIG. 6B the number of lung colonies was determined 16 days after treatment, the treatment consisting of varying doses and routes of administration. Bar 1: 3×10 4 BL6 cells i.v. Bar 2: 5×10 6 BL6 cells s.c. Bar 3: 3×10 4 BL6 cells i.v. with 0.5 mg TMS i.p. one hour later. Bar 4: 5×10 6 BL6 cells s.c. with 0.5 mg sphingosine i.v. one hour later. Bar 5: 5×10 6 BL6 cells s.c. with three doses of 0.5 mg TMS i.v. 2, 3 and 4 days later.
In FIG. 6C the dose responsiveness of BL6 metastatic potential to TMS is presented. Bar I depicts a control comprising colony numbers in lungs of animals wherein 4×10 4 BL6 cells in PBS were injected i.v. Bar 2 depicts the number of colonies in lungs of animals that received 0.1 mg of TMS in 100 μl PBS, 1 minute after injection of BL6 cells. Bar 3 represents animals treated in the same manner except that the dose of TMS was doubled to 0.2 mg. Bar 4 represents animals that were treated similarly but with 0.5 mg of TMS. Bar 5 represents animals that first were injected with 0.5 mg of TMS in PBS and 1 minute later were injected with 4×10 4 BL6 cells in 100 μl of PBS. Sixteen days after treatment, the mice were sacrificed, lungs opened and the number of colonies in the lungs were counted under a dissecting microscope.
FIGS. 7A and 7B depict the effect of N,N,N-trimethylsphingosine (TMS) on platelet aggregation. A 0.45 ml aliquot of human platelet suspension (3-5×10 5 platelets per μl of Tyrode's buffer) was incubated with sphingosine or TMS for 2 minutes. Then platelet aggregation was induced by the addition of either γ-thrombin (FIG. 7A) or adenosine diphosphate (ADP) (FIG. 7B) in 0.05 ml. The degree of aggregation was determined in an aggregometer and the data analyzed with an integrated computer (Kyoto Daiichi Kagaku Co. Ltd.).
FIG. 8 depicts further the dose response of platelet aggregation by sphingoid. Aggregation of the platelets was induced with 10 nM γ-thrombin.
FIG. 9 depicts the inhibition of T-thrombin-induced phosphorylation of 40 kD protein of human platelets by sphingosine and TMS. Human platelets (3×10 5 /μl) were prelabeled with 32 P-phosphoric acid (0.2 mci/ml) in Tyrode's buffer containing 22 mM trisodium citrate, 1 mg/ml glucose and 3.5 mg/ml bovine serum albumin (pH 6.5) for 75 minutes at 37° C. After centrifugation (600× g, 10 minutes), the platelets were resuspended in Tyrode's buffer (pH 7.2), aliquoted in plastic tubes and preincubated at 37° C. for 5 minutes with various concentrations of sphingosine and its derivatives (added as 50% ethanol solutions with a final ethanol concentration of 0.5%). Platelets then were stimulated with thrombin (10 μM). The reactions were stopped after 30 seconds by the addition of 5 x sample buffer, the samples were boiled and loaded onto 10% SDS-polyacrylamide gels. The proteins were separated electrophotectically. Lane 1-control without stimulation by thrombin; Lane 2-stimulation by 1μ unit/ml of γ-thrombin; Lane 3-stimulated by thrombin but added with 1 μM TMS; Lane 4-stimulated by thrombin but added with 10 μM TMS; Lane 5-stimulated by thrombin but added with 20 μM TMS; Lane 6-stimulated by thrombin but added with 30 μM TMS; Lane 7-stimulated by thrombin but added with 20 μM sphingosine; Lane 8-stimulated by thrombin but added with 20 μM N,N-dimethylsphingosine.
FIG. 10 depicts the effect of sphingosine derivatives on mouse T-cell line CTLL. Each point is the mean of three replicates. In the figure DMS represents N,N-dimethylsphingosine and TMS represents N,N,N-trimethylophingosine.
DETAILED DESCRIPTION OF THE INVENTION
N,N,N-trimethylsphingosine (TMS) is highly water soluble, particularly at physiologic pH. Thus the compound has a distinct advantage over sphingosine, N-monomethylsphingosine and N,N-dimethylsphingosine, which are less water soluble, as a modulator of cell proliferation.
As used herein, sphingosine indicates sphingosine irrespective of D- or, L- or, erythro- or threo- configuration.
Further as used herein, "synthetically prepared" means a product prepared from commercially available reagents and building blocks and assembled into sphingosine and derivatives thereof by chemical reaction in vitro. Otherwise, sphingosines are prepared from sphingolipide which occur naturally.
Because of the multi-fuctionalized nature of the parent molecule, sphingosine, direct quaternization by exhaustive methylation (Sommer et al., J. Org. Chem. 36, 824, 1971) or reductive methylation using aqueous formaldehyde (CH 2 O/NAH 2 PO 3 ) is not always reproducible. Alternatively, N,N,N-trimethylsphingosine can be prepared synthetically from commercially available unsubstituted reagents. For example, it is found that unsubstituted sphingosine (Sigma Chemical Company) can be derivatized to form (4E)-N,N-dimethyl-D-erythro-sphingosine by a known method (Igarashi et al. JBC, 265, 5385, 1990). The N,N-dimethylsphingosine so obtained undergoes quaternization in almost quantitative yield.
Briefly, about a 37% aqueous solution of formaldehyde (which is about 20 eq. ) is added to a solution of D-erythro-sphingenine in acetate buffer (NaOAc-AcOH-H 2 O, pH 4.5). The solution is mixed at room temperature for about 10 minutes and then sodium cyanoborohydride (NaBH 3 -CN) is added three times (at about 3.0, 2.0 and 1.0 eq., respectively). Excess methanol is added sequentially at five minute intervals. The solution is concentrated under a nitrogen stream in an "N-EVAP" (Organomation Assoc., Inc., South Berlin, Mass.) and the compound extracted with chloroform. When the quantity is large (that is more than about 5-10 mg), the solution is recommended to further concentration under reduced pressure in a rotary evaporator. The extract can be purified by high pressure thin layer chromatography using standard procedures. By that technique the compound has an R f of about 0.6 in a buffer comprising CHCl 3 :MEOH:NH 4 OH in a ratio of 8:2:0.2 by volume. N,N-dimethylsphingosine prepared as described above was obtained as a colorless syrup in about 80% yield. The molecule has a formula weight of 329.3281 with a formula of C 20 H 40 HNO 2 as deduced from high resolution mass spectrometry.
Then about 30 milligrams (0.091 m/mol) of (4E)-N,N-dimethyl-D-erythro-sphingosine (DMS) are dissolved in about 1.5 ml of anhydrous chloroform. Freshly distilled iodomethane (a volume of about 170 μl, 2.73 m/mol) is added to the DMS solution and the mixture is stirred in the dark at ambient temperature. (The amount of excess iodomethane is not critical and amounts from 25 to 100% in excess produce satisfactory results.) The reaction generally is complete in a few hours, although for convenience the mixture is allowed to stand overnight. Progress of the reaction can be monitored by thin layer chromatography (TLC) using a buffer comprising ethyl acetate:methanol:ammonium hydroxide in a ratio of 20:10:2. After incubation, the precipitated quaternary ammonium salt is diluted with water and then repeatedly extracted with chloroform (3 ml×4). The organic layer is dried over magnesium sulphate and then concentrated in vacuo.
Practicing the above method, 37 mg (86% yield) of compound was obtained as yellow crystals.
The yellow crystals are dissolved with stirring in an aqueous suspension of preneutralized (pH=7.00) anion exchange resin (chloride form, Dowex 1×2-400, 500 mg) at room temperature for three hours. The mixture is then filtered through a sintered glass funnel and then freeze dried (8 millitorr for two days).
Practicing the above method, 26.5 mg (93% yield) of N,N,N-trimethylsphingosine chloride salt was obtained. The structure of the product was ascertained by proton nuclear magnetic resonance (500 MHz, CDCl 3 ) and found to contain nine hydrogen groups and a trimethyl derivatized amino group. 1 H NMR (D 2 O) δ 0.88 (t, 3, J=6.8 Hz, Me), 1.31 (br s, 22, 11xCH 2 ), 2.08 (q, 2, J=6.8 Hz, 2xH-6), 3.29 (s, 9 N + Me 3 ), 3.38 (br s, 1, H-3), 4.13 (br s, 2, 2xH-1), 5.57 (dd, 1, J=3.1 and 3.4 Hz, H-4), and 5.90 (m, 1, H-5). The predicted molecular formula of the compound is C 21 H 44 NO 2 with an expected molecular weight of 342.3372 and mass spectroscopy revealed a formula weight of 342.3371 (C 21 H 44 NO 2 , Δ-0.0003).
The effect of TMS on cell proliferation was demonstrated in part by exposing various tumor cells to the compound in vitro and in vivo. For comparison purposes those same test cells were also exposed to sphingosine and N,N-dimethylsphingosine. A ready advantage of TMS over the other two compounds is its water solubility. N,N-dimethylsphingosine and sphingosine are soluble in water as chloride salts and at slightly acidic pH. At neutral or physiologic pH, those solutions tend to form opaque suspensions. TMS is soluble under acidic, neutral or basic conditions providing stable, clear solutions.
An in vitro assay relying on tritiated thymidine incorporation was used to ascertain the effect of various compounds on cell proliferation. Briefly, tumor cells were seeded in flat bottom 96 well plates (Corning, N.Y.) at a concentration of 2×10 4 cells per well. The cells were cultured for 2 days in DMEM containing various concentrations of sphingoid which was added as a PBS solution. The medium was then supplemented with tritiated thymidine at a concentration of 0.5 μCi per well. Following a six hour incubation the cells were collected using the PHD Cell Harvester (Cambridge Technology, Cambridge, Mass.) and amounts of incorporated radioactivity were determined after adding a suitable cell lysing agent and scintillation cocktail, such as ScintiVerse BD (Fisher Scientific, Fairlawn, Calif.) which performs both functions. In the figures, the results are presented as the percent of cell growth inhibition relative to control cultures that were not exposed to a test substance.
Three cancer cell lines were examined, COLO-205, a human colon cancer line (ATCC No. CCL 222); Lu-65, a lung cancer cell line (T. Yamada et al., Jpn. J. Cancer Res., 76, 967-976 (1985); and MKN-74, a gastric cancer cell line (Motoyama et al., Acta Med. Biol., 27, 49-63 (1979). As depicted in FIG. 2, in each case TMS was superior to sphingosine in the ability to inhibit tumor cell growth. TMS showed an advantage over DMS although not of the same magnitude. Nevertheless because of the increased efficacy of TMS over DMS, lower amounts were required to effect a specified level of inhibition.
The enhanced inhibitory activity of TMS is validated in the data summarized in FIG. 3. MKN-74 cells were exposed to cAMP and derivatives thereof and to HMBA, which are known to inhibit tumor cell growth by differentiation induction. Clearly, TMS was the most effective inhibitor of tumor cell growth.
In another in vitro assay, the influence of various compounds on PK-C activity was monitored. Certain tumor cells present high levels of PK-C activity. The human epidermoid carcinoma cell line A-431 (ATCC No. CRL 1555) was used in a bioassay for PK-C activity as described in Igarashi et al. (supra). Briefly, phosphatidylserine (5 μg/tube) and 1,2-diolein (0.05 μg/tube), with or without an appropriate quantity of a sphingosine derivative sample, were added in an organic solvent, ethanol or ehtanol/chloroform, to a 1.5 ml tube (Sarstedt) and the mixture was evaporated under a N 2 stream. The lipid mixture was sonicated in about 30 μl of 20 mM Tris-HCl (pH 7.5) for 30 minutes. The resulting liposomes were supplemented with a buffer mixture comprising 25 mM Tris-HCl (pH 7.5), 10 mM MgCl 2 , 400 μM EDTA, 50 μM EGTA, 500 μM CaCl 2 , 200 μg/ml histone III-S or myelin basic protein and 20 μM δ[ 32 P]-ATP (2×10 cpm) to a final volume of about 90 μl. The reaction was initiated by adding about 10 μl of PK-C, which was prepared from A431 cells as described in Igarashi et al. (supra) or from mouse brain as described in Kikkawa et al. (Biochem Biophys Res. Comm., 135, 636, 1986) and contained about 1-2 μg protein, and the mixture was incubated f or ten minutes at 30° C. The reaction was terminated by the addition of 1 ml of a 1 mM ATP solution at pH 7.5 containing 25% TCA and 1% BSA. The precipitate was collected by centrifugation, washed twice with 1 ml of 25% TCA, then dissolved in 1 ml of 1M NAOH containing 0.1% deoxycholate with slight heating (80° C. for ten minutes) and counted in a scintillation counter. Reaction mixtures without phosphatidylserine, 1,2-diolein or Ca 2+ were used as controls.
The bioassay used two different substrates, histone III-S and myelin basic protein. Data from a series of experiments are summarized in FIG. 4. Regardless of the substrate, TMS was superior to the other compounds in the ability to inhibit PK-C.
Although the data show a superior PK-C inhibitory activity of TMS over the remaining tested compounds, there are other advantages to TMS. Certain cancer cells show a higher metastatic potential and invasive capability than others. For example the BL6 and F10 melanoma cell lines are highly metastatic and invasive. On the other hand, the F1 variant is much less metastatic and invasive (I. R. Hart et al., Amer. J. Pathol, 97, 587-592 (1979); G. Poote et al., Cancer Res. 42, 2770-2778 (1982); F1 and F10 clones from ATCC CRL 6323, and CRL 6475, respectively). BL6 and F1 cells were tested in vitro as described above. As shown in FIG. 5 TMS was more effective than DMS and sphingosine at inhibiting cell growth. Also BL6 cells were more sensitive to TMS treatment as evidenced by the leftward shift of the TMS curve to lower concentrations.
The effectiveness of TMS in vivo is summarized in the graphs comprising FIG. 6. BL6 cells were injected into mice and metastatic deposits in the lung were assessed after various treatments including route and timing of administration. TMS is effective in suppressing lung colonization and tumor development irrespective of route or timing although early treatment is preferred and repeated treatment is more effective. As revealed in the data summarized in panels B and C, there is a distinct dose responsiveness of lung tumor colonization to TMS.
Another aspect of TMS is the profound effect it has on platelet aggregation. As presented in the data summarized in FIGS. 7 and 8, TMS inhibited platelet aggregation in a dose-responsive fashion.
Upon thrombin stimulation, a 40 kD platelet protein is phosphorylated. As noted in FIG. 9, TMS exposure inhibits phosphorylation of the 40 kD platelet protein. While not wanting to be bound by their statement, the inventors believe that absence of phosphorylated 40 kD protein prevents platelet aggregation.
The utility of TMS is not limited to the suppression of malignant cell growth. Inflammation is characterized in part by a proliferation of lymphoid and myeloid cells. Generally the proliferation serves a beneficial purpose, such as sequestration of foreign antigen or enhancement of restorative capabilities following an insult, but at times can occur abnormally, for example as a result of an autoimmune dysfunction. Thus TMS has utility in controlling cell proliferation of apparently normal cells. Mouse CTLL-2 cells (ATCC No. TIB 214), a T lymphocyte cell line, were plated at 1.5×10 4 cells per well and exposed to test substances. Cell proliferation was monitored by thymidine incorporation. The data of several experiments are summarized in FIG. 10. TMS was significantly more effective in suppressing CTLL-2 cell growth.
Accordingly, the present invention provides a method for inhibiting growth of human and animal cells comprising the step of exposing said human or animal cells to a cell growth inhibiting amount of N,N,N-trimethylsphingosine or pharmaceutically acceptable salts thereof.
The present invention further provides a medicaments and treatments for inhibiting growth in human and animal cells and aggregation of human and animal platelets comprising:
(1) a therapeutically effective amount of N,N,N-trimethylsphingosine or pharmaceutically acceptable salts thereof; and
(2) a pharmaceutically acceptable carrier, diluent or excipient.
The medicaments and methods are applicable both for in vitro and in vivo applications. Specific uses include treatment of malignancies, benign tumorous growths, inflammation, other manifestations of immune system dysfunction and when the immune system inappropriately or excessively responds to a stimulus.
The medicament comprises an effective amount of TMS and a pharmaceutically acceptable carrier, diluent or excipient. The effective amount of TMS can be determined using art-recognized methods, such as by establishing dose-response curves in suitable animal models, such as described herein or in non-human primates, and extrapolating to human; extrapolating from suitable in vitro data, for example as described herein; or by determining effectiveness in clinical trials.
Suitable doses of medicaments of the instant invention depend upon the particular medical application, such as the severity of the disease, the weight of the individual, age of the individual half-life in circulation etc., and can be determined readily by the skilled artisan. The number of doses, daily dosage and course of treatment may vary from individual to individual.
TMS can be administered in a variety of ways such as orally, parenterally and topically. Suitable pharmaceutically acceptable carriers, diluents, or excipients for the medicaments of the instant invention depend upon the particular medical use of the medicament and can be determined readily by the skilled artisan.
The medicament can take a variety of forms such as tablets, capsules, bulk or unit dose powders or granules; may be contained within liposomes; or may be formulated into solutions, emulsions, suspensions, ointments, pastes, creams, gels, foams or jellies. Parenteral dosage forms include solutions, suspensions and the like. The medicament is likely to contain any of a variety of art-recognized excipients, diluents, fillers etc. Such subsidiary ingredients include disintegrants, binders, lubricants, surfactants, emulsifiers, buffers, moisturizers, solubilizers and preservatives. The artisan can configure the appropriate formulation comprising TMS and seeking guidance from numerous authorities and references such as "Goodman & Gilman's The Pharmaceutical Basis of Therapeutics" (6th ed., Goodman et al., eds., MacMillan Publ. Co., NY, 1980).
In body sites that are characterized by continual cell growth or require cell growth inhibition because of dysfunction and are relatively inaccessible, TMS can be administered in a suitable fashion to assure effective local concentrations. For example, TMS may be injected in a depot or adjuvant, carried in a surgically situated implant or reservoir that slowly releases a fixed amount of TMS over a period of time or may be complexed to recognition molecules with the capability of binding to the site presenting with abnormal cell growth. An example of such a contemplated scenario is a recognition molecule that is an antibody with binding specificity for a bone marrow specific antigen wherein said marrow-specific antibody is complexed to TMS, said complex administered to a patient with leukemia.
While the invention has been described in detail and with reference to certain embodiments thereof, it would be apparent to one skilled in the art that various changes and modifications can be made without departing from the spirit and scope thereof. | The invention relates to a novel compound, compositions and medicaments thereof and a method of inhibiting cell proliferation, platelet aggregation (induced by various factors), and inhibiting malignant phenotypes of tumor cells such as those having a metastatic property, using said compound, composition or medicament. N,N,N-trimethylsphingosine shows superior cell proliferation inhibitory and anti-metastatic activity over related compounds. | 2 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an exposure apparatus used for manufacturing semiconductor devices and to a device manufacturing method using the exposure apparatus.
[0002] In recent years, large-scaled semiconductor manufacturing equipment and facilities have been built for the purpose of improving the production efficiency. In addition, to improve the operation efficiency of apparatuses, the operation time of semiconductor manufacturing apparatuses is getting longer. Under these circumstances, to prolong the operation time of semiconductor exposure apparatuses themselves, illumination lamps used for exposure have been examined to improve their service life. Although the service life of lamps is recently increasing, lamps are exchange components. To keep operating the apparatus, the lamp must be periodically exchanged, though the exchange period has become longer.
[0003] Conventionally, a lamp in a semiconductor exposure apparatus is turned on for a predetermined time and then turned off, and the operator waits for a predetermined time until the temperature of the lamp itself drops and then exchanges the lamp. Alternatively, the temperature of a lamp is always monitored, and the lamp is exchanged after a decrease in temperature of the lamp is confirmed.
[0004] However, in the method of exchanging the lamp after a predetermined time, the operator waits for the predetermined time independently of the temperature of the lamp. For this reason, the maintenance time (lamp exchange time) of the apparatus prolongs to waste the apparatus stop time, resulting in a decrease in apparatus operation efficiency. When the lamp temperature is always monitored, and the lamp is exchanged after confirmation of a decrease in lamp temperature, the operator devotes himself/herself to the apparatus whose lamp need be exchanged because the lamp temperature must be always confirmed without waiting for a predetermined time. This increases the load on the operator, resulting in a decrease in operation efficiency. In addition, since the temperature of a lamp at high temperature need be confirmed, the operator may get burnt during confirmation.
SUMMARY OF THE INVENTION
[0005] The present invention has been made in consideration of the above conventional problems, and has as its first object to provide an exposure apparatus whose operation efficiency is improved by minimizing the lamp exchange time and minimizing the device production stop time, and a device manufacturing method using the exposure apparatus. It is the second object of the present invention to allow an operator to confirm the lamp exchange time without devoting himself/herself to the apparatus requiring lamp exchange, thereby decreasing the operation load on the operator and improving the operation efficiency. It is the third object of the present invention to prepare an environment for ensuring safety during operation by preventing any accident such as burn even in case of operation error by the operator.
[0006] In order to achieve the above objects, an exposure apparatus of the present invention, or a device manufacturing method of manufacturing a semiconductor device using the exposure apparatus is characterized by the following arrangement.
[0007] An exposure apparatus having a maintenance door for an exposure illumination lamp comprises means for detecting temperature information of the lamp, means for confirming stop of an operation sequence of the exposure apparatus and outputting the confirmation result, and means for notifying an operator of an appropriate time for exchanging the lamp on the basis of the temperature information and the confirmation result.
[0008] With this arrangement, the operator can know the lamp exchange operation time by referring to the lamp temperature information without devoting himself/herself to the apparatus which requires lamp exchange. Hence, the lamp exchange time and apparatus stop time can be minimized, and the apparatus operation efficiency can be improved. In addition, since the exchange operation is started after the stop of the sequence is confirmed on the basis of the sequence stop information, the exchange operation can be performed without any risk of an accident even in case of operation error by the operator.
[0009] An exposure apparatus having a maintenance door for an exposure illumination lamp comprises means for detecting temperature information of the lamp, and means for notifying an operator of an appropriate time for exchanging the lamp on the basis of the temperature information.
[0010] With this arrangement, since the exchange operation is performed by opening the maintenance door in accordance with indication on the indicator, the operator can know the lamp exchange time and perform the exchange operation without devoting himself/herself to the apparatus that requires lamp exchange. Hence, the lamp exchange time and apparatus stop time can be minimized, and the apparatus operation efficiency can be improved.
[0011] Additionally, the exchange operation can be performed without any risk of burn even in case of operation error by the operator.
[0012] An exposure apparatus having a maintenance door for an exposure illumination lamp comprises lock means for the door, and the lock means actively locks or unlocks the door on the basis of a change in temperature in an ON or OFF state of the illumination lamp.
[0013] Since the door is locked or unlocked using only the energy generated by the shrinkage difference due to a “change in temperature” as a driving source of the lock means without receiving any external energy, the safety of exchange operation can be improved with an inexpensive arrangement.
[0014] A device manufacturing method comprises the steps of preparing an exposure apparatus, and manufacturing a device by exposure using the exposure apparatus.
[0015] According to this method, a device can be efficiently and safely manufactured by improving the efficiency and safety of lamp exchange.
[0016] According to a preferred aspect of the present invention, the exposure apparatus further comprises means for controlling a lock mechanism of the door on the basis of the detected temperature information.
[0017] According to a preferred aspect of the present invention, the lock mechanism of the exposure apparatus comprises an air cylinder as a driving source.
[0018] According to a preferred aspect of the present invention, the lock mechanism of the exposure apparatus comprises a DC actuator as a driving source.
[0019] According to a preferred aspect of the present invention, the exposure apparatus further comprises means for controlling a lock mechanism of the door on the basis of the detected temperature information.
[0020] According to a preferred aspect of the present invention, the means for detecting the temperature information in the exposure apparatus detects a temperature of the lamp or at a portion where the lamp is exchanged using a sensor as the temperature information.
[0021] According to a preferred aspect of the present invention, the lock means of the exposure apparatus actively locks or unlocks the door when a member shrinks or expands and deforms due to a change in temperature.
[0022] According to a preferred aspect of the present invention, the exposure apparatus further comprises means for detecting the change in temperature in the ON or OFF state of the illumination lamp, and means for notifying an operator of an appropriate time for exchanging the lamp on the basis of the detection result.
[0023] Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
[0025] [0025]FIG. 1 is a view showing the schematic arrangement of a semiconductor exposure apparatus according to the first embodiment of the present invention;
[0026] [0026]FIG. 2 is a view showing the positional relationship between the fixed portion and movable portion in a lamp exchange door of the lamp house of the semiconductor exposure apparatus shown in FIG. 1;
[0027] [0027]FIGS. 3A and 3B are views for explaining movement of the fixed and movable portions of the lamp exchange door;
[0028] [0028]FIGS. 4A and 4B are views showing movement of the movable portion of a semiconductor exposure apparatus according to the second embodiment of the present invention;
[0029] [0029]FIG. 5 is a block diagram showing the pneumatic pressure and electrical circuitries so as to explain processing by a temperature detection control section in the semiconductor exposure apparatus according to the second embodiment of the present invention;
[0030] [0030]FIG. 6 is a block diagram showing the electrical circuitries so as to explain processing by a temperature detection control section for controlling the movable portion of a semiconductor exposure apparatus according to the third embodiment of the present invention;
[0031] [0031]FIG. 7 is a flow chart showing a device manufacturing method using the exposure apparatus of the present invention; and
[0032] [0032]FIG. 8 is a flow chart for explaining the detailed flow of a wafer process of the device manufacturing method.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] Preferred embodiments of the present invention will be described in detail in accordance with the accompanying drawings.
[0034] First Embodiment
[0035] [0035]FIG. 1 is a view showing the schematic arrangement of a semiconductor exposure apparatus according to the first embodiment of the present invention. As shown in FIG. 1, the semiconductor exposure apparatus of the first embodiment comprises a projecting lens 7 for reducing and projecting a semiconductor pattern drawn on a reticle 6 , an X-Y stage 9 which moves while fixing a wafer 8 on which the semiconductor pattern is to be printed, an apparatus base plate 10 on which the X-Y stage 9 is mounted, a lamp 2 as a means for exposing the reticle 6 , a lamp house 1 in which the lamp 2 is fixed, a movable portion 3 for fixing the exchange door of the lamp house 1 , a sensor 4 for detecting the temperature in the lamp house 1 , an illumination unit 5 for guiding light emitted by the lamp 2 to the reticle 6 to illuminate the reticle 6 , a control section 11 for controlling the temperature detection operation in the lamp house 1 , and an indicator 12 for informing the operator on the basis of the output from the sensor 4 that the temperature in the lamp house 1 has reached room temperature. The apparatus also has a means (not shown) for confirming the stop of the sequence of the exposure apparatus main body and outputting stop information representing it.
[0036] [0036]FIG. 2 is a view showing the fixed portion of the lamp exchange door of the lamp house 1 . A fixed fitting 14 is attached to an exchange door 13 of the lamp house 1 . The movable portion 3 is attached to the inner wall of the housing of the lamp house 1 .
[0037] [0037]FIGS. 3A and 3B are views showing movement of the fixed fitting 14 and movable portion 3 of the lamp exchange door 13 . As shown in FIGS. 3A and 3B, a driving element 15 formed from two metal members 15 a and 15 b is attached to one end portion of the movable portion 3 . The movable portion 3 and driving element 15 are jointed at a pin joint P.
[0038] The metal members 15 a and 15 b have different thermal expansion coefficients. Letting α a be the thermal expansion coefficient of the metal member 15 a and α b b be the thermal expansion coefficient of the metal member 15 b, α b >α a holds. A barycenter G of the movable portion 3 is pivotally supported. The expansion amount difference between the metal members 15 a and 15 b is amplified by a lever function.
[0039] [0039]FIG. 3A shows the locked state of the exchange door 13 . When the lamp 2 is ON, and the temperature in the lamp house 1 rises to 100° C. or more, the metal member 15 b expands because the metal member 15 b has a larger thermal expansion coefficient than that of the metal member 15 a. Apparently, the driving element 15 curves and shrinks. The curve of the metal member 15 pulls up the joint P with respect to the movable portion 3 in a direction indicated by an arrow. For this reason, the movable portion 3 is fitted on the fixed metal portion 14 on the exchange door 13 , so the exchange door 13 is locked.
[0040] [0040]FIG. 3B shows the unlocked state of the exchange door. When the lamp is turned off, and the temperature of the lamp 2 and lamp house 1 decreases to room temperature (about 40° C.), the metal member 15 b shrinks. Apparently, the curve of the driving element 15 is canceled, so the entire driving element 15 expands to push the joint P down in a direction indicated by an arrow. In this state, the movable portion 3 is disengaged from the fixed fitting 14 on the exchange door 13 . The exchange door 13 is unlocked so it can be freely opened/closed.
[0041] A change in temperature is measured by the sensor 4 in the lamp house 1 and converted into an electrical signal. The electrical signal output from the sensor 4 is sent to the temperature detection control section 11 . The temperature detection control section 11 confirms whether the measured temperature in the lamp house 1 has reached the temperature (40° C. in this embodiment) at which the exchange door 13 is unlocked. When the temperature detection control section 11 confirms this temperature and stop information output from the means for outputting the stop information of the sequence of the exposure apparatus main body, it outputs a signal to cause the indicator 12 on the apparatus to indicate that the exchange door 13 can be opened. In this embodiment, the temperature at which the lamp house is locked is 100° C., and the temperature at which the lamp house is unlocked is 40° C. However, the present invention is not limited to these temperature conditions. The temperature conditions change depending on the thermal expansion coefficients of metal members used. In addition, the members of the driving element which shrinks to drive the movable portion are not limited to metal members. Polymer materials may be used as far as they generate a difference in deformation amount because of the difference in thermal expansion coefficient.
[0042] Second Embodiment
[0043] [0043]FIGS. 4A and 4B are views showing movement of the movable portion of an exposure apparatus according to the second embodiment of the present invention. The second embodiment is different from the first embodiment in that instead of driving a movable portion 3 using metals with different thermal expansion coefficients, an air cylinder is controlled in accordance with a signal from a temperature detection control section 11 on the basis of the detected temperature in a lamp house 1 .
[0044] As shown in FIGS. 4A and 4B, an air cylinder 17 is attached to one end of the movable portion 3 . A barycenter G of the movable portion 3 is pivotally supported. The movable portion 3 is jointed to the arm of the air cylinder 17 through a pin joint P. The expansion/retraction amount of the air cylinder 17 is amplified by a lever function. FIG. 4A shows the locked state of an exchange door 13 . FIG. 4B is the unlocked state of the exchange door 13 .
[0045] [0045]FIG. 5 is a block diagram showing the pneumatic pressure and electrical circuitries of the temperature detection control section 11 of the second embodiment. An analog electrical signal from a temperature detection sensor 4 attached in the lamp house 1 is amplified by a preamplifier section 18 and input to an A/D conversion section 19 . The input analog signal is converted into a digital signal by the A/D conversion section 19 , and the digital signal is sent to a control CPU 20 of the temperature detection control section 11 . The control CPU 20 reads the digital signal from the A/D conversion section 19 and detects the temperature in the lamp house 1 . When the input digital signal represents a temperature (100° C. or more) indicating the ON state of a lamp 2 , the control CPU 20 outputs a signal for fitting the movable portion 3 on the fixed metal portion 14 on the exchange door 13 to an electromagnetic valve driver 21 . On the basis of the input signal, the electromagnetic valve driver 21 operates an electromagnetic valve 22 to flow air to an air pipe 23 and retract the arm of the air cylinder 17 . When the arm of the air cylinder 17 retracts, the movable portion 3 is fitted on the fixed metal portion 14 on the door (FIG. 4A).
[0046] The temperature in the lamp house is measured by the sensor 4 . When the lamp 2 is turned off, and the temperature of the lamp 2 and lamp house 1 decreases to room temperature (about 40° C.), the digital signal input from the temperature detection sensor 4 to the control CPU 20 represents the temperature (about 40° C.) in the OFF state of the lamp 2 . When the control CPU 20 confirms that stop information is output from a means for outputting stop information of the sequence of the exposure apparatus main body, it outputs a signal for disengaging the movable portion 3 from the fixed metal portion 14 on the exchange door 13 to the electromagnetic valve driver 21 . On the basis of this signal, the electromagnetic valve driver 21 operates the electromagnetic valve 22 to flow air to an air pipe 23 reversely to the direction in which the arm of the air cylinder 17 retracts, and to expand the arm of the air cylinder 17 . When the arm of the air cylinder 17 expands, the movable portion 3 is disengaged from the fixed metal portion 14 on the door, so the exchange door 13 can be freely opened/closed. Simultaneously, the control CPU 20 reconfirms whether the measured temperature in the lamp house 1 has reached the temperature (40° C. in this embodiment) at which fixing of the exchange door 13 is canceled. When this temperature is detected, the temperature detection control section 11 outputs a signal for making an indicator 12 on the apparatus indicate it and also notifies the host CPU through a communication line 24 that preparation for lamp exchange is complete.
[0047] Third Embodiment
[0048] [0048]FIG. 6 is a block diagram showing the electrical circuitries so as to explain processing by a temperature detection control section for controlling the movable portion of a semiconductor exposure apparatus according to the third embodiment of the present invention. The third embodiment is different from the second embodiment in the means for driving a movable portion 3 . More specifically, in the second embodiment, the air cylinder is used as the driving source of the movable portion 3 . In the third embodiment, however, a DC actuator 25 is used. In this embodiment, the DC actuator 25 is attached to one end of the movable portion 3 . As in the second embodiment, a barycenter G of the movable portion 3 is pivotally supported, so a fine movement of the DC actuator 25 is amplified by a lever function.
[0049] In the arrangement shown in FIG. 6, an analog electrical signal from a temperature detection sensor 4 attached in a lamp house 1 is amplified by a preamplifier section 18 and input to an A/D conversion section 19 . The input analog signal is converted into a digital signal by the A/D conversion section 19 , and the digital signal is sent to a control CPU 20 of a temperature detection control section 11 . The control CPU 20 reads the digital signal from the A/D conversion section 19 and detects the temperature in the lamp house 1 . When the input digital signal represents a temperature (100° C. or more) indicating the ON state of the lamp, the control CPU 20 outputs a signal for fitting the movable portion 3 on the fixed metal portion 14 on an exchange door 13 to a DC actuator driver 27 (FIG. 6). On the basis of this signal, the DC actuator driver 27 operates the DC actuator 25 to retract the arm of the DC actuator 25 . An arm position sensor 26 is attached near the arm to detect whether the position of the arm of the DC actuator 25 is normal. When the control CPU 20 confirms on the basis of a signal from the arm position sensor 26 that the arm of the DC actuator 25 has retracted, it outputs a driving stop signal to the DC actuator driver 27 to stop driving the DC actuator 25 . With this operation, the arm of the DC actuator 25 retracts to fit the movable portion 3 on the fixed metal portion 14 on the door.
[0050] When the lamp 2 is turned off, and the temperature of the lamp 2 and lamp house 1 decreases to room temperature (about 40° C.), the digital signal input to the control CPU 20 represents the temperature (about 40° C.) in the OFF state of the lamp 2 . When the control CPU 20 confirms that stop information is output from a means for outputting stop information of the sequence of the exposure apparatus main body, it outputs a driving signal for disengaging the movable portion 3 from the fixed metal portion 14 on the exchange door 13 to the DC actuator driver 27 . On the basis of this driving signal, the DC actuator driver 27 operates the DC actuator 25 to expand its arm. When the control CPU 20 confirms on the basis of a signal from the arm position sensor 26 that the arm of the DC actuator 25 has expanded, it outputs a driving stop signal to the DC actuator driver 27 to stop driving the DC actuator 25 . With this operation, the movable portion 3 is disengaged from the fixed metal portion 14 on the door, so the exchange door 13 can be freely opened/closed. Simultaneously, the control CPU 20 reconfirms whether the measured temperature in the lamp house 1 has reached the temperature (40° C. in this embodiment) at which fixing of the exchange door 13 is canceled. When this temperature is detected, the temperature detection control section 11 outputs a signal for making an indicator 12 on the apparatus indicate it and also notifies the host CPU through a communication line 24 that preparation for lamp exchange is complete.
[0051] As the “actuator”, a solenoid for linearly driving the movable iron core in a coil can be used. In the third embodiment, an actuator using a DC power supply has been exemplified. However, a driving source using an AC power supply may be used. The present invention is not limited in respect to the attribute of a power supply. According to the third embodiment, since a small displacement can be amplified by the principle of a lever, a piezoelectric actuator or electrostatic actuator may be used.
[0052] Embodiment of Device Manufacturing Method
[0053] An embodiment of a device manufacturing method using the above-described exposure apparatus will be described next. FIG. 7 shows the flow of manufacturing a microdevice (e.g., a semiconductor chip such as an IC or an LSI, a liquid crystal panel, a CCD, a thin-film magnetic head, or a micromachine). In step 1 (circuit design), the pattern of a device is designed. In step 2 (mask preparation), a mask having the designed pattern is prepared. In step 3 (wafer manufacturing), a wafer is manufactured using a material such as silicon or glass. In step 4 (wafer process) called a preprocess, an actual circuit is formed on the wafer by lithography using the prepared mask and wafer. In step 5 (assembly) called a post-process, a semiconductor chip is formed from the wafer prepared in step 4 . This step includes processes such as assembly (dicing and bonding) and packaging (chip encapsulation). In step 6 (inspection), inspections including operation check test and durability test of the semiconductor device manufactured in step 5 are performed. A semiconductor device is completed with these processes and delivered (step 7 ).
[0054] [0054]FIG. 8 shows details of the wafer process (step 4 ). In step 11 (oxidation), the surface of the wafer is oxidized. In step 12 (CVD), an insulating film is formed on the wafer surface. In step 13 (electrode formation), an electrode is formed on the wafer by deposition. In step 14 (ion implantation), ions are implanted into the wafer. In step 15 (resist process), a resist is applied to the wafer. In step 16 (exposure), the circuit pattern of the mask is printed in each of a plurality of shot regions on the wafer by exposure using the above-described exposure apparatus or exposure method. In step 17 (development), the exposed wafer is developed. In step 18 (etching), portions other than the developed resist image are etched. In step 19 (resist peeling), the resist unnecessary after etching is removed. By repeating these steps, a multilayered structure of circuit patterns is formed on the wafer.
[0055] When the production method of this embodiment is used, a large-scaled device which is conventionally difficult to manufacture can be manufactured at low cost.
[0056] As has been described above, according to the present invention, the exposure apparatus comprises a means for detecting the lamp temperature information and a means for confirming stop of the sequence of the exposure apparatus main body and outputting stop information representing it, or a means for indicating information representing whether the door can be opened, on the basis of the temperature information. With this arrangement, the operation efficiency of the apparatus can be improved by minimizing the apparatus stop time. In addition, the operation load on the operator can be reduced to improve the operation efficiency. Furthermore, an environment for preventing any accident such as burn during operation can be prepared.
[0057] Also, since the exchange door lock mechanism unlocks the door on the basis of the temperature of the illumination lamp, safety in exchange operation can be improved with an inexpensive arrangement.
[0058] The present invention is not limited to the above embodiments and various changes and modifications can be made within the spirit and scope of the present invention. Therefore, to apprise the public of the scope of the present invention, the following claims are made. | An exposure apparatus having a maintenance door for an exposure illumination lamp includes device for detecting temperature information of the lamp, device for confirming stop of the operation sequence of the exposure apparatus and outputting the confirmation result, and device for notifying the operator of an appropriate time for exchanging the lamp on the basis of the temperature information and the confirmation result. The apparatus also has lock device for locking or unlocking the maintenance door on the basis of the temperature of the illumination lamp. | 6 |
FIELD OF THE INVENTION
The present invention relates in general to a method for continuously printing polychromatic designs on various materials, in particular woven carpets and the like, and a device for its realization.
BACKGROUND OF THE INVENTION
Similar known devices present the drawback that the printing of various colors is obtained in very distinct phases such that it is impossible to obtain particular chromatic effects in a small zone of the fabric due to the contemporaneous combination of several colors.
In other words, it is impossible to obtain particular tones or shades of colors using the above-mentioned known devices.
SUMMARY AND OBJECTS OF THE INVENTION
The primary scope of the present invention is to eliminate the above-mentioned drawback.
In accordance with the invention, this result is achieved by utilizing an operating method which involves:
horizontally moving the fabric to be dyed with a prearranged speed and direction;
drawing a predetermined amount of different colored liquid dyes from corresponding containers according to a prearranged sequence;
injecting the prearranged sequence of dyes onto a prearranged print on the fabric to be dyed in areas corresponding to predetermined adjacent points.
In order to realize the method, a device is utilized which has:
means for drawing a predetermined amount of liquid dyes from corresponding containers according to a prearranged sequence;
means for injecting the drawn dyes on the fabric to be dyed;
means for moving the fabric;
means for supporting the means for injecting the dyes.
The advantages derived from the present invention essentially consist in that it is possible to attribute the desired tones and shades of color to the points of the fabric with remarkable precision and according to a prearranged layout, which makes it possible to obtain pictorial and chromatic effects completely similar to those obtained by painting the same fabric by hand, that is, with high aesthetic quality and remarkable qualitative contents.
These and further advantages and characteristics of the present invention shall be better understood by all persons skilled in the art from the description below and with the aid of the attached drawings, which is given as partial simplification of the invention, but not to be considered in a limiting sense.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 represents a prospective view of a device for printing polychromatic designs in accordance with the invention;
FIG. 2 represents a prospective view of the means for injecting dyes of the device in FIG. 1;
FIG. 3 represents a prospective view of the means in FIG. 2 in arrangement of use.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reduced to its essential structure and with reference to the figures in the attached drawings, the method, according to the invention, for continuously printing polychromatic designs, has the following order of operating phases:
moving the fabric to be dyed with a prearranged speed and direction;
drawing a predetermined amount of different colored liquid dyes from corresponding containers according to a prearranged sequence;
injecting the prearranged sequence of dyes onto a prearranged print on the fabric in areas corresponding to predetermined adjacent points; and repeating the above steps to form a polychromatic design.
Advantageously, in accordance with the invention, it is provided that, after the phase of injecting the dyes, the cleaning of the dyed fabric or the setting of the injected color takes place. Thus, it is also provided that the image of the pictorial effect to be reproduced on the fabric is represented on a video monitor.
In accordance with the invention, to realize the method, the device provides:
means 3 for drawing a predetermined amount of liquid dyes of various colors from corresponding containers 1 according to a prearranged sequence;
means 2, 4, 5, 6, 8 for injecting the drawn dyes, on the fabric to be dyed, in areas corresponding to prearranged adjacent points;
means 12 for moving the fabric with a prearranged speed and direction;
means 9, 13 for supporting the above-mentioned means 2, 4, 5, 6, 8 for injecting the dyes.
According to a preferred embodiment of the invention, the means for drawing the liquid dyes from the respective containers 1 comprise connection tubes 3 between the containers 1 and corresponding distribution collectors 2 which supply the dyes to a plurality of multiple nozzles 6 . Each container has its own color and its own distribution collector 2. Each distribution collector 2 is aligned transversely with, respect to the sliding direction of the fabric to be dyed. Each multiple nozzle 6 is provided with several injectors 5. Each injector 5 of a nozzle 6 is connected to a different distribution collector 2 and receives a different color. Correspondingly each injector 5 injects a single color corresponding to a prearranged point of the material to be treated. FIG. 1 shows the invention with two colors, two connection tubes 3 and two distribution collectors 2. Correspondingly each nozzle 6 will have two injectors 5 and be able to combine the two colors in different portions to form a plurality of different shades of color on the fabric. Moreover, the means for the movement of the fabric preferably comprise a horizontal belt 12 which slides below the injectors 5.
The transfer of the dyes to the distribution collectors 2 can be advantageously carried out by means of pumps. Thus, the transfer can also advantageously be of the pressure type as well as the free drop from above type.
It is advantageously provided that the number of injectors 5 comprised in a multiple nozzle 6 is equal to the number of liquid dyes stored in the containers 1, thus making it possible to obtain any combination of the available colors at a prearranged point of the fabric according to prearranged proportions.
Moreover, it is advantageously provided that the supply of the liquid dyes to the multiple nozzles is regulated by means of a plurality of electrovalves 4 provided for each injector 5. The opening and closing times of which are controlled by means of an electronic control unit, for simplification not shown in the figures. Each of the electrovalves 4 being advantageously connected to its corresponding injector 5 by means of pipes 8. A support means for the connection tubes 3, and distribution collection 2 also has a rack 7 for accommodating the nozzles 6, which makes it possible to insert and unthread the nozzles 5 with extreme facility for providing their maintenance or replacement. The nozzles 6 are lined along the rack 7, and the rack 7 is positioned across the fabric. Each nozzle 6 has a plurality of injectors 5, and each injector 5 carries a different color from the container 1. A whole line across the fabric can then be covered with a plurality of different color combinations. It is also advantageously provided that an electronic exchange 12 is interfaced with a digital computer 14 for monitoring the course of the operating phases of the present method.
Moreover, means 10 for drying the belt 12 are provided upstream from the line of multiple nozzles 6, and means 9 for squeezing the treated material to facilitate the penetration of the color are provided downstream from the nozzles 6. To facilitate the cleaning of the fabric, means 11 for suctioning the excess colors are also provided downstream from the nozzles 6.
Moreover, display means are advantageously provided for representing, on a video monitor of the digital computer 14, the image of the pictorial effect to be reproduced on the fabric.
The operation is as follows:
An electronic unit administers the drawing of the dyes from the respective containers 1 according to a prearranged amount and according to prearranged colors. The dyes thus drawn are transferred to the distribution collectors 2, and the flow is regulated by means of the opening and closing of the electrovalves 4. Opening and closing times are controlled by a preprogrammed electronic unit. Since each injector 5 is linked with a different color conduit, it is possible to inject a prearranged amount of any desired color or color tone corresponding to a predetermined point on the fabric, by combining the colors proceeding from the above-mentioned conduits in the prearranged proportions. Therefore, at a predetermined point on the fabric, a polychromatic effect is obtained which may be different from that obtained other points of the same fabric by means of the injectors 5 of the other nozzles 6.
In practice, the details of execution can, however, vary in an equivalent manner in the shape, dimensions, arrangement of the elements, and type of materials used, without, moreover, going beyond the scope of the idea of the solution adopted and therefore remaining within the limits of the protection granted to the present patent for this invention. | To continuously print polychromatic designs on fabrics, a method is provided for horizontally moving the fabric with predetermined speed and direction, for drawing a prearranged amount of different colored liquid dyes, for applying the dyes of several colors to areas corresponding to predetermined adjacent points of the fabric in such a manner as to obtain particular chromatic effects due to the contemporaneous combination of several colors. The device comprises means for representing, on a video monitor, the image of the pictorial effect to be reproduced. | 3 |
BACKGROUND OF THE INVENTION
The prior art sequencing control circuits have included a number of different stepping relays which were electromagnetic relays capable of achieving a sequence of four different conditions of a motor and load. The load of the motor has included a garage door operator motor and the four conditions establish run up, stop up, run down and stop down of the raising and lowering type of garage door. The prior art electromagnetic relays were able to achieve these four functions and count control a reversing motor as well as controlling a lamp to illuminate the interior of the garage. The prior art had manual switches as inputs to the electromagnetic relays including a manual push button switch and a remotely controlled radio receiver switch. The transmitter controlling the receiver switch was often a hand-sized transmitter which would be located in the vehicle to be garaged. Such prior art garage door operators also had load switches such as up and down limit switches and torque or overload switches.
The prior art electromagnetic relays could also provide for a sequence of operation wherein if the garage door upon descending should strike a child or a pet animal, for example, the door would not merely stop due to overload, rather it also would move back toward an open position. This was a safety reverse feature during door closing. The prior art door operator circuits could also provide a time delay so that the lamp illuminating the garage could remain on for a period of one or two minutes even after the door had closed and the motor had been deenergized. Such prior art sequencing control circuits of the electromagnetic stepping relay type may be of the type illustrated in U.S. Pat. No. 3,719,005 issued Mar. 6, 1973.
The prior art door operator controls also included the type often used on commercial garage doors wherein a person had to maintain his finger on an "up" button or "down" button in order to have the door continue to move in the desired direction. If one ceased depressing the button the door would stop in a partially opened or closed condition. People familiar with this type of commercial garage door operator would often tend to hold their finger on the push button switch of a residential garage door operator for the entire time that the door was moving. In so doing this kept the actuating coil of the stepping relay energized, hence the ratchet mechanism was not released and the stepping relay was then incapable of responding to a load switch input, e.g. limit switch or torque switch. The same type of dangerous operating condition could occur if there was a short circuit in the push button wiring which would give a continuous input signal to the electromagnetic relay. This means that the door operator motor would not shut off when reaching the limit switch. An even more dangerous condition was that if the door were moving downwardly and a child got trapped under the door, the door would not reverse to move upwardly. If the radio transmitter in the automobile were left on the seat and a package placed on top of it this might depress the push button switch so that the transmitter emitted a continuous signal. This could cause the same type of dangerous condition. Also if a person entered the garage and accidentally knocked a rake or other tool to lean against the push button switch causing a continuous signal, this could also cause the same dangerous condition.
The door operator motor and garage door as a load connected thereto have inertia and in a typical garage door it takes about 0.3 to 0.6 of a second for the motor to accelerate the load to a condition of normal running speed in the motor. The torque switch is usually closed when the motor is at rest and the motor must accelerate to about half speed before this torque switch opens. Also the travel limit switches are often closed at the limit condition of the door and the door must move to release the closed condition of such limit switch. Thus there is a period of about 0.3 to 0.6 of a second wherein an input signal is provided by the torque switch or the limit switch. If a person merely depressed the push button switch for a fraction of a second which was less than the time period of 0.3 to 0.6 of a second, then the door operator circuit could obtain an additional input signal from the then closed limit or torque switch. This additional input signal would again actuate the electromagnetic stepping relay to the next condition which would be a door stopped condition. The person would then have to depress the push button three more times to get the door moving in the desired upward direction.
If the power were to be interrupted while the door was moving upwardly, for example, the door naturally would stop. When the power was restored and the push button again depressed, the door would not move in an upwardly direction instead it would move downwardly toward a closed condition. Accordingly, with the prior art electromagnetic relays, it would take two more depressions of the push button to get the door moving in the desired upward direction.
SUMMARY OF THE INVENTION
The invention may be incorporated in a sequencing control circuit for a door operator motor operable to open and close a garage door as controlled by signals from manual switch means and load switch means, said sequencing control circuit comprising, in combination, input means connecting said switch means to control energization of the motor, time delay means having a first time delay period and enabling means connecting said time delay means to said motor energization control means so that said time delay means enables control of the motor by a signal from said load switch means.
An object of the invention is to provide a sequencing control circuit which obviates the above-mentioned disadvantages of the prior art circuits.
Another object of the invention is to provide a sequencing control circuit for a door operator wherein enabling means is provided to enable control of the motor by a signal from load switches.
Another object of the invention is a sequencing control circuit which includes enabling means connected to disable control of the motor by a constant signal from a manual switch.
Another object of the invention is to provide a sequencing control circuit with a latch so that the control circuit is latched upon a momentary input control signal.
Another object of the invention is to provide a sequencing control circuit which always powers up a door operator control in the door closed motor stopped condition.
Other objects and a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic diagram of a sequencing control circuit for a door operator motor incorporating the invention;
FIG. 2 is a schematic diagram of the sequencer used in FIG. 1;
FIG. 3 is a schematic diagram of a latch circuit;
FIG. 4 is a schematic diagram of the integrated circuit used in the sequencer; and
FIG. 5 is a graph of logic voltages appearing at various points in the circuit of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 schematically illustrates a sequencing control circuit 20 for a motor 21 connected in a door operator 22 which in turn is connected to open and close a door 23. The door may be used for various purposes, for example to close access to a garage and the door operator may have a lamp 24 to illuminate the interior of the garage. The door 23 is shown as movable on a track 25 by means of a drive mechanism, not shown, but within the door operator 22 and this drive mechanism may move a carriage along a channel 26 to actuate a down limit switch 27 and an up limit switch 28.
The motor 21 includes a rotor 30 connected through a friction clutch 31 to the door operator 22. A torque or overload switch 29 is connected on the load side of the clutch 31 to be responsive to selective load conditions on the door 30. The motor 21 also includes stator windings 34 and 35 and a reversing capacitor 36. Energization terminals 37 and 38 are connected for energization from A.C. source 39 and energize the stator windings through a thermal overload device 40. A step down transformer 42 is connected for energization from the terminals 37 and 38 in order to provide a safe low voltage, e.g., in the order of 30 volts to the sequencing control circuit 20.
Input switch means are provided for the control circuit 20 and include a manual push button switch 44 and a transmitter push button switch 45. The switch 45 is provided in a radio transmitter 46 which when the switch 45 is actuated emits a radio signal. A radio receiver 47 is provided and if both radio receiver and transmitter are on the same code and frequency then a switch 48 in the receiver 47 will be closed. A terminal strip 49 includes terminals 51, 52 and 53. Terminal 53 is connected to the receiver 47 to supply an operating voltage thereto relative to terminal 51 which is the external ground 54.
The sequencing control circuit 20 is a multi-terminal device and in one embodiment manufactured in accordance with this invention was a printed circuit board with terminals thereon. This was a 16 terminal device but not all terminals required external connections. The terminals with external connections thereto are Nos. 1, 2, 3, 5, 6, 8, 9, 11, 12, 13 and 16.
FIG. 2 schematically illustrates the internal circuitry of the sequencing control circuit 20 with the same reference numerals on the terminals shown around the periphery of the circuit. This sequencing control circuit 20 includes a power supply 58 which includes a rectifier 59 supplying filtered D.C. on conductor 60 to output relays 60, 61 and 62 and to terminal 5 which supplies power to the radio receiver 47 via terminal 53. The power supply 58 also supplies filtered D.C. power to terminal V ss on a sequencer 64. The sequencer 64, described below, includes a number of gates, transistors and flip-flops and may be an integrated circuit. The power supply 58 has the same external ground 54 as is shown in FIG. 1. Thus circuits FIGS. 1 and 2 are negative ground systems whereas the sequencer 64 as described below is a positive ground circuit.
The relays 60-62 control contacts 66-68, respectively. When relay 60 is energized, contact 66 is closed to complete the circuit between terminals 11 and 16. As shown in FIG. 1 this will energize stator winding 34 directly and stator winding 36 indirectly through capacitor 36 for motor rotation in the direction illustrated as the up direction for door 23. Energization of relay 61 closes contact 67 for a connection between terminals 12 and 16 which will provide a down direction of rotation of the motor 21. Energization of relay 62 closes contact 68 for a connection between terminals 1 and 13 to illuminate the lamp 24.
Each of the relays 60-62 is provided with a driver transistor 70-72, respectively. The emitters of transistors 70-72 are connected to the external ground 54 with the collectors connected to the respective output relays 60-62, respectively. The bases of these transistors are connected to sequencer terminals respectively designated as UP, DN, and LP. When a base of a transistor is at the same potential as the emitter then such transistor is turned off. When the base is positive relative to the emitter, the transistor is turned on to energize its respective relay and thus establish the respective function of motor energization up or down or lamp energized.
The sequencer 64 has additional terminals including a limit terminal LIM, a lamp option input terminal OPT, an overload torque input TQ, a push button input PB, and a clock input CL. Each of these terminals is connected through a current limit resistor to sequencing control circuit terminals 6, 8, 9, 10 and 3, respectively. The sequencer 64 also includes a terminal V DD to supply operating voltages to some drains of FET transistors in the sequencer 64. A lamp delay disable terminal DIS is also provided in the sequencer 64 and these terminals V DD and DIS are connected to the external ground 54.
FIG. 4 is a schematic diagram of a sequencer 64 which may be used in the circuit of FIG. 2. This integrated circuit logic may take different forms and as shown in FIG. 4 the preferred embodiment includes many NOR gates, FET transistors of the PMOS type and various flip-flops. Two different types of FET transistors are shown, the enhancement-mode type illustrated with a single bar and the depletion-mode type with a double bar.
Input signals are provided at various terminals on the left side of FIG. 4, including terminals CL, PB, TQ and LIM. Output terminals are shown at the right side of FIG. 4 and include UP, DN, and LP to control the up and down condition of the motor 21 and the lamp 24.
Generally, the sequencer 64 includes a clock circuit 75, a divider or counter circuit 76, a GO circuit 77, a trigger circuit 78, a power-up circuit 79, a safety reversal circuit 80, an enable circuit 81, a lamp delay circuit 82 and an output circuit 83.
The clock circuit 75 obtains a timing frequency from some source and in this preferred embodiment the timing source is obtained from the clock terminal CL which is the commercially available power frequency. In the United States this is generally 60 Hertz. This incoming clock frequency is connected to a Schmitt trigger 101. An enhancement mode FET transistor 102 is connected at the input of the Schmitt trigger 101 to the negative operating voltage -V. As shown at the righthand side of FIG. 4, this negative operating voltage is the V DD for the drain voltage. V ss is the source voltage of some FET transistors connected to internal ground 86. This is different from the external ground 54 because the circuits of FIGS. 1 and 2 are negative ground circuits and the circuit of FIG. 4 is shown as a positive ground circuit so that negative logic applies in FIG. 4.
The Schmitt trigger 101 supplies a signal to the toggle input of a T flip-flop 103. This flip-flop is one of a sequence of flip-flops 103-116 in the divider circuit 76.
The GO circuit 77 includes an inverter 121 and another inverter 120 connected in series from the Q output of flip-flop 103 to one of two inputs of a NOR gate 119. Another input of this gate 119 is supplied from the output of the Schmitt trigger 101. The output of the NOR gate 119 is supplied on a conductor 87 to the set input S of an RS flip-flop 130, and the Q output thereof is connected to the data input of D of a type flip-flop 131. The Q output of this flip-flop is connected to the D input of a D type flip-flop 132. The push button input PB is connected through an inverter 129 to the reset input R of flip-flop 130. Also this push button input is biased to the internal ground 86 through a depletion-mode FET transistor 128. The gate of this transistor is also connected to internal ground. The GO circuit 77 further includes three input NOR gates 137 and 138 which together form a set-reset flip-flop. The GO signal appears on a GO signal conductor 88 which is connected to the reset terminals R of the flip-flops 105-112 and is also connected to an input of a NOR gate 136 connected in latch configuration to a four input NOR gate 135. The output from the NOR gate 135 is a trigger signal TRIG appearing on a trigger conductor 89, which supplies a trigger signal to the output circuit 83.
The enable circuit 81 includes a four input NOR gate 122 having inputs from the Q outputs of each of the flip-flops 108-111. The output from NOR gate 122 is supplied to one input of a NOR gate 133 and the other input is supplied from the Q output of flip-flop 132. The output of NOR gate 133 is supplied to one of four inputs of the NOR gate 135. Another input comes from the Q output of flip-flop 112. Still another input comes from the output of a NOR gate 134. An inverter 123 has an input from the Q output of flip-flop 109 and the output of inverter 123 is applied to one input of the NOR gate 134. Another input of NOR gate 134 comes from a conductor 90 from the output circuit 83.
The torque input TQ is an incoming signal coming from the torque switch 29 and is biased to ground through a depletion-mode FET transistor 141 in a manner similar to the push button input PB. The TQ signal is also applied through an inverter 142 to a reset input R of an RS flip-flop 143. The Q output of flip-flop 143 is applied to the data input D of a D type flip-flop 144. The Q output of flip-flop 144 is connected to one of four inputs of a NOR gate 172 in the reversal circuit 80.
The limit switch input LIM receives an input signal from the limit switches 27 or 28 and is biased to ground by a depletion-mode FET transistor 151 in a manner similar to the push button input PB. This limit switch input LIM is connected through an inverter 152 to a reset input R of an RS flip-flop 153. The Q output of this flip-flop is connected to the data input of a D type flip-flop 154. The Q output of this flip-flop is connected to a conductor 91 leading to the reversal circuit 80. The Q of flip-flop 154 is also connected to the reversal circuit 80.
The reversal circuit 80 includes the NOR gate 172 which has an output connected to the set input S of an RS flip-flop 173. This reversal circuit also includes enhancement mode FET transistors 145-149. The Q output of flip-flop 173 is connected to the gate of transistor 146. This transistor is connected to the internal ground 86 by the series connected transistors 148 and 149. The other end of transistor 146 is connected to a conductor 92. The transistor 145 is connected between this conductor 92 and the internal ground and a depletion-mode FET transistor 150 is connected between this conductor 92 and the operating voltage source -V. The transistor 147 is connected in parallel with the series transistors 148 and 149.
The power-up circuit 79 includes an enhancement-mode FET transistor 167 connected in series with a depletion-mode FET transistor 168 between -V and internal ground. At the junction between these two transistors the input of an inverter 169 is connected, the output of which is connected to reset terminals R of D flip-flops 170 and 171. The Q output of flip-flop 170 is connected to the data input D of flip-flop 171 and the Q output of this flip-flop is connected to the set inputs of flip-flops 155 and 156.
The trigger signal conductor 89 is connected through an inverter 139 to one of the inputs of the NOR gate 138. The conductor 89 is also connected through an inverters 139 and 140 to a conductor 94 which is connected to the reset terminals R of the flip-flops 143, 144, 153 and 154.
The output circuit 83 includes the previously mentioned T flip-flops 155 and 156 with the trigger conductor 89 connected to the toggle terminal T of the flip-flop 155. The Q output of this flip-flop is connected to the toggle terminal of the next flip-flop 156. The Q output of flip-flop 156 is connected to an input of a NOR gate 162 and the Q output of flip-flop 156 is connected to an input of another NOR gate 164. The Q output of flip-flop 155 is connected by a conductor 95 which is connected to the remaining inputs of NOR gates 162 and 164, is connected to the gate of transistor 147 and connected to one of the four inputs of the NOR gate 172.
The output of NOR gate 162 is connected to the gate of an enhancement mode FET transistor 163 with the source connected to internal ground and the drain connected to the output terminal UP and also connected through a resistor 97 to the voltage terminal -V. NOR gate 164 is connected to the gate of enhancement mode FET transistor 165, the source of which is connected to ground. The drain thereof is connected to the output terminal DN and is also connected through a resistor 98 to the operating voltage terminal -V.
The output circuit 83 is also provided with a regulator transistor 166 with the gate thereof connected to conductor 95, the source connected to internal ground and the drain connected to a regulator terminal R2 and also connected through a resistor 99 to the -V terminal.
There is also a lamp option input terminal OPT which is connected to a complex gate consisting of four transistors. These transistors include enhancement-mode FET transistors 157-159 and a depletion-mode FET transistor 160. It is the gate of transistor 158 which is connected to the option terminal OPT and through a depletion-mode FET transistor 161 to ground. Transistors 157 and 158 are connected in parallel to ground. Transistors 160 and 159 are connected in series with this parallel combination to the operating voltage -V. The gate of transistor 157 is connected to the Q output of flip-flop 156 and the gate of transistor 159 is connected to the Q output of flip-flop 155.
A lamp output may be considered as a part of the output circuit 83. This lamp output includes the lamp delay circuit 82 which has a two input NOR gate 124 supplying an inverter 125 in turn supplying the gate of an enhancement-mode FET transistor 126. This transistor is connected through a pull-up resistor 96 to the operating voltage -V and the source is connected to the internal ground. The junction between the resistor 96 and the transistor is connected to the lamp output terminal LP.
A lamp delay disable terminal DIS may be connected to the operating voltage -V, and is connected through an inverter 117 to the set input of the D flip-flop 116. This flip-flop has the D or data input connected to the operating voltage -V. The delay disable input terminal DIS is also connected through a depletion-mode FET transistor 118 to the internal ground. The output of NOR gate 124 is connected to a regulator transistor shown as an enhancement mode FET transistor 127. The drain of this transistor is connected to a regulator terminal R1 and is also connected through a pull-up resistor to the operating voltage -V. The source of this transistor is connected to the internal ground.
FIG. 3 illustrates the internal circuit of the RS flip-flop 130. It includes NOR gates 176 and 177 with a set input S to one input of gate 176 and this gate supplying the Q output, which in FIG. 4 is not used. The output of gate 176 is connected by a conductor 178 to an input of the NOR gate 177 and the output of this gate 177 is connected by a conductor 179 to an input of the gate 176 for a latch configuration. The output of gate 177 supplies the Q output of the flip-flop 130. Two reset input terminals R are connected to inputs to the NOR gate 177. In the circuit of FIG. 4 only one reset input is used in which case the other reset input terminal is connected to the internal ground 86. In FIG. 4 the flip-flops 143 and 153 are ones which use two separate reset terminals, and these would be flip-flops as illustrated in FIG. 3.
OPERATION
The sequencer 64 shown in FIG. 4 is a digital control circuit which may be an integrated circuit mounted on single chip of silicon. Since this chip may be quite tiny, for example 0.01 square inches, the power dissipating capabilities of such chip are small and typically may be 10 milliamperes at 15 volts. The circuit shown in FIG. 4 in this preferred embodiment is using PMOS technology and primarily using FET transistors. Negative logic is used to describe this PMOS technology because the operating voltage is a negative voltage, e.g. 15 volts relative to internal ground 86 which is zero volts. This means that the logic conditions of zero and one correspond to ground and -V, respectively.
Two different types of FET transistors are used with transistor 75, for example, being an enhancement-mode transistor and illustrated with a single bar connecting drain and source. Transistor 128, for example, is a depletion-mode FET transistor and illustrated in the drawing with a double bar connecting the drain and source. The enhancement-mode transistor such as transistor 75 has zero drain current for a zero source to gate voltage. The depletion-mode FET transistor on the other hand does have a definite conduction even at zero source to gate voltage and hence acts like a resistor permitting current flow therethrough.
The D or data flip-flops in the circuit of FIG. 4 such as flip-flops 131 and 132 are flip-flops with a toggle T and with data input D, and when the flip-flop gets a toggle input, the Q output goes to whatever the D input is at that time. The toggle flip-flops such as flip-flops 103-115 are ordinary flip-flops wherein the Q output changes each time there is a toggle input.
The RS flip-flops, such as 130 and 143, are reset to Q = 0 by a logic one on the reset terminal R. If the logic one remains on R, then when a logic one is applied to the set terminal S, Q changes from one to zero but Q cannot change to one. If the one R is removed, then when a logic one on is applied to S, this sets the flip-flop, and Q changes to a one.
Referring to FIG. 1, when the push button 44 is depressed or the radio receiver switch 48 is closed, this provides an input signal from these manual switch means to change the condition of the door operator motor 21. Assuming first that the door 23 is closed and the motor 21 is deenergized, then the sequence of operation is door opening, door open, door closing, and door closed. For the upward opening garage door this may be considered as run up, stop up, run down, and stop down. A truth table for the Q outputs of flip-flops 155 and 156 in FIG. 4 and the above four conditions is as follows:
______________________________________155 156 Condition______________________________________0 0 run up1 0 stop up0 1 run down1 1 stop down______________________________________
With A.C. source 29 supplying power, the sequencing control circuit 20 of FIG. 1 and FIG. 2 will control energization of the motor 21 and of the lamp 24. This A.C. source will supply power at a low voltage, e.g. 24 volts to terminals 2 and 3 of the sequencing control circuit 20. This in turn supplies lightly filtered D.C. power to energize the relays 60-62 and power to the radio receiver 47. Filtered D.C. power is also supplied at the V ss terminal of the sequencer 64. As shown at the right side of FIG. 4 this V ss terminal is the internal ground 86 so that the circuit of FIG. 4 is positive ground and the circuit of FIG. 2 is negative ground by the external ground 54.
Considering first the output circuit 83 of FIG. 4, the above truth table shows that in the stop down condition the Q outputs of both flip-flops 155 and 156 are in a logic one condition. Flip-flop 155 may be considered the run or stop flip-flop and flip-flop 156 may be considered the up or down flip-flop. In this preferred embodiment the motor 21 may be made to run in the run up condition by a trigger signal on the trigger conductor 89 which toggles flip-flop 155. This changes the Q output to a one which toggles the flip-flop 156 changing the Q output from a one to a zero. In the NOR gates shown in FIG. 4, conventional logic is used, that is, any logic one on an input creates a zero at the output thereof, and all zeroes on the input create a one on the output. This logic zero on the Q of 156 causes NOR gate 162 to change state to a logic one output. This turns on transistor 163. Previously, when the motor was deenergized, the output terminal UP was at a logic one condition because it was tied through pull-up resistor 97 to the operating voltage -V. Now that the transistor 163 is turned on, this UP terminal goes to a logic zero. Referring now to FIG. 2 this logic zero condition is internal ground which externally is the positive Dc voltage of the power supply 58. This positive voltage on the base of transistor 70 turns on this transistor 70 which in turn energizes relay 60 and closes contact 66. This makes a connection between terminals 11 and 16 and hence the motor rotor 30 runs in the up direction to open the door 23.
Similarly, for a run down condition of the door 23, the Q output of flip-flop 156 goes to a zero and Q of flip-flop 155 goes to zero. Thus NOR gate 164 output changes state to a logic one, transistor 165 turns on and the terminal DN goes to a logic zero turning on transistor 71 and relay 61 of FIG. 2 which closes the circuit between terminals 12 and 16. Accordingly what is wanted is a trigger signal on the trigger conductor 89 in order to get the flip-flops 155 and 156 to be toggled.
The manual switches 44 and 45 normally control the inputs to start the motor 21 and the load switches 27, 28 and 29 normally stop the motor, however, these functions may be reversed, for example, the manual switches 44 or 45 may also be used to stop the motor.
The sequencing control circuit 20 provides these functions in proper sequence and also controls the lamp 24 plus providing a lamp delay function. In addition, the sequencing control circuit 20 ignores obvious, unintentional or false commands such as shorted push button wiring or push buttons 44 or 45 held on for too long a time period, and permits normal functions of the limit and torque switches 27-29. The sequencing control circuit 20 does not respond to false noise commands that might be electrically or mechanically generated such as induced 60 Hertz voltage or contact bounce.
In FIG. 4 the clock frequency is shown as being obtained from the 60 Hertz power line. The Schmitt trigger 101 eliminates power line jitter so that induced voltage or other false noise commands do not affect the sequencer 64. The transistor 102 is a transistor which limits the input voltage to a few volts in excess of the operating voltage -V, which for example might be -15 volts. This assures that the integrated circuit voltage maximums are not exceeded.
The clock frequency from the clock circuit 75 is passed to the divider or timing counter circuit 76. This generates from the clock frequency all of the various time delay periods desired within the sequencer 64.
One-thirtieth of a second timing periods are generated from the Q output of flip-flop 103 and these are passed by the inverters 121 and 120 to NOR gate 119 which supplies the set pulses to the flip-flops 130, 143 and 153. These 1/30 of a second timing periods are used for noise rejection at the push button terminal PB, or the torque input TQ, and the limit input LIM. The Q output of flip-flop 104 provides 1/15 second period pulses to power-up reset flip-flops 170 and 171. The toggle-counter string of flip-flops 105-112 provides successively longer timing pulses. The flip-flop 108 has a timing period of about one second and since the pulse is one-half of the period this provides a one-half second timing pulse to NOR gate 122. The counters 109-111 are included in this timing so that only one pulse occurs in an eight and one-half second period. A timing pulse of about one second is provided from the counter 109 through inverter 123. Also from the Q output of flip-flop 112 a timing pulse of about 8.5 seconds is supplied to the NOR gate 135. The flip-flop 116 provides a timing pulse at the Q output of approximately 136 seconds. This is used for lamp deenergization delay.
The power-up circuit 79 is used to make certain that the sequencing control circuit 20 is always powered or energized in the stop down condtion of the motor 21. This is distinguished from the prior art electromagnetic relays. In such prior art systems, if the power were somehow interrupted during the run up condition of the motor and then power restored, the normally closed torque switch, similar to switch 29, would provide another impulse to the actuating coil of the electromagnetic stepping relay which would index the relay into the stop up condition, even though the door was partly up. The limit switch 27 is shown closed in FIG. 1, and it may or may not be closed, but if closed, it could create the same condition as the normally closed torque switch 29. Next if the push button 44 were depressed to start the motor, the motor would start in the run down mode, which could be a dangerous condition. The present sequencing control circuit 20 eliminates this hazard. As the A.C. source 39 is first applied to the step down transformer 42, the rectifier 59 would begin to conduct current and the capacitors in the D.C. filter would begin to charge. This means that the power supply of voltage -V is increasing as a ramp-like voltage. In FIG. 4 the power-up circuit 79 shows that this voltage -V is applied to transistor 167. Initially the output of inverter 169 is a logic one which resets the D flip-flops 170 and 171. The input to inverter 169 is a logic zero because the depletion mode transistor 168 conducts the ground and the enhancement mode transistor 167 is not conducting until the voltage -V increases to be more negative than the threshold voltage of transistor 167. The input to inverter 169 effectively remains a logic zero until this negatively increasing operating voltage -V increases to be more negative than the sum of the thresholds of transistor 167 and 169. During this time the flip-flops 170 and 171 are reset by a logic one on the reset inputs thereof so that the Q outputs of the flip-flops is a logic zero and thus Q of flip 171 is a logic one which is used as a power-up reset. This logic one goes to the two flip-flops 155 and 156 in the output circuit 83 thus setting them so that both Q outputs are ones. According to the truth table set forth above this is a stop down condition of the motor 21.
As the operating voltage -V further increases in negative magnitude, it becomes negative enough to overcome the thresholds of transistor 167 and inverter 169 and the input to inverter 169 effectively becomes a logic one, thus its output becomes a logic zero and no longer resets the flip-flops 170 and 171. However, they have previously been reset. The Q of flip-flop 171 remains a logic one which in addition to setting the flip-flops 155 and 156 also resets the flip-flop 173.
The D or data input of flip-flop 170 is connected directly to a logic one which is the -V voltage. The first negative transition of the 1/15 of a second pulse from the Q output of flip-flop 104 toggles flip-flop 170 to a one state at the Q output. This next negative transition of the 1/15 of a second line toggles the logic one now at the D input of flip-flop 171 to its Q output. The Q output which is the power-up reset is now a logic zero and remains a zero until the next time power is first applied. It will be noted that all flip-flops with toggle inputs or D inputs are clocked upon the negative going logic one transition of the toggle input.
The GO circuit 77 provides input noise rejection and debounce of input contacts. The PB, TQ and LIM inputs contain three identical noise rejection circuits but there is only one debounce circuit shared by all three inputs. The inverter 129, and flip-flops 130 and 131 are the noise rejection devices for the PB input. It will be noted that the radio receiver 47 is also connected to the push button PB input. In a similar manner inverter 142 and flip-flops 143 and 144 act for the TQ input and inverter 152 and flip-flops 153 and 154 act for the LIM input. Only the noise rejection of the PB input will be described.
The output of inverter 121 clocks data from flip-flop 130 into flip-flop 131. Also inverter 121 feeds inverter 120 which controls the NOR gate 119. The output of NOR gate 119 on conductor 87 makes the transition to logic one synchronized with inverter 121 but it is delayed by 1/120 of a second by the output of the Schmitt trigger 101. FIG. 5 shows a graph of the pulses making up the zero and logic one, with the logic one condition shown as negative of the zero because of the negative logic used in FIG. 4. The 1/60 of a second timing periods are shown from the output of the Schmitt trigger 101 and of course this means that the pulses are one-half of this or 1/120 of a second. FIG. 5 shows that the negative going transition of 119 is 1/120 of a second later than the negative going transition of the inverter 121. Thus the flip-flop 130 is set, as at point 180 on FIG. 5, during the last half of the logic one duration of inverter 121. NOR gate 119 is logic zero during the first half of the logic one of inverter 121 and during the logic zero of inverter 121.
A command at the push button input PB is in the form of a switch closure to external ground which is a switch closure to -V or a logic one. During switch open condition the depletion mode transistor 128 acts like a resistor and pulls the PB input, the input of inverter 129, to a logic zero thus the output of 129 is a logic one which resets the flip-flop 130. As long as there is a time when the push button input is a logic zero during the 1/60 of a second that inverter 121 is a logic zero, flip-flop 130 will be reset and inverter 121 will clock a logic zero into flip-flop 131. Thus no command will be recognized. A 60 Hertz or higher frequency noise signal can be imposed upon any of the PB, TQ or LIM inputs with no response, as established by the debounce circuit.
This is illustrated in FIG. 5 with a 60 Hertz noise pulse 181 appearing on the PB input. This causes the output of inverter 129 to go to a logic zero at the pulse 182. When the output of NOR gate 119 next goes negative at the negative transition 182', this sets the flip-flop 130 to a logic one at the negative transition 180 because the reset R of this flip-flop 130 has now been released. However, when the noise pulse disappears at time 183 the output of inverter 129 goes back to a logic one which resets the flip-flop 130 at time 184, so that the Q output is now a logic zero. Accordingly, when inverter 121 has the next negative going transition at time 185 and toggles flip-flop 131 the data input D to this flip-flop 131 is a logic zero so that there is no logic one condition toggled into flip-flop 131 as shown at the dotted line 186. Thus the Q of flip-flop 131 stays at logic zero. However, when a genuine input signal appears from the push button input PB as at time 187, the reset on flip-flop 130 is released, and the next time that the output of NOR gate 119 goes to a logic one this is set into the flip-flop 130 at time 188. 3/120 of a second later when the inverter 121 has the next negative transition at time 189 this logic one condition on the D input of 131 is toggled into flip-flop 131 as at time 190. The Q of flip-flop 131 will then be a zero. The Q of flip-flop 132 will have been a zero since flip-flop 132 is clocked by inverter 121 and therefore still contains a previous zero from flip-flop 131. Thus the NOR gate 137 is enabled by three zeroes on the inputs and the output of gate 137 will go to a logic one. This is a GO pulse on the conductor 88 and it resets the counters or flip-flops 105-112 and changes the NOR gate 136 to a logic zero which changes the NOR gate 135 output to a logic one. This is the trigger signal shown at 192 on FIG. 5 and is the trigger signal as mentioned above to change the state of the output circuit 83. This trigger pulse clocks the flip-flop 155 from a run to stop mode or from a stop to a run mode. If flip-flop 155 was clocked to a run mode, the output thereof clocks flip-flop 156 from an up to a down mode or from a down to an up mode. Meanwhile, 1/30 of a second after the GO signal became a logic one at time 191, the logic one in flip-flop 131 is clocked by inverter 121 into flip-flop 132, thus the NOR gate 137 changes state at time 193 and the GO signal is now a logic zero.
The inverter 139 and the NOR gate 138 prevent another GO equal logic one signal from happening until the trigger signal on conductor 89 is again a logic zero. Thus even if the PB input was then made a logic zero, from an open switch, and therefore flip-flops 130, 131 and 132 would again be zero, and then the switch was again closed, resulting in NOR gate 137 having two input logic zeroes, the output of NOR gate 138 would still be a logic one and would inhibit the GO signal.
The Q of flip-flop 132 goes to a logic zero when the PB is zero and tries to enable NOR gate 133 which would turn off NOR gate 135 and thus the trigger signal would be logic zero. The NOR gate 122 prevents gate 133 from going to a logic one for one-half second after the GO signal so that any command is not recognized more often than two times per second, thus the maximum sequence rate is two times per second.
The signals from TQ and LIM produce a GO by setting flip-flop 131 and resetting flip-flop 132 via the complex gate composed of driver or enhancement mode transistors 145 through 149 and the depletion mode load transistor 150. The TQ or LIM inputs can produce a GO signal only during the run mode since the Q output of flip-flop 155 feeds a logic one to the gate of transistor 147 to turn it on during a stop mode and neither a logic zero at transistor 149, which occurs when the TQ signal is a logic one, nor a logic zero at transistor 148, which occurs when the LIM input is a logic one, can produce a GO signal. Also the trigger signal at conductor 89 feeds transistor 145 via inverter 140 so that inputs at TQ or LIM cannot produce a GO for a minimum of the first one-half second of any run mode.
Safety reversal of the door 23 upon an overload condition during a run down mode is provided so that should a child or a pet animal become caught underneath the door, the door will not only stop but will reverse and return upwardly. This safety reversal is provided by the reversal circuit 80 which includes the four input NOR gate 172. The gate 172 is normally a logic zero output to not set flip-flop 173. The gate 172 has a logic one output if all four inputs are zero and this logic one output will set the flip-flop 173 if all of the following are true:
1. LIM input is a logic zero.
2. Flip-flop 156 is a logic one, signifying the down mode.
3. Flip-flop 155 is a logic zero, signifying a run mode.
4. TQ input is a logic one.
It will be noted that the LIM and TQ inputs are inhibited by the trigger signal on conductor 89 via inverters 139 and 140 which resets flip-flops 143, 144, 153 and 154, therefore preventing any LIM or TQ response during the first one-half second of run.
Now if a child should get caught underneath the door while it is descending, this will overload the clutch 31 causing it to slip and causing the torque switch 29 to close. This provides an input at TQ during run down and will produce a stop down mode for one-half second and then a run up mode for at least one-half second or until another command is recognized. The stop down mode was produced by the TQ input going to logic one, which set flip-flop 173, turning off transistor 146, thus making conductor 92 a logic one and this set flip-flop 131 and reset flip-flop 132 for a GO signal. The run up mode was produced because the flip-flop 173 was formerly a logic one and turned off transistor 146 producing a GO signal when the trigger signal on conductor 89 went to a logic zero and turned off transistor 145. The flip-flop 173 is reset by flip-flop 156 when in the logic zero or up mode.
The enable circuit 81 enables connecting a time delay to the motor energization control so that the time delay means enables control of the motor by a signal from the load switches which are the limit switches or torque switch. Also this enable circuit 81 disables control of the motor by a constant signal from any of the input switches which exceeds a first time delay period. In the preferred embodiment this first time delay period is set at about eight and one-half seconds in the run up mode as determined by the Q output of flip-flop 112, and is set at about one second in the run down mode as determined by the Q output of flip-flop 109.
If the PB input is a logic one continuously, such as might happen if a wire is short circuited to ground or a stuck transmitter, or a rake accidentally leaning against the push button 44, then the flip-flops 131 and 132 will remain at a Q output of logic one and will not be able to turn off the gate 135 nor the trigger signal at conductor 89. The Q output of flip-flop 112 feeds the NOR gate 135 so that after eight and one-half seconds the trigger signal will become a logic zero no matter what else happens and then the TQ or LIM input signals can be recognized by the sequencer 64. This occurs as shown on FIG. 5 at time 194. The inverter 123 and NOR gate 134 provide the same function after only one second if the sequencer is in the down mode. This one second override of the PB input signal in the down mode allows reversal upon TQ equaling a logic one after only about seven inches of door movement for a typical garage door operator. A continuous PB input signal equaling a logic one will not produce two trigger signals on conductor 89 even if the power is turned off and then turned back on. By this enable circuit, the door cannot run past the limit switches with the switches having no affect on the circuit. This would be a dangerous condition and was possible with the prior art arrangements.
The lamp 24 may be controlled in a variety of manners including time delay of the deenergization or no delay. The normal lamp output to the output terminal LP is through a gate and transistor configuration similar to the up or down signal to operate the motor. Normally the lamp is turned off by logic zero condition on conductor 93. The depletion-mode transistor 160 acts as load or pull up resistor to attempt to keep conductor 93 at the -V voltage or logic one. However from the above truth table in the stop down condition the two Q outputs of flip-flops 155 and 156 are at logic one. This is the condition when the system is at rest for a long time with the door closed. This turns on transistors 157 and 159 pulling conductor 93 to a logic zero. Thus the NOR gate 124 has two zero inputs for a logic one output and a logic zero output of inverter 125. This turns off transistor 126. If this transistor is off the lamp 24 is off, because then the lamp output terminal LP is at negative voltage -V and this is applied, on FIG. 2, to the base of transistor 72. This -V voltage is the same as external ground which is the same as the emitter voltage hence transistor 72 is turned off and so relay 62 is not energized and the lamp 24 is not energized.
Now if the conductor 93 goes to a logic one condition this will turn on the lamp 24. Conductor 93 goes to a logic one, according to transistors 157, 158 and 159 if:
1. Output circuit 83 is in the run mode, which makes flip-flop 155 Q output go to zero turning off transistor 159, or
2. Output circuit 83 is in the stop mode and the lamp option input terminal OPT is not connected to -V.
If the circuit is in the stop-up mode, then the lamp is on because Q of flip-flop 155 is a one but the Q of flip-flop 156 is a zero which turns off transistor 157 making conductor 93 a logic one. This one on the input of NOR gate 124 makes its output a logic zero, the output of inverter 125 is a logic one and this turns transistor 126. As seen above this turns on the lamp 24. The lamp is also on for the stop down mode but in this mode the time delay of about one hundred thirty six seconds is in operation. For the stop down mode the above truth table show that the Q of flip-flops 155 and 156 are a one which turn on both transistors 157 and 159. This makes conductor 93 a zero and thus the reset on the flip-flops 113 to 116 is released. This permits these flip-flops to start to count the period of about one hundred thirty six seconds. At the end of this time period the flip-flop 115 toggles flip-flop 116 and this clocks the data input into the Q output which is a -V voltage. Thus the Q output goes to a logic zero and with two zeroes on the input of NOR gate 124 the output goes to a one, the output of inverter 125 goes to a zero and this turns off the transistor 126 to turn off the lamp 24. This above description assumes that the lamp option input OPT is not connected to -V. The -V is the same as external ground, and FIGS. 1 and 2 show this OPT terminal externally grounded, but this is optional.
If it is connected to -V, this turns on transistor 158 so that transistor 157 is ineffective and 157 is controlled by the down mode condition from flip-flop 156. Also the lamp delay disable terminal DIS must be connected to the -V in order to have the lamp deenergization delay. This -V at terminal DIS passes through the inverter 117 to be a logic zero on the set terminal S of flip-flop 116 and thus has no affect. If the terminal DIS is not connected to -V then the input to inverter 117 is connected to internal ground through transistor 118 so that the output of inverter 117 is a logic one and this hard sets the flip-flop 116 so that the delay is always zero.
The regulator transistor 127 operates from the output of gate 124 so that this transistor is turned on whenever transistor 126 is turned off and this eliminates the need for external voltage regulation because the silicon chip on which the sequencer 64 is mounted will then have substantially constant current regardless of whether the lamp is on or off.
The regulator transistor 166 operates in a manner similar to regulator transistor 127, and is turned on whenever the transistors 163 and 165 are off. This maintains substantially constant current on the chip to eliminate need for external voltage regulation.
The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of the circuit and the combination and arrangement of circuit elements may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed. | A sequencing control circuit is provided for a door operator motor which is connected to open and close a garage door as controlled by signals from manual switches and load switches. The sequencing control circuit includes time delay means with a first time delay period in the order of six to eight seconds. This permits a person to hold a push button switch closed for about six to eight seconds so that a slab door may be opened against a snow drift which otherwise would have so much torque requirement on the motor that an overload switch would stop the motor. Enabling means is provided to enable the motor during this time period yet to disable the constant signal from the push button for periods longer than this time delay period so that the door operator motor then is responsive to signals from the load switches.
The sequencing control circuit also includes a latch circuit having an output in a feed back loop to maintain the latch circuit latched upon a momentary input control signal. This allows time for the motor to accelerate the load to a normal running condition and to open any closed limit switch or closed torque switch during this acceleration period. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to new chemical compounds, which are of value as antibacterial agents and beta-lactamase inhibitors. More particularly this invention provides certain 2-oxo-1,3-dioxol-4-ylmethyl esters of penicillanic acid 1,1-dioxide (sulbactam).
U.S. Pat. No. 4,234,579 discloses penicillanic acid 1,1-dioxide, and certain esters thereof readily hydrolyzable in vivo, as antibacterial agents and beta-lactamase inhibitors. In particular, U.S. Pat. No. 4,234,579 discloses esters of the formula ##STR1## wherein R 1 is 3-phthalidyl, 4-crotonolactonyl, gamma-butyrolacton-4-yl or a group of the formula ##STR2## wherein R 2 and R 3 are each hydrogen, methyl or ethyl and R 4 is alkyl of 1 to 6 carbons. Said esters of formula I are readily cleaved in vivo to liberate penicillanic acid 1,1-dioxide.
However, it is an object of this invention to provide a new genus of esters of penicillanic acid 1,1-dioxide which hydrolyze readily in vivo to liberate penicillanic acid 1,1-dioxide. Specifically these new esters of penicillanic acid 1,1-dioxide are certain 2-oxo-1,3-dioxol-4-ylmethyl esters.
Certain 2-oxo-1,3-dioxol-4-ylmethyl esters of ampicillin are disclosed in published European patent application No. 39,086.
SUMMARY OF THE INVENTION
This invention provides novel esters of penicillanic acid 1,1-dioxide of the formula ##STR3## wherein R is selected from the group consisting of hydrogen, methyl and phenyl.
Said compounds of formula II readily hydrolyze to penicillanic acid 1,1-dioxide in vivo, and therefore they are useful as antibacterial agents and beta-lactamase inhibitors.
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to the novel compounds of formula II, and throughout this specification they are referred to as derivatives of penicillanic acid, which is represented by the structural formula ##STR4## In formula III, broken line attachment of a substituent to the bicyclic nucleus indicates that the substituent is below the plane of the bicyclic nucleus. Such a substituent is said to be in the alpha-configuration. Conversely, solid line attachment of a substituent to the bicyclic nucleus indicates that the substituent is attached above the plane of the nucleus. This latter configuration is referred to as the beta-configuration.
Also, in this specification, certain compounds are named as derivatives of 4-methyl-2-oxo-1,3-dioxole, the compound of formula IV. Moreover, the term 2-oxo-1,3-dioxol-4-ylmethyl is used for the radical of formula V. ##STR5##
The compound of formula IV is named 4-methyl-1,3-dioxolen-2-one, and the radical V is named (2-oxo-1,3-dioxolen-4-yl)methyl, in published European patent application No. 39,086.
The compounds of formula II can be prepared directly from penicillanic acid 1,1-dioxide by esterification. Thus the compounds of formula II can be prepared by reacting a compound of the formula ##STR6## with a carboxylate salt of penicillanic acid 1,1-dioxide of the formula ##STR7## wherein R is hydrogen, methyl or phenyl, X is a good leaving group, and M is a carboxylate salt forming cation. Useful leaving groups for X are halogen atoms, such as chloro, bromo and iodo, and useful carboxylate salts for compound VII are alkali metal salts, such as sodium and potassium salts, amine salts, such as triethylamine salts, and tetraalkylammonium salts, such as tetra-n-butylammonium salts.
The reaction between a compound of the formula VI and a compound of formula VII is usually carried out by contacting the reagents in an organic solvent, at a temperature in the range from 0° to 80° C., and preferably from 30° to 60° C. The compounds of formulae VI and VII are normally contacted in equimolar proportions, but an excess of either compound can be used. A wide variety of solvents can be used, and typical solvents are low-molecular weight ketones, such as acetone and methyl ethyl ketone, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and hexamethylphosphoramide. The reaction time varies according to a number of factors, but at about 55° C. reaction times of a few hours, e.g. 12 to 24 hours are commonly used.
The compound of formula II can be isolated by conventional methods. For example, the reaction mixture can be filtered and then the solvent removed by evaporation in vacuo. The residue is then partitioned between water and a water-immiscible, volatile, organic solvent, such as ethyl acetate. The ethyl acetate layer is dried and evaporated to afford the compound of formula II.
The compounds of formula II can be purified by conventional methods, such as recrystallization and/or chromatography.
The compounds of formula VI can be prepared by the methods described in published European patent application No. 39,086.
As indicated hereinbefore, the compounds of formula II are readily hydrolyzed in vivo to liberate penicillanic acid 1,1-dioxide, and therefore they can be used for the same purposes as the esters of penicillanic acid 1,1-dioxide readily hydrolyzable in vivo disclosed in U.S. Pat. No. 4,234,579. In particular, the compounds of formula II are formulated in the same way, they are administered by the same methods and routes to the same hosts, and they are administered at the same dosages as the esters of penicillanic acid 1,1-dioxide readily hydrolyzable in vivo disclosed in U.S. Pat. No. 4,234,579.
The following Examples and Preparations are provided solely for further illustration. Nuclear magnetic resonance (NMR) spectra were measured at 60 MHz. The following abbreviations for peak shapes are used: s, singlet; d, doublet; t, triplet.
EXAMPLE 1
5-Methyl-2-oxo-1,3-dioxol-4-ylmethyl Penicillanate 1,1-Dioxide
To a stirred suspension of 3.07 g of sodium penicillanate 1,1-dioxide and 2.33 g of 4-bromomethyl-5-methyl-2-oxo-1,3-dioxole in 100 ml of acetone was added 200-300 mg of tetra-n-butylammonium bromide, and then the reaction mixture was heated under reflux overnight. The reaction mixture was filtered hot, and the resulting solution was evaporated in vacuo. The residue was dissolved in ethyl acetate and the resulting solution was washed with dilute aqueous sodium chloride solution. The ethyl acetate solution was dried and evaporated in vacuo, and then the residue was chromatographed on silica gel using 1:1 hexane-ethyl acetate. The product-containing fractions were combined and evaporated in vacuo, and the residue was recrystallized from ethyl acetate-petroleum ether to give 2.80 g of the title product as a crystalline solid, m.p. 141.5°-2.5° C.
The NMR spectrum of the product (CDCl 3 ) showed absorptions at 1.55 (3H, s), 1.63 (3H, s), 2.20 (3H, s), 3.46 (2H, d, J=3 Hz), 4.40 (1H, s), 4.45 (1H, t, J=3 Hz) and 4.97 (2H, s) ppm downfield from tetramethylsilane. The infrared spectrum (KBr disc) showed absorptions at 5.46, 5.58 and 5.67 microns. The mass spectrum showed peaks at m/e 345, 280, 239, 212, 168, 111 and 83 (100%).
Analysis: Calcd. for C 13 H 15 O 8 NS: C, 45.21; H, 4.38; N, 4.06. Found: C, 45,36; H, 4.49; N, 4.03.
EXAMPLE 2
By repeating the procedure of Example 1, but replacing the 4-bromomethyl-5-methyl-2-oxo-1,3-dioxole by an equimolar amount of 4-bromomethyl-2-oxo-1,3-dioxole and 4-bromomethyl-5-phenyl-2-oxo-1,3-dioxole, respectively, the following compounds can be prepared:
2-oxo-1,3-dioxol-4-ylmethyl penicillanate 1,1-dioxide and
5-phenyl-2-oxo-1,3-dioxol-4-ylmethyl penicillanate 1,1-dioxide, respectively.
PREPARATION 1
4-Bromomethyl-5-methyl-2-oxo-1,3-dioxole
To a stirred solution of 3.0 g of 4,5-dimethyl-2-oxo-1,3-dioxole in 100 ml of carbon tetrachloride was added 4.63 g of N-bromosuccinimide. The resulting solution was heated under reflux and irradiated for 15 minutes. The reaction mixture was cooled to 0°-5° C., filtered and evaporated to give the title product.
The NMR spectrum (CDCl 3 ) showed absorptions at 2.05 (5% of starting material), 2.18 (3H, s), 4.30 (2H, s) and 4.35 (5% of dibromo compound) ppm downfield from tetramethylsilane. The infrared spectrum showed an absorption at 5.49 microns.
PREPARATION 2
4,5-Dimethyl-2-oxo-1,3-dioxole
A solution of phosgene (12.18 g) in cold dichloromethane was added dropwise to a cold solution of 3-hydroxy-2-butanone (10.83 g) and 16.38 g of N,N-dimethylaniline in 50 ml dichloromethane. The resulting green solution was stirred 2 hours at 0°-5° C. The solution was then evaporated to give an oil which was heated at 160°-190° C. for 30 minutes. The cooled reaction mixture was partitioned between water and ether. The separated aqueous layer was further extracted with ether and the combined organic extracts were dried and concentrated. The residue was triturated with pentane to give 3.53 g (25%) of a white crystalline solid, m.p. 76°-78° C.
The NMR spectrum of the product (CDCl 3 ) showed an absorption at 2.05 (s) ppm downfield from tetramethylsilane. The mass spectrum showed peaks at m/e 114, 56 and 43 (100%). | Certain novel 2-oxo-1,3-dioxol-4-ylmethyl esters of penicillanic acid 1,1-dioxide (sulbactam) hydrolyze readily in vivo to liberate the corresponding free acid. The novel esters of this invention are useful therefore as antibacterial agents and beta-lactamase inhibitors. | 2 |
BACKGROUND OF THE INVENTION
This invention relates generally to off-road motor vehicles, such as tractors, and more particularly, to an engine hood enclosure for the tractor engine in which the hood is rearwardly pivotable and is latchable in an intermediate opened position and a fully opened position.
Tractors, particularly tractors used in an agricultural environment, are typically provided with a hood enclosure that has pivotable parts to provide access to the engine for service thereof. Generally, tractor hoods do not utilize engine hoods that pivotally move as an entire unit to provide access to the tractor engine; however, one piece hood configurations can be more economically produced.
In known engine hood configurations, access for daily maintenance components is attained merely by lifting or removing a side panel of the engine hood. Furthermore, raising the hood to fully expose the engine subjects the hood to wind forces, while daily maintenance, such as oil level checking, etc., can be accomplished without fully raising the hood relative to the engine. Accordingly, it would be desirable to provide a rearwardly pivotable engine hood for a tractor in which the hood is positionable in at least one intermediate position.
Economical manufacture of a one piece engine hood enclosure is a desirable goal. One piece polymer hoods have the advantage of being molded in an aesthetically pleasing shape; however, certain manufacturing processes require the hood to have substantially uniform material thicknesses to accomplish a high gloss exterior finish and minimize tooling costs. Accordingly, no bosses can be molded into the body of the hood to enable the fastening of mounting components, such as the hinge for pivotally mounting the hood to the chassis. Accordingly, it would be desirable to provide a hinge and a process for mounting the hinge to the body of the hood to facilitate the use of a one piece polymer tractor engine hood.
Similarly, the problem of latching the engine hood in a closed position is amplified by an engine hood configuration that does not provide mounting bosses. Furthermore, the latch mechanism must be adjustable to enable the mating latch components to interengage in the prescribed manner. The location for mounting the latch must be structurally sound and is preferably accessible from either side of the tractor. Likewise, the hinge mechanism must also be adjustable to enable a proper and desirable mating of the engine hood to the tractor chassis or other related component.
Accordingly, it would be desirable to provide a one piece engine polymer hood for tractors, while providing solutions to the problems of pivotally mounting the hood, latching the hood and restricting the pivotal movement thereof.
The pivotal raising of a one piece hood requires the assistance of a spring assist mechanism to counterbalance the weight of the hood and facilitate the manual lifting of the hood. Gas springs can be utilized to offset the weight of the hood; however, gas springs often lose gradually the nitrogen gas from inside the spring. As a result, the force exerted by the spring lessens and causes the raising of the hood to become more difficult. Accordingly, it would be desirable to provide a mounting mechanism that could be adjustable to accommodate the changes in spring force and extend the operative life of the gas spring.
SUMMARY OF THE INVENTION
It is an object of this invention to overcome the aforementioned disadvantages of the prior art by providing a one piece polymer hood to enclose the engine compartment of a tractor.
It is another object of this invention to provide a hinge mechanism, a latching apparatus and a position control mechanism for a one piece polymer engine hood manufactured without mounting bosses.
It is still another object of this invention to provide a mechanism to limit the extent of pivotal movement of the engine hood to provide at least two opened positions to expose the engine to various degrees of exposure.
It is a feature of this invention that the mechanism for limiting the pivotal movement of the engine hood includes a slide mechanism having first and second slotted openings interconnected by a passageway to provide an intermediate opened position offering only limited exposure to the tractor engine.
It is an advantage of this invention that the mechanism for limiting the pivotal movement of the engine hood requires manual manipulation to move the slide mechanism to allow the further movement of the engine hood to the fully opened position.
It is another advantage of this invention that the slide mechanism allows sufficient pivotal movement of the engine hood to gain access to all of the maintenance items requiring daily service, yet minimizes the exposure of the engine hood to wind forces by keeping the engine hood at a lower profile.
It is still another object of this invention to provide a mechanism for limiting the pivotal movement of a one piece polymer hood for an agricultural tractor which is durable in construction, inexpensive manufacture, carefree of maintenance, facile in assemblage, and simple and effective in use.
It is yet another object of this invention to provide a latching mechanism that can be operable with a one piece polymer tractor hood.
It is still another feature of this invention that the latching mechanism is adjustable to enable the mating latch components to interengage in a prescribed manner.
It is still another advantage of this invention that the latching mechanism is mounted on a one piece polymer tractor hood in a manner to be structurally sound and accessible from either side of the tractor.
It is a further object of this invention to provide an adjustable latching mechanism for an agricultural tractor which is durable in construction, inexpensive manufacture, carefree of maintenance, facile in assemblage, and simple and effective in use.
It is yet another object of this invention that the hinge mechanism can be integrated into the one piece tractor hood design in a strong and cost effective manner.
It is yet another advantage of this invention that the hinge support is movable to provide adjustment of the tractor hood in a side-to-side manner.
It is yet another feature of this invention that the hinge support includes a portion pivotable about a center pin and secured by a pair of bolts to provide a side-to-side adjustment of the one piece hood member.
It is a further feature of this invention that the hinge support includes an lower portion fixed to the block of the tractor engine and an upper portion pivotally supported on the lower portion to provide side-to-side adjustment.
It is a further object of this invention to provide a mechanism for pivotally supporting a one piece tractor hood from a tractor chassis to provide side-to-side adjustment thereof, which is durable in construction, inexpensive manufacture, carefree of maintenance, facile in assemblage, and simple and effective in use.
It is still a further object of this invention to provide a mounting mechanism for gas springs counterbalancing the weight of the tractor hood enclosure that is adjustable to increase the mechanical advantage of the gas spring as the spring force weakens over time.
It is still a further feature of this invention that the mounting bracket is provided with a plurality of mounting positions that vary the moment arm through which the spring force is exerted to offset the weight of the hood.
It is a further advantage of this invention that the operative life of the gas spring as part of a hood lift mechanism is increased.
It is still a further advantage of this invention that the gas spring can be re-mounted in an alternative mounting position to maintain a substantially constant counterbalancing force as the gas spring weakens over time.
It is yet another feature of this invention that the re-mounting of the gas spring to alternate mounting positions can be accomplished without providing additional parts.
It is yet a further object of this invention to provide an adjustable mounting mechanism for the gas spring forming part of a hood lift mechanism which is durable in construction, inexpensive manufacture, carefree of maintenance, facile in assemblage, and simple and effective in use.
These and other objects, features, and advantages are accomplished according to the instant invention by providing pivotally mounted hood for a tractor wherein a gas spring, provided to offset the weight of the hood to facilitate the movement of the hood between opened and closed positions, is mounted to the chassis via a multi-position bracket having more than one hole therein for the selective connection of the gas spring. The bracket holes are arranged in a configuration defining a progressively increasing distance from the pivot connecting the hood to the chassis, thereby providing alternative mounting positions for the gas spring which have different moment arms for the application of the force exerted by the gas spring about the hood pivot. The gas spring can be remounted to a hole providing a larger moment arm relative to the hood pivot as the gas spring weakens over time due to the loss of gas therefrom, which enables the effective spring force offsetting at least a portion of the weight of the hood to remain substantially constant even though the gas spring weakens.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages of this invention will be apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a side elevational view of a tractor incorporating the principles of the instant invention;
FIG. 2 is an enlarged top plan view of the hood enclosure shown in FIG. 1, the engine and various mounting components for the hood being shown in phantom;
FIG. 3 is an exploded perspective view of the hood enclosure shown in FIG. 2, the hood and components bonded thereto being separated from the chassis mounting subframe and hinge support;
FIG. 4 is a simplified top plan view of the hood enclosure similar to that of FIG. 2, the side-to-side adjustment movement of the hood from the hinge support being shown in phantom;
FIG. 5 is a cross-sectional view taken along lines 5--5 of FIG. 4 to depict the details of the hinge support, the structure to which the hinge support is mounted being shown in phantom;
FIG. 6 is an enlarged detail view of the slotted bolt connection allowing a pivotal movement of the hinge support for side-to-side adjustment of the hood, as shown in phantom;
FIG. 7 is a side elevational view of the hood enclosure shown in FIG. 2, most of the side portion of the hood being broken away to better show the various mounting components and chassis subframe;
FIG. 8 is a schematic side elevational view of the hood shown in FIG. 7 with the hood raised to an intermediate opened position;
FIG. 9 is a schematic side elevational view of the hood similar to that shown in FIG. 8, but with the hood raised to a fully opened position;
FIG. 10 is a schematic side elevation view of the hood enclosure in the closed position and depicting the alternate mounting positions of the gas spring counterbalancing the weight of the hood and the resultant changes in the moment arm through which the spring force is applied; and
FIG. 11 is a schematic side elevation view of the hood enclosure similar to that of FIG. 10, except with the hood moved to the fully opened position and depicting the alternate mounting positions of the gas spring counterbalancing the weight of the hood and the resultant changes in the moment arm through which the spring force is applied.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and, particularly, to FIGS. 1-3, a representative view of an agricultural tractor incorporating the principles of the instant invention can best be seen. Left and right references are used as a matter of convenience and are determined by standing at the rear of the tractor and facing the forward end in the normal direction of travel. The tractor chassis 10 houses a conventional engine 12 serving to provide operational power for the tractor T and an operator's cab 13 positioned in an elevated location. The operator's cab 13 includes a steering wheel 14, positioned forwardly of the conventional operator's seat (not shown), to operate the steering of the front wheels 11 in a known manner. The chassis 10 is supported above the ground G in a conventional manner by forward steerable wheels 11 and rearward drive wheels 16 rotatably mounted in a customary transversely spaced orientation.
The hood 20 is mounted on the chassis 10 forwardly of the operator's cab 13 to enclose the engine 12. The hood 20 is pivotally mounted by a hinge mechanism 30 defining a generally horizontal, transverse hinge axis 39 positioned next to the operator's cab 13 to enable the hood to move upward and rearwardly toward the operator's cab 13. Gas springs 24 detachably connected to mounting brackets 25 affixed to the chassis subframe 15 interconnect the chassis 10 and the hood 20 to counterbalance a major portion of the weight of the hood to facilitate the manual lifting of the hood 20 in a manner described in greater detail below.
A latching mechanism 40 retains the hood 20 in its closed position completely enclosing the engine 12. The chassis subframe 15 is supported on the engine block 12a, which in turn is supported from the chassis 10, to provide support for the various mounting components as described in greater detail below. A slide mechanism 50 limits the opening of the hood from the closed position and defines an intermediate opened position from which most of the routine servicing of the engine 12 can be accomplished, as will also be described in greater detail below.
As best seen in FIGS. 3-7, the hinge mechanism 30 includes a hinge support 32 having a lower portion 33 detachably affixed to the engine block 12a and to the chassis subframe member 15 by fasteners. The hinge support 32 also has an upper portion 34 pivotally attached to the lower portion 33 by a generally vertically extending central pivot pin 35 and by a pair of opposing lateral fasteners 36 extending through respective slotted openings 37 in the lower portion 33 to clamp the upper and lower portions 33, 34 together, yet provide a limited range of relative pivotal movement therebetween about the central pivot pin 35. The upper portion 34 also carries a pair of laterally disposed hinge pins 38 to provide a generally horizontally disposed hinge axis 39 for the one piece hood 20.
The pivotal movement of the upper portion 34 of the hinge support 32 relative to the lower portion 33 provides a side-to-side adjustment of the hood 20, as depicted in phantom in FIG. 4, to permit the orientation of the hood 20 to be matched to the chassis 10 for proper enclosure of the engine 12. By loosening the lateral fasteners 36, the upper portion 34 can be pivoted about the central pivot pin 35, which in turn rotates the hinge axis 39, to which the hood 20 is attached, about the central pivot pin 35. The slotted openings 37 provide a limited range of pivotal movement of the upper portion 34. A re-tightening of the lateral fasteners 36 locks the upper portion 34 against the lower portion 33 to fix the orientation of the hood 20 relative to the chassis 10.
The hood 20 has a contoured surface to provide a pleasing aesthetic appearance. The top portion 27 of the hood 20 is manufactured preferably from a polymer such as fiberglass reinforced polyester with directed fiber preform by a process called liquid composite molding, which provides a high gloss finish, but does not permit the incorporation of mounting bosses. The thickness of the material is approximately 4 millimeters. The side panels 28 are also preferably manufactured from fiberglass reinforced polyester by a manufacturing process called sheet molding compound, which allow for the incorporation of mounting bosses. The side panels 28 are bonded to the top portion 27 by high tech, heat cured adhesives. As a result, the hood 20 can be pre-formed from polymer material with a relatively uniform thickness to provide a low cost hood with satisfactory strength characteristics and a high gloss exterior finish.
A hinge casting 31, preferably constructed of aluminum so that the thermal expansion of the hinge casting 31 is similar to that of the polymer hood 20, is formed with the same contoured shape as the interior surface of the top portion 27 of the hood 20 to which the hinge casting 31 is to be attached. The hinge casting 31 is bonded to the underside of the hood 20 with the same heat cured adhesives to form a permanent bond with the hood 20. The hinge casting 31 is then connected to the hinge support 32 to pivotally mount the hood 20 to the chassis 10 for movement about the rearwardly located hinge axis 39.
Referring to FIGS. 3, 4 and 7, one skilled in the art will see that the latching mechanism 40 includes a centrally positioned latch pin 42 attached to a central hood support 43 bonded to the interior surface of the top portion 27 of the hood 20 in substantially the same manner as the hinge casting 31. The releasable clasp 45 is supported from the chassis subframe 15 at a position to engage with the latch pin 42 when the hood 20 is moved to a closed position. A latch release linkage 46 includes a pivoted handle 47 positioned for convenient access by the operator and a connecting link 48 interconnecting the handle 47 and the releasable clasp 45 to transfer the pivoted motion of the handle 47 to the clasp 45 to effect actuation thereof in a conventional manner. One skilled in the art will recognize that the latch release linkage can also be formed as an equivalent cable release.
Referring now to the views of FIGS. 3, 4 and 7-11, the mechanism 24, 50 for controlling the pivotal movement of the hood 20 can best be seen. The raising of the hood 20 is assisted by gas springs 24 positioned on opposing sides of the hood 20. The nitrogen gas filled springs 24 provide a lifting force to offset the weight of a major portion of the hood 20 and attached components, such as the hinge casting 31 and the central hood support 43. As a result, the hood 20 is easier to lift manually when the latch pin 42 is released from the clasp 45. Since the nitrogen gas tends to escape from the springs 24 over a period of time, thereby causing the gas springs to weaken and lose spring force, it is undesirable that the overall counterbalance effect of the gas springs be lost.
Accordingly, the gas springs 24 are oriented between the central hood support 43 and the mounting brackets 25 affixed to the chassis subframe 15. The mounting brackets 25 are formed with at least two mounting holes 26 that are generally aligned with the hinge axis 39 such that mounting hole 26a is closer to the hinge axis 39 than mounting hole 26b. The lifting force of the gas springs 24 about the hinge axis 39 is a product of the spring force of the gas springs multiplied by the linear distance (M1, as depicted in FIGS. 10 and 11) between the mounting hole 26 to which the gas springs 24 are connected and the hinge axis 39.
By re-mounting the gas springs 24 at the alternate mounting hole 26b, the distance M2 between the mounting hole 26b and the hinge axis 39 is greater than the distance M1. As a result, the lifting force of the gas springs 24 can be maintained substantially constant as the spring force lessens by increasing the moment arm M1, M2 through which the spring force acts. One skilled in the art will realize that more than two mounting holes 26 can be provided to give yet a greater range of adjustment of the lifting force of the gas springs 24.
Because of the overall size of the hood 20, the amount of pivotal movement of the hood 20 about the hinge axis 39 required to fully expose the engine 12 to access by the operator is quite substantial. While a fully opened hood 20 is necessary for some maintenance or repair of the engine 12, normal daily maintenance generally requires only a partial opening of the hood 20 to an intermediate opened position. Pivotal movement of the hood 20 to an intermediate opened position also minimizes the exposure of the hood 20 to the wind or other external forces.
A slide mechanism 50 is provided to limit the movement of the hood 20 to an intermediate opened position unless manually manipulated to allow further pivotal movement of the hood 20 to the fully opened position. The slide mechanism 50 includes a slide pin 52 mounted to the chassis subframe 15 and extending generally horizontally outwardly therefrom. A slide member 55 is pivotally connected to the central hood support 43 so as to be movable with the hood 20 about the hinge axis 39. The slide member 55 has a bayonet slot 56 formed therein from a first opening 57 and a generally parallel second opening 58 interconnected by a passageway 59 extending perpendicularly thereto to form a continuous, two-part bayonet slot 56. The slide pin 52 is positioned within the bayonet slot 56 for slidable movement therein while the hood 20 pivotally moves about the hinge axis 39.
Due to the configuration of the bayonet slot 56, the slide pin 52 stays within the first opening 57 when the hood is moving between the closed position and the intermediate opened position, as depicted in FIG. 8, the force of gravity keeping the slide member 55 resting against the slide pin 52 so that the slide pin 52 bottoms out against the end of the first opening when the hood reaches the intermediate opened position. To permit the hood to open beyond the intermediate opened position to the fully opened position, the slide member 55 must be manually lifted to allow the slide pin 52 to pass along the passageway 59 interconnecting the first and second openings 57, 58 and enter the second opening 58. The slide pin 52 can then move within the second opening 58 as the hood 20 pivotally moves to the fully opened position. The distal end of the second opening 58 is enlarged to allow the slide member 55 to fall by gravity when the hood 20 reaches the fully opened position and thereby restrain the hood 20 in the fully opened position until manually moved to allow the slide pin 52 to move within the second opening 58.
A hood 20 constructed as described above can be manufactured with relatively low cost tooling in a cost effective manner. The hood is supported on three points, the two laterally spaced rearward hinge pins 38 and the latch pin 42, which simplifies adjustment and reduces complexity. The slide mechanism 50 controls the opening height of the hood 20 and also serves as a safety catch in the event of a failure of a gas spring 24 if the hood 20 is moved beyond the intermediate opened position. The hinge components 31, 32 provide accurate adjustment of the hood 20 relative to the chassis 10 and can be integrated into the hood structure to provide strength and cost effectiveness.
It will be understood that changes in the details, materials, steps and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown. | A pivotally mounted hood for a tractor is disclosed wherein a gas spring, provided to offset the weight of the hood to facilitate the movement of the hood between opened and closed positions, is mounted to the chassis via a multi-position bracket having more than one hole therein for the selective connection of the gas spring. The bracket holes are arranged in a configuration defining a progressively increasing distance from the pivot connecting the hood to the chassis, thereby providing alternative mounting positions for the gas spring which have different moment arms for the application of the force exerted by the gas spring about the hood pivot. The gas spring can be remounted to a hole providing a larger moment arm relative to the hood pivot as the gas spring weakens over time due to the loss of gas therefrom, which enables the effective spring force offsetting at least a portion of the weight of the hood to remain substantially constant even though the gas spring weakens. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 61/304,228, “METHODS OF MANUFACTURING AND TEMPERATURE CALIBRATING A CORIOLIS MASS FLOW RATE SENSOR” by Alan M. Young, Jianren Lin, and Claus W. Knudsen, filed on Feb. 12, 2010, the content of which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates generally to fluid mass flow rate and density measuring apparatus based on the Coriolis-effect and in particular, methods for fabricating and calibrating an improved Coriolis flow rate sensor constructed from an elastic polymeric material (e.g., PFA—perfluoroalkoxy copolymer).
DESCRIPTION OF PRIOR ART
It is well known that Coriolis mass flowmeters can be used to measure the mass flow rate (as well as other properties) of a fluid flowing through a pipeline. Traditional Coriolis flowmeters employ various configurations of one or two tubes that are oscillated in a controlled manner allowing measurement of Coriolis induced deflections (or the effects of such deflections on the tube(s)) as an indication of fluid mass flow rate flowing through the sensor. As expressed in U.S. Pat. No. 7,127,815 B2 (col. 2, lines 5-25), much of the Coriolis flowmeter prior art is concerned with using metal flow tubes as the flow-sensitive element, but the prior art also suggests that plastic may be substituted for metal. The '815 patent states that “the mere assertion that a flowmeter could be made out of plastic is nothing more than the abstraction that plastic can be substituted for metal. It does not teach how a plastic flowmeter can be manufactured to generate accurate information over a useful range of operating conditions.” Similar statements are found in U.S. Pat. No. 6,776,053 B2 (Col. 1, lines 58-68 and Col. 2, lines 1-10).
The '815 and '053 patents describe methods of fabricating a Coriolis flowmeter with at least one PFA tube attached to a metal base using a cyanoacrylate adhesive. Fundamental to the successful operation of any Coriolis flowmeter is that the flow sensitive element (e.g., a tube in the '815 and '053 patents) must be fixedly attached to a metal base (or manifold) in such a manner that a fixed, stable and unchanging boundary condition is established for the ends of the vibrating sensitive element. For example, the '053 patent states in claim 1 (Col. 14, lines 65-67) that “ . . . end portions of said flow tube apparatus coupled to said base to create stationary nodes at said end portions . . . ”. However, a shortcoming of the '053 and '815 patents is that under normal operating conditions the integrity of the coupling of the tube to the metal base is not necessarily unyielding and unchanging. Rather, it could deteriorate over time from continuous vibration of the tube causing the adhesive joint to crack or otherwise degrade. Additionally, differential thermal expansion/contraction between the different materials of construction (e.g., the tube, the cyanoacrylate adhesive and the metal base) will impair the integrity of the coupling of the tube to the metal base creating an unstable boundary condition resulting in uncontrolled vibration characteristics to such an extent that performance of the device would be compromised.
The '815 and '053 patents describe properties of PFA tubing which, by its method of manufacture (i.e., extrusion) inherently has bends or curvature that must be eliminated prior to manufacturing a flowmeter (e.g., see '815, Col. 3, lines 42-55). According to the '815 and '053 patents, this problem can be alleviated by subjecting the PFA tubing to an annealing process (see '815, col. 3, lines 30-41) in order to straighten the tube prior to fabricating a flowmeter.
To facilitate binding of the cyanoacrylate adhesive to the PFA tube, the tubing must be subjected to etching (a process referred to in the '815 patent) that requires submersing and gently agitating PFA tubes in a heated bath containing glycol diether. However, these annealing and etching processes add cost and complexity to the fabrication of the flowmeter and may not necessarily yield tubing suitable for flowmeter fabrication on a consistent basis.
U.S. Pat. No. 6,450,042 B1, U.S. Pat. No. 6,904,667 B2 and US Patent Application Publication No. 20020139199 A1 describe methods of fabricating a Coriolis flowmeter via injection molding and forming the flow path from a core mold made from a low-melting point fusible metal alloy containing a mixture of Bismuth, Lead, Tin, Cadmium, and Indium with a melting point of about 47 degrees Celsius. The '042 patent asserts (Col. 2, lines 65-67) that “ . . . with the possible exception of a driver and pick offs, and case, the entirety of the flowmeter is formed by injection molding (emphasis added).” However, this method of fabrication presents significant problems and limitations. During the injection molding process, hot plastic is injected into a mold at temperatures that can exceed 350 degrees Celsius at pressures exceeding 5000 psi. When fabricating thin-wall or small diameter flow passageways (e.g., 4 mm diameter; wall thickness <2 mm) such melt temperatures and pressures will likely distort the comparatively narrow (and flexible) fusible metal core (possibly melting its surface) resulting in deformation and contamination of the flow passageways to such an extent that the device could be rendered unusable. In semiconductor, pharmaceutical, bio-pharmaceutical (or other critical high-purity process applications) it is important to avoid metallic contamination however infinitesimal. However, unlike a solid core (e.g., stainless steel), the comparatively soft fusible core could partially melt or abrade during the injection molding process allowing metal atoms to mix and become embedded within the injected plastic permanently contaminating the flow passageway rendering the device unsuitable for high-purity applications.
In plastic injection molding processes, it is generally recommended that molded features have a similar thickness because otherwise the molded part may not form properly. With reference to the '042 patent, this requirement means that all structural features of the Coriolis flowmeters described therein, namely the tube wall, “brace bars”, inlet and outlet flanges, manifold walls, . . . etc., must all have a similar thickness. However, a consequence of forming the entirety of the flowmeter by injection molding could result in structural and/or dynamic design limitations or compromises that could adversely affect and/or limit flowmeter performance.
The “spring constant” of a tube material (which is proportional to Youngs Modulus) varies with temperature and directly affects the accuracy of a Coriolis flowmeter. To maintain flow rate measurement accuracy, Coriolis flowmeters require temperature compensation as the fluid and/or ambient temperature changes the temperature of the flow-sensitive element. Youngs Modulus data vs. temperature is available from N.I.S.T. (or other technical references) for most all metal alloys used in the construction of prior art Coriolis flowmeters (e.g., stainless steel or Titanium). However, comparable data (e.g., elastic modulus vs. temperature) for elastic polymers are generally not available or are published at very few temperatures. Hence, prior art suggesting or describing the use of plastic for fabricating a Coriolis flowmeter, which also mention means for sensing the temperature of the flow-sensitive element (e.g., see '815, col. 4, lines 59-67), fail to describe how to implement effective temperature compensation over a range of operating temperatures for any given elastic polymeric material. Significantly, without such temperature compensation, the meter would not be usable in applications wherein the sensor temperature differs substantially from that at calibration.
SUMMARY OF THE PRESENT INVENTION
It is an aspect of the present invention to provide a method of fabricating a Coriolis flowmeter from an elastic polymeric material having flow sensitive element(s) integrally connected to a suitable mounting base (or manifold) of the same material free of mechanical joints or adhesives thereby providing an unyielding, fixed boundary condition for the vibrating sensitive element.
It is another aspect of the present invention to provide a method of fabricating a Coriolis flowmeter from an elastic polymeric material having a flow sensitive element integrally connected to a suitable mounting base (or manifold) of the same material free of adhesives or mechanical joints thereby avoiding differential thermal expansion/contraction that would otherwise undermine the integrity and reliability of the boundary condition at the ends of the vibrating flow sensitive element.
It is another aspect of the present invention to provide a method of fabricating a Coriolis flowmeter from an elastic polymeric material employing a flow sensitive element that does not use tubing thereby avoiding the additional processing steps such as annealing and etching thereby simplifying the flowmeter fabrication process.
It is another aspect of the present invention to provide a method of fabricating a Coriolis flowmeter from an elastic polymeric material and forming a flow sensitive element (and flow passageways therein) without using low-melting point fusible metal alloys that could permanently contaminate the flow passageway(s).
It is another aspect of the present invention to provide a method of fabricating a Coriolis flowmeter from an elastic polymeric material allowing the fabrication of a flow sensitive element with comparatively thin-walls and/or with relatively small diameter flow passageways therein.
It is yet another aspect object of the present invention to provide a method for calibrating a Coriolis flowmeter fabricated from any elastic material (metal or plastic) allowing for accurate temperature compensation of the flow sensitive element's spring constant over any useful operating temperature range of the flowmeter.
Briefly, an embodiment of the present invention includes a structure employing a flow-sensitive element comprising two substantially identical members wherein each member is shaped in the form of a rectangular “U” (or a triangle among other possible shapes that may be fabricated from straight sections) which extend from a support to which they are integrally connected. Fluid flows through each member of the flow-sensitive element in a hydraulically serial (or parallel) fashion via suitable external fluid connections. The “legs” of the flow sensitive members may have circular, oval, rectangular, hexagonal, or octagonal cross-section. The structure is fabricated from a single piece of elastic polymeric material. The fabrication process involves either CNC (computer numerical control) machining the entire structure from a single piece of polymeric material and drilling the flow passageways as a secondary operation. Alternatively, the structure can be fabricated by injection molding, the flow passageways being formed by a combination of a solid core employed within the mold and/or secondary drilling operations after the part is removed from its mold. These fabrication methods yield a completely functioning (i.e., dynamically responsive) flowmeter after secondary (post-molding) operations. External holes (from coring or drilling) are filled by a suitable secondary procedure (e.g., welding).
These and other objects and advantages of the present invention will no doubt become apparent to those skilled in the art after having read the following detailed description of the various embodiments illustrated in the figures of the drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 . Illustration of a partially constructed Coriolis flow sensor subassembly fabricated from an elastic polymeric material without internal flow passageways.
FIG. 2 . Illustration of a partially constructed Coriolis flow sensor subassembly fabricated from an elastic polymeric material with internal flow passageways formed by drilling.
FIG. 3 . Illustration of a partially constructed Coriolis flow sensor subassembly fabricated from an elastic polymeric material with sealed drill-holes for internal flow passageways.
FIG. 4 . Illustration of a partially assembled Coriolis flow sensor with excitation magnet-coil assembly and motion-sensing magnet/coil assemblies.
FIG. 5 . Illustration of a partially assembled Coriolis flow sensor fabricated from an elastic polymeric material connected to metering electronics.
FIG. 6 . Frequency vs. temperature data obtained from a Coriolis flow sensor fabricated from PFA.
FIG. 7 . Illustration of temperature sensing means bonded to the elastic polymeric material.
FIG. 8 . Illustration of additional embodiments of flow-sensitive elements.
DETAILED DESCRIPTION
The Figures (FIGS.) and the following description describe certain embodiments by way of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles described herein. Reference will now be made in detail to several embodiments, examples of which are illustrated in the accompanying figures. It is noted that wherever practicable similar or like reference numbers may be used in the figures and may indicate similar or like functionality.
FIG. 1 illustrates a solid piece 110 of polymeric material, CNC-machined from a single block of elastic polymeric material, according to one embodiment. The flow-sensitive element of subassembly 110 is comprised of two square “U”-shaped assemblies 120 and 130 . However, subassembly 110 is devoid of flow passageways to allow fluid to flow through the structure. Sub-assembly 110 can also be formed by injection molding but, as with the CNC-machined version, without any provision for flow passageways. By the very nature of how structure 110 is fabricated (i.e., CNC machining or injection molding), each “U” is integrally connected to “isolation plates” 175 , 180 and 185 , 190 (which establish boundary conditions for vibration of the “U”-shaped structures 120 and 130 ) and, in turn, is integrally connected to support 155 . Importantly, subassembly 110 is fabricated as one solid part devoid of mechanical joints, adhesives or without using any metal support.
FIG. 2 illustrates sub-assembly 210 , but with flow passageways 240 and 260 drilled completely end-to-end laterally along the centerline of the “end-section” of each “U”, according to one embodiment. Likewise, flow passageways 245 , 250 , 265 and 270 are drilled completely through along the centerline of the side-legs of each “U” and through to exit the rearmost end of support 255 (not shown). Additionally, according to one embodiment, to complete fabrication of flow channels through each “U”, the drilled openings are sealed as illustrated in FIG. 3 wherein each hole at the end “U” is sealed by welding or by melting plastic into the drilled entrances of passageways 340 , 345 , 350 and 360 , 365 , 370 . According to one embodiment, to prevent blockage of the flow passageways during the sealing or welding operation, a mandrel with a rounded-tip is inserted along the length of each passageway prior to sealing holes allowing the plastic melt to form a smooth surface against the rounded tip of the mandrel thereby preventing internal blockage of the flow passageway. Plumbing connections (not shown) configured at the rear of block 355 allow fluid to flow through each “U” in a hydraulically serial or parallel manner.
Members of the flow-sensitive element are not limited to the square “U”-shape shown in FIGS. 1 and 2 , and can have other shapes that may be fabricated from straight sections. FIG. 8 illustrates four example shapes for the flow-sensitive element members: triangle (options (A) and (E)), square (option (B)), trapezoid (option (C)), and straight line (option (D)).
FIG. 4 depicts a subassembly 410 of a Coriolis flowmeter having a pair of sensitive elements 420 and 430 integrally attached to support block 455 , according to one embodiment. Fluid material is introduced at the rear of block 455 and is directed to flow in the same direction through each flow sensitive element 420 and 430 in a hydraulically serial or parallel (i.e., split flow) manner. Flow sensitive structures 420 and 430 extend through isolation plates 475 , 480 , 485 , 490 to support block 455 . Support block 455 , flow sensitive structures 420 and 430 and isolation plates 475 , 480 , 485 , 490 are integrally connected as they are all fabricated from a single monolithic piece of elastic polymeric material.
FIG. 4 discloses a magnet and coil “driver” comprised of permanent magnet 492 and coil 494 fixedly attached respectively to flow sensitive elements 420 and 430 , which are caused to vibrate in phase opposition similar to the tines of a tuning fork. FIG. 5 illustrates driver coil 510 is energized by signals received from meter electronics 522 over path 524 . The material flow through the vibrating flow tubes generate Coriolis forces which are detected by magnet/coil inductive “pick-offs” (or “velocity sensors”) located on opposite sides of flow sensitive structures 520 and 530 . These sensors generate signals responsive to the motion generated in the side legs of flow sensitive structure 520 and 530 due to flow-induced Coriolis forces. The output signals of these magnet/coil inductive sensors are transmitted over paths 526 and 528 to meter electronics 522 which processes these signals and applies output information over path 529 indicative of the fluid material flow rate.
The vibration of elements 520 and 530 in phase opposition at their natural frequency is analogous to the vibrating tines of a tuning fork and can be modeled as a damped second-order system. Neglecting dampening, the resonant frequency in the excitation (or “drive”) mode wherein elements 520 and 530 are oscillated in phase opposition, ω d is expressed as:
ω d =√( k d /m ), (1)
where the natural circular frequency ω d =2πf d , f d =natural frequency in cycles/second and m=m element +M fluid and the spring constant k d is proportional to the elastic modulus of the material in the “drive” or excitation mode. The terms m element and m fluid respectively represent the effective mass of the element 520 (or 530 ) and the mass of the fluid contained therein. For metal alloys (e.g., 316L stainless steel) the elastic modulus and it's variation with temperature is well-documented. However, such is not the case with elastic polymers. The variation of spring constant, k, which is necessary to properly compensate for the temperature variation of the spring constant of an elastic polymeric material with vibrating sensitive elements 520 and 530 , is not documented. In particular, the elastic modulus that requires compensation is that corresponding to the twist (torsion) or Coriolis mode, k c . However, from Equation (1), it can be seen that
k d =mω d 2 , (2)
and in the twist (torsion) or “Coriolis” response mode,
k c =mω c 2 , (3)
wherein k c is the shear modulus of the elastic polymer and can be related to k d by the Lame′ constant μ as expressed in the following equation:
k c =k d /2(1+μ)= mω d 2 /2(1+μ). (4)
Thus, measuring the variation of ω d 2 with temperature allows one to measure a quantity proportional to the variation of the material's shear modulus (i.e., the material's elastic modulus in the response or Coriolis mode) over a given temperature range as illustrated in FIG. 6 . This consideration applies to not only elastic polymers, but any suitable elastic material including metal, ceramic, and glass materials.
With reference to FIG. 7 , temperature sensing means 742 is bonded to the polymeric material and communicates the temperature of the polymeric material over path 744 to meter electronics 722 , according to one embodiment. Meter electronics 722 contains information proportional to ω d 2 versus temperature thereby allowing the meter electronics to material's shear modulus) with temperature that (in combination with other factors) is a proportional factor that relates the measured signals to the fluid mass flow rate flowing through the device.
Coriolis flowmeters exhibit a flow rate indication even though no fluid is flowing through the meter. This indication is referred to as the “zero flow offset” or “Z.F.O.”. One of the contributor's to Z.F.O. is a structural and/or mass imbalance from left to right causing the “U” structures to twist relative to one another as if fluid were flowing through the device. FIG. 4 illustrates two adjustment screws 495 and 496 that allow independent manual adjustment of the sensor's moment of inertia of each flow sensitive element 420 and 430 in the sensor's response mode as required in order to minimize the magnitude of the Z.F.O. with a simple screwdriver adjustment.
A mass or structural imbalance between the two “U” structures may cause the Q-factor of the oscillating structure to be lower (i.e., the “tuning fork structure” comprised of 420 and 430 may not be balanced), thereby forcing the meter electronics to deliver more energy to maintain sufficient amplitude of oscillation in order to keep the sensor's measurement sensitivity within acceptable levels. To adjust the imbalance between the two “U” structures ( 420 and 430 ), in one embodiment threaded rods with attached weights (or “nuts”) 497 and 498 are added as a simple mean of adjustment to better balance the sensor's sensitive elements ( 420 and 430 ) akin to balancing the tines of tuning fork. | A subassembly of a Coriolis flowmeter is fabricated from a single monolithic piece of elastic polymeric material. The subassembly includes two flow-sensitive members and a base integrally connected to the two flow-sensitive members. The two flow-sensitive members include straight sections, and are substantially similar and parallel to each other. Flow passages are drilled along the straight sections of the two flow-sensitive members, and drilled entrances are sealed using the elastic polymeric material. A temperature sensor is fixedly attached to a flow-sensitive member for measuring a temperature of the flow-sensitive member and communicating the temperature to a metering electronics. The metering electronics determines a calibrated flow rate of fluid flowing through the Coriolis flowmeter that accounts for the temperature. | 8 |
FIELD OF THE INVENTION
The illustrative embodiment of the present invention relates generally to process visualization and more particularly to performing three dimensional graphical visualization of multi-dimensional batch process data including analysis and visualization prior to process completion.
BACKGROUND
Process engineers overseeing manufacturing processes analyze collected data related to the manufacturing process to detect faults and monitor conditions associated with the process. The analysis may be performed dynamically in conjunction with an ongoing process, or it may performed “off line” in an effort to improve the process for the next performance. Technological advances in the form of more sophisticated statistical analysis programs, faster computers and advanced process databases have contributed to increased efforts in this area by process engineers.
There has also been considerable and growing interest among researchers and practitioners in the application of process monitoring to batch processes. Batch processes typically display a non-steady state during processing. Economically the growth in interest in process monitoring this has been driven by the value of early detection and diagnosis of batch process disturbances (since many batch processes often involve high value products which in many cases have to be discarded if the batch does not follow an ‘in control’ trajectory). One source of the growing interest has been the lack of on-line critical product quality measurements for many batch processes. The inability to produce product quality on line measurements has sharpened the need for technology which can use existing indirect measurements of product quality to provide warning of deviant process conditions during the execution of the batch, while there is still time to take a mid-course correction.
The most widespread and established application of process visualization technology has been in its most basic form, where process operators view electronic versions of Statistical Process Control (or SPC) charts for a selection of measured process variables. Anomalous or upset process conditions are detected by recognizing when the time series shown on those charts deviate from some defined control region. The simplicity of the SPC approach has contributed to its popularity, but there are two major practical drawbacks that have limited its effectiveness:
In most manufacturing processes the measured variables are related to each other through physical interaction, so that there is not necessarily a direct relationship between a particular variable exiting its control limits and the root cause of a process upset. Additionally, most manufacturing operations have hundreds or more measured variables, making it impossible for a human operator to monitor each and every measurement using a separate SPC chart.
These limitations regarding SPC charts have prompted the development of other approaches to process condition monitoring based on Principle Component Analysis (PCA) and Partial Least Squares (PLS) as well as other multivariate statistical methods. These alternative techniques essentially detect the existence of a process upset by monitoring certain common factors (subsequently referred to herein as ‘scores’), chosen to represent significant components of the overall process variability. An upset condition is flagged when the vector of scores exits some defined control region subsequently labeled the ‘in-control’ and ‘control’ region. There are established mathematical methods for detecting the incidence of this type of ‘out of control’ event, but visualization of the behavior of the scores relative to the ‘in control’ region can offer physical insight into the process behavior and the cause of an upset, especially in cases where the scores are imbued with some physical meaning. Conventionally, two approaches are used to perform visualization of the behavior of scores relative to control regions whenever 3 or more scores are involved:
Each scalar score component is viewed separately from the other scores but relative to the limits of the ‘in control’ region as they apply that component. The resulting monitoring display consists of n SPC strip charts (where n is the number of score components). Conceptually this is the equivalent of plotting a one dimensional cross-section of an n-dimensional score space viewed relative to upper and lower bounds defined by a one dimensional cross-section of the n-dimensional solid that defines the ‘in control’ region. In cases where the process condition is represented by 3 scores, a graphical projection method is often used to provide a 2 dimensional depiction of the scores and the 3 dimensional solid representing the control region (usually an ellipsoid). Those skilled in the art will recognize that 2 or fewer scores can be monitored with a two dimensional planar plot of the score trajectories and ‘in-control’ region without requiring any of the visualization features described in this disclosure.
One drawback of the first approach (where each coordinate is viewed separately) is that it ignores the real dependence of the ‘in-control’ boundaries on a combination of the coordinates, making it difficult to assess the in-control state of the process without considering all the score values simultaneously. A consequence of ignoring the effect of combining coordinates is that separate strip plots of each score can disguise the severity of an impending process upset. FIG. 1A shows a graphical projection 1 of a sequence of three scores representing the state of a monitored process where the coordinates have already been combined. The evolution of the score trajectory is represented by a line 2 and the coordinates of the most recent 3 scores are indicated by a dot 4 (it should be understood throughout the discussion herein that many of the described visualization techniques are performed using colors on an electronic display to increase visual contrast). The translucent semi-ellipsoid represents the bottom half of the ‘in control’ region enclosing score values defined by normal operation. It is apparent from the graphical projection 1 that the trend is towards an imminent exit of the score plot control region, and impending detection of a process upset. However, the corresponding strip chart plots 8 , 10 and 12 of the individual scores and their individual control regions are shown in FIG. 1B (each individual control region is defined by the values of that coordinate within the ellipsoidal control region shown in FIG. 1 b .) The individual strip charts 8 , 10 and 12 give no indication of the impending upset since each score trajectory is well within the interior of each ‘in control’ band.
It should be noted that the concept of scores as defined in PCA/PLS process monitoring (as the coefficients describing the state of the process in the subspace of principle components) can be extended to any application where the process condition is summarized by a numerical vector. Other examples, which are based on physical rather than statistical process models, might include applications where the process condition is represented by estimates of physical quantities such as stored heat, new inflow, heat flux, etc.
In cases where the scores may be associated with physical quantities relating to process operation, the relative position of the score trajectory and the ‘in-control’ region provides an indication of what corrective action is needed to bring the process back into control. While strip chart plots such as those shown in FIG. 1B indicate the relative adjustments of each score required to move the process back into the ‘in-control’ region, the geometrical intuition provided by graphical projections usually provides faster human perception of the relative adjustments of the three score values. The graphical projection approach has therefore increasingly been used to try to give a more geometrical view of the scores and the ‘in control’ region. In general however even this is not sufficient to completely convey either the process state or its trend.
Although more informative than the strip charts, a static graphical projection suffers from a number of drawbacks. Conventional graphical projections cannot unambiguously convey the position of the scores in a 3-dimensional space since the computer screen is essentially a 2-dimensional depiction and each point on a graphical projection defines a line in 3 dimensions. The user must also be able to move the viewpoint of the display in order to create a sequence of graphical projections so as to clarify the ambiguity of multiple positions in 3 dimensional space corresponding to a single point depiction on a 2 dimensional graphical projection. The ability to shift viewpoint in order to view processed data is missing in conventional methods. Additionally, the representation of the control region fails to allow viewing of both the interior and exterior of the ‘in control’ region in order to display whether and where score trajectories enter or exit. Another significant shortcoming of conventional process visualization methods is that there are generally more than three scores, in which case a 3 dimensional graphical projection will not capable of representing the 4 or more score coordinates. Conventional process visualization techniques lack the ability to combine graphical methods with exploration methods in order to allow the user to vary the geometry of the projection and so gain insight into the relationship between the scores and the ‘in control’ region.
An additional problem with conventional graphical visualization methods arises when there is a need to visualize regions of scores represented as 3 dimensional or higher bodies (or geometrical shapes) as opposed to the type of score trajectories shown in FIG. 1A and FIG. 1B . The need to visualize three dimensional or higher bodies with a three dimensional control region arises in batch multi-way process monitoring where the scores are not known precisely during the batch and consequently score vectors are characterized as regions of uncertainty rather than single points. Also, ‘what if’ or scenario analysis analyses where measured variables are allowed to take values over some set of possibilities, and the potential interaction of the score loci with the ‘in control’ boundary must be viewed to asses the affect of each of the possibilities also requires the need to visualize the interaction of three dimensional or larger solids in space. In these situations inference depends on assessing the overlap of 3 dimensional or larger solids in space. Without the ability to vary the viewpoint parallax makes the process of determining the relative positions of the solids difficult and one dimensional cross sections often yield misleading results.
Unlike continuous processes, batch processes are usually designed to have varying conditions over the course of their run, and consequently any assessment of the batch condition must take into account the entire course history rather than just the current conditions. The standard approach to batch process monitoring is to use extensions of multivariate statistical methods for continuous processes (known as multi-way PCA and multi-way PLS) adapted to handle non-steady state conditions. Multi-way methods work by considering each new observation of each measured variable during the batch as a distinct variable, and the entire batch as a single observation of that collection of variables. Thus, the history of all the measured variables during the batch is reduced to a single vector representing one extended observation, and the overall batch state of the batch by the vector of scores calculated for that observation. Viewing observations of the same measurement at different times as distinct variables allows multi-way methods to treat different times differently, in effect recognizing that different periods of the batch trajectory are more or less impact on final product quality. However, computation of the score vector requires the complete batch history, which presents a challenge for in-course assessment of the state of the batch, because the observation set required for estimation of scores is not complete while the batch is running. Consequently, forecasts of future measurements are employed (extending from the current time until the end of the batch) to complete the multi-way observation vector and calculate estimates of the likely end of batch score vector. Since the future measurement trajectories are uncertain, the calculated end point scores are no longer defined by a vector but rather by a probability distribution.
When these probability distributions are viewed geometrically they define a region of probable values in score space rather than a single point. Assessment of whether the final score vector will likely end up in the control region then amounts to judging whether there is significant overlap between the region of end point uncertainty and the region defining the score values of ‘in-control’ batches. While probability distributions of score vectors for in-process batches have been derived by various methods in the research literature, there has been no development of techniques for their visualization other than for one score component at a time. Thus the potential for misleading and confusing results stemming from one-dimensional visualization that was discussed above is further heightened for the case of batch process monitoring attempting the more complex task of assessing the relative position of two regions (score uncertainty region which is evolving in time as more of the measurement trajectories become available and the ‘in-control’ region).
SUMMARY OF THE INVENTION
The illustrative embodiment of the present invention provides a method for forecasting batch end conditions through their depiction as a multi-dimensional regions of uncertainty. A visualization of the current condition of a continuous process and visualization of the simulated effect of user control moves are generated for a user. Volume visualization tools for viewing and querying intersecting solids in 3-dimensional space are utilized to perform the process visualization. Interactive tools for slicing multi-dimensional (>3) regions and drawing superimposed projections in 3-D space are provided. Additionally, graphical manipulation of the views of process conditions is accomplished by changing the hypothetical future values of contributing variables online in order to provide users the ability to simulate the effect of proposed control actions. The illustrative embodiment of the present invention may also be utilized in combination with a graphical programming environment supporting the execution and simulation of block diagrams and correspondingly generated process data. The scores representing the process condition may depend on estimated physical quantities as well as representations of process variability.
In one embodiment, in a computing environment with a display for viewing by a user, a method collects batch process data from an ongoing process. The batch process data comprises measurements of the ongoing process. Analysis is performed on the collection of data while the process is ongoing. An indicator of process condition is determined based on the analysis. The indicator of process condition is based in part on predicted future data from the ongoing process and estimates of uncertainty of those forecasts, The indicator of process condition and the control region are displayed in a graphical projection depicting a three dimensional view to the user monitoring the process.
In another embodiment, in a computing environment having a user interfaced with a display monitoring the process, a method provides batch process data that is measurements of the process. Analysis is performed on the collection of data. An indicator of process condition is determined based on the analysis. The indicator of process condition is a region containing likely batch end point score locations for the measured data in the process. The indicator of process condition and a control region of acceptable variability are displayed in graphical projection depicting a three dimensional view to the user monitoring the process. The user is able to manipulate a plurality of three dimensional parameters associated with the display via a control. In an embodiment, in a computing environment having a display for viewing by a user, a method collects batch process data from an ongoing process. The batch process data includes n dimensions of scores, the scores being common factors chosen by a user to monitor significant components of overall process condition. An indicator of process condition is determined based on analysis of the n dimensions of scores. The indicator of process condition is based in part on predicted future data from the ongoing process. Three dimensions of scores are selected from the n dimensions of scores. The indicator of process condition is displayed as a region for the selected three dimensions of scores based on a value in the n−3 non-chosen dimensions of scores. A visual indicator representing an end point for the n−3 dimensions of data within the control region is displayed in a two dimensional view. The visual indicator is cross-referenced to the three dimensional display and the indicator of process condition. The method then adjusts the display of the visual indicator of process condition in response to user movements of the two dimensional visual indicator.
In a different embodiment, in a computing environment a system includes a collection of process data from an ongoing process. The system also includes means for analyzing the collected data. The analysis determines an indicator of process condition based in part on predicted future data from the ongoing process. The system also includes a display displaying the indicator of process condition and a control region of acceptable variability in three dimensions to a user monitoring said process.
In an embodiment, in a computing environment with a display for viewing by a user, a method collects process data from a continuous process. Analysis is performed on the collection of data. An indicator of process condition is determined based on the state of the continuous process. The indicator of process condition and a control region are displayed in a graphical projection depicting a three dimensional view to the user monitoring the process.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 A(prior art) depicts a prior art graphical projection method;
FIG. 1 B(prior art) depicts a prior art Statistical Process Control Charts;
FIG. 2 is a block diagram of an environment suitable for practicing the illustrative embodiment of the present invention;
FIG. 3 depicts a five component model selected from the first 20 components;
FIG. 4 depicts the mapping process for completed batches;
FIG. 5 is a flowchart of the sequence of steps followed by the illustrative embodiment of the present invention to display process condition for completed batch processes;
FIG. 6 depicts the display differences between forecasts for normal and faulty test batches;
FIG. 7A depicts an uncertain forecast made by the illustrative embodiment of the present invention;
FIG. 7B depicts an satisfactory forecast made by the illustrative embodiment of the present invention;
FIG. 7C depicts an fault forecast made by the illustrative embodiment of the present invention;
FIG. 8 is a flowchart of the sequence of steps followed by the illustrative embodiment of the present invention to display process condition for ongoing batch processes;
FIG. 9 depicts visual controls provided by the illustrative embodiment of the present invention;
FIG. 10 depicts a data panner utilized by the illustrative embodiment of the present invention;
FIG. 11 depicts the interrelationship between the data panner of the present invention and the three dimensional view of the process data;
FIG. 12 is a flowchart of the sequence of steps followed by the illustrative embodiment of the present invention to visualize more than three dimensions of scores;
FIG. 13 depicts a current forecast for a batch end point predicted by the illustrative embodiment of the present invention;
FIG. 14 depicts display controls used to manipulate a forecast end point; and
FIG. 15 depicts the unfolding of measurements into a single data vector.
DETAILED DESCRIPTION
The illustrative embodiment of the present invention enables interactive visualization of ongoing batch processes. Multiple dimensions of collected process data may be visualized in a three dimensional environment to determine whether a continuation of the ongoing process is likely to continue until the end within acceptable operational parameters. The process visualization methods of the present invention scale to handle more than three dimensions of data. Process engineers monitoring a process are able to alter variables in the displayed visualization in an attempt to determine acceptable changes to the ongoing process.
FIG. 2 depicts an environment suitable for practicing the illustrative embodiment of the present invention. A computing environment 13 such as a MATLAB™ and/or SIMULINK™ (from The MathWorks, Inc. of Natick, Mass.) based environment includes or has access to a statistical analysis package 14 . The computing environment is also interfaced with a source of collected process data 15 . The statistical analysis package 15 is used to analyze the collected process data by PCA, PLS or similar methods. The source of collected process data 15 is collecting, or has collected, data from a process 19 that may be ongoing and may be a continuous process. The process may be a manufacturing process such as the production of petrochemicals or semiconductors, or it may be another process that generates data such as the execution or simulation of a block diagram. A user 16 , who may be a process engineer, may monitor the process 19 while the process is ongoing. The user 16 is also interfaced with a display 17 which is connected to the computing environment 13 . A visualization package in the computing environment is used to display analyzed process data in three dimensional and two dimensional views on the display 17 for the user's review.
For the purpose of explaining the establishment of the control region used by the illustrative embodiment of the present invention, reference will be made herein to a sample batch monitoring of a semiconductor metal etching process. Data supporting the examples is available from Eigenvector Research at http://www.evriware.com/Data/Data_sets.html. This publicly available data set consists of the measurements of engineering variables from a LAM 9600 Metal Etcher over the course of etching 129 wafers. The data consists of 108 normal wafers taken during 3 experiments and 21 wafers with intentionally induced faults taken during the same experiments. For each wafer, about 100 measurements were taken for 21 variables during the process run.
Multi-way PCA procedures may be used to represent the state of each batch as a PCA score vector. Datasets from normal (calibration) batch runs are used in order to extract the lowest possible order principal component space that explains most of the process variability for a normal operation. The principal component model that explains most of the process variability is then used to define a nominal region of acceptable variability in the principal component space for the calibration batches. The test dataset is mapped to the reduced order principal component space in order to represent the entire history of the dataset as a single point in the score space.
As an example, for derivation of a PCA model, 107 normal batches were run. Twelve out of twenty-one variables were chosen for analysis. The measurements of these variables were interpolated to produce a uniform sampling interval and the entire measurement set of a batch was unfolded into a single data vector. The result was 107 vectors of nominal data (one for each batch), each containing about 1100 samples. Using PCA modeling technique, a five component model for the calibration data was extracted. As shown in FIG. 3 which shows the total variability for the first twenty components, the five component model 22 explains most of the process variability (for normal runs) and a three component model could also have been chosen.
Using the five component model 16 , it is possible to map the data vector of each normal (calibration) batch into the (5 dimensional) score space as a single point. The ellipsoid defined by the 95% variance of these points from the 107 normal batches is taken as the region of nominal (acceptable) variance. This region will be referred to as in-control region.
Once the in-control region has been defined, the unfolded data vectors for the test batches may be mapped onto the score space as single points and their location evaluated relative to the in-control region. FIG. 4 depicts the mapping process for completed batches. A control region 24 includes a mapped point 26 for a test batch inside the in-control region (dot in the figure). The location indicates with 95% confidence that the test batch was probably normal (good). The test point 28 that lies outside the in-control region 24 indicates that there is a strong likelihood that this particular test batch ran differently from a normal batch (dot outside control region). This may be an indication of a fault or failure to a process operator.
FIG. 5 depicts a flowchart of the sequence of steps followed by the illustrative embodiment of the present invention to display process condition for completed batch processes. The sequence begins by providing a collection of batch process data (step 30 ). An indicator of process condition is then determined quantifying the end point of the dataset as a vector of scores (step 32 ). A control region enclosing the acceptable variability in in-control batch scores is displayed (the control region having been determined in the manner discussed herein) in a three dimensional view (step 34 ). The indicator of process condition is then displayed on the same display as the control region (step 36 ). The user may then manipulate the display (as discussed herein) in order to determine the location of the indicator of process condition in reference to the three dimensional solid representing the displayed control region (step 38 ).
The above example provides a useful means of analyzing quality of batch processes whose recorded measurements are stored in large (historical) datasets. In this manner, a completed batch can be evaluated against various quality and performance yardsticks. The illustrated embodiment of the present invention may also be utilized to visualize data from as-yet non-completed (or running) batch process by predicting the end conditions of the data in advance while a batch is still running.
Multi-way PCA/PLS treats each process measurement at each time as a distinct variable, and accordingly, the values of variables defined by measurements extending from the current time until batch completion are unknown. Therefore, the illustrative embodiment of the present invention formulates an approach where a priori distribution for the variability of the unmeasured variables is assumed, and the running batch's score space end-condition is forecasted based on a partially complete record of measurements extending from the beginning of the batch to the current time. The geometry of the region representing this distribution may be defined in terms of the covariance of the observed and as yet unobserved measurements and the weightings that define each score in terms of each of the measurements (PCA loadings) as expressed in equation (1), which is discussed below. The PCA loadings are computed using historical data from the set of calibration batches. If the process measurements are assumed to have a Gaussian probability distribution, then this region will be ellipsoidal. Suppose v is a vector of random variables representing each of the process measurement at each time during the batch, organized in chronological order. Suppose further that the current batch is only ⅓ rd complete and the intention is to characterize the distribution of score end points based on the partial measurement trajectories available up to the current time. It is possible to split the sequence of variables into those which have been observed and those yet to be observed,
v = [ v measured v unknown ] ,
where v unknown represents the unobserved (latter ⅔ rd ) component of the data vector. If Σ represents the overall covariance of v evaluated from the calibration data, and W is the matrix of loadings for each score, then the variable defining the score vector S for the running batch can be expressed as:
S = Wv = [ W 1 W 2 ] [ v measured v unknown ] ,
where W 1 and W 2 are components of W decomposed based on the lengths of v measured and v unknown . S is thus a vector with unknown components (W 2 V unknown being the unknown part). If we assume a Gaussian distribution for the variance of v unknown , then the mean and covariance of S can be expressed as:
μ( S )=( W 1 +W 2 Σ 21 Σ 11 −1 ) v measured , cov ( S )= W 2 (Σ 22 −Σ 21 Σ 11 −1 Σ 12 ) W 2 T (1)
Here, μ(.) represents the conditional mean and cov(.) represents the conditional covariance of the current batch's score vector based on the measurements to date. Σ 11 , Σ 21 etc are sub-matrices extracted from Σ, depending upon the relative lengths of v measured and v unknown . Geometrically, the regions representing sets of scores (that represent likely end points up to some confidence level) will be ellipsoidal if the distribution of process measurements is Gaussian. The center of the ellipsoid is the expected value of the score vector μ(S), while the size is proportional to the square-root of the eigenvalues of the covariance matrix cov(S). Thus, larger the uncertainty in data (larger covariance), the larger is the size of the corresponding forecast region (ellipsoid). Depending upon the nature of a particular process, different assumptions can be made about the variance of the unmeasured variables. This method of representing uncertainty in forecasts of a running batch's end-conditions as multi-dimensional solids is lacking in conventional visualization methods for process data.
For the current example, the forecasted regions for a normal and a faulty test batch (⅓ rd complete) appear as shown by a first 40 and second 44 ellipsoids in FIG. 6 . A control region 40 is also displayed. The intersection of the in-control region 40 with the forecasted end-point region provides a measure of the likelihood that the running batch will end up in the in-control region. In the following three cases, a definitive decision can be made about the process behavior. If the predicted score region 52 is large and encloses the in-control region 50 as shown in FIG. 7A , a decision cannot be made because of the high level of uncertainty in the location of the batch scores. The plant operator must wait until more measurements become available. If the in-control region 50 completely encloses the forecasted score region, 52 as shown in FIG. 7B , then there is a strong probability that the batch will have similar results to the calibration batches and the operator does nothing. However, if the two regions 50 and 52 are disjointed as shown in FIG. 7C , then the batch may be off course and may require adjustments.
The sequence of steps followed by the illustrative embodiment of the present invention to display three dimensional visualizations of process data from ongoing processes is set forth in FIG. 8 . The sequence begins with batch process data being collected from an ongoing process (step 70 ). Statistical analysis is performed on the process data prior to the end of the process (step 72 ). An indicator of process condition is determined based in part on forecasted future process data values (step 74 ). The indicator of process condition suggests probable end point data values. A determined control region and an indicator of process condition are then displayed in a three dimensional view in for a user (step 76 ). The superposition of the two solids on the display indicates whether the ongoing process needs to be altered or not.
In addition to characterizing the amount of disjointedness, volume visualization as used in the illustrative embodiment of the present invention may provide an indication of the direction in score-space of any deviation of the set of likely score end points from the control region. If the scores have physical meaning then this orientation information can provide an indication of the cause of the evolving aberrant behavior and decision support for taking mid-course corrective action.
A number of visualization techniques are used to make these inferences from the visualizations of score end point sets and the ‘in control’ region. The color and transparency (opacity) of solids may be varied in order to view their relative locations or embedment clearly. The viewpoint of the displayed values may be rotated to view the surface from any direction, to ascertain the extent and the direction of intersections between the forecasted end-point region and the in-control region. The lighting conditions may be varied, the brightness altered, and the motion of camera light and viewpoint may be animated to assist in analysis of intersecting or superposing surfaces.
Further insight into the progress of a batch can be gained by viewing the evolution of the forecasted end-point regions. The uncertainty in forecasting, and consequently the sizes of the forecasted regions, will reduce as the batch progresses and more measurements become available. Thus, at the end of the batch the size of the forecast region diminishes to a single point representing a unique score vector. For an abnormal batch the forecast regions could diverge away from the in-control region as more measurements become available. The ability to assess a potential trend towards a process upset by viewing the progression of the regions of uncertainty is made possible by effective use of color, lighting and transparency control of intersecting/superposing solids. As each new measurement becomes available, a new (smaller) ellipsoid is superposed, and may be distinguished from the existing ellipsoids by using a higher opacity (less transparency), and a darker color. For example, a “HSV” (hue-saturation-value) coloring scheme available in MATLAB may be chosen in which the colors vary from a light orange to a deep red. The in-control region is shown by a wire-mesh, which enables easy view of its intersection of forecasted end-point regions.
FIG. 9 depicts the visual controls provided by the illustrative embodiment of the present invention. A control region 80 is bounded with a wire mesh effect. Different shaded regions 82 , 84 of displayed data intersecting the control region with the later measurements appearing smaller and darker. Also available are user interface controls for the display allowing the user to adjust the transparency of the control region 86 and a slider 88 to adjust the forecasted end point region.
The visualization tools of the illustrative embodiment of the present invention allow the visualization to be extended to more than to 3-dimensional spaces. Indeed, the score spaces usually have more than 3 dimensions, (although this number is usually not large in practice). Graphical methods that allow querying greater-than-three dimensional score spaces by interactive projections from score regions in greater than 3 dimensions onto 3-dimensional volumes extend the visualization benefits to processes described by arbitrary numbers of scores.
The illustrative embodiment of the present invention creates “data panners” (described below) that allow the user to visualize greater than three dimensional solids by projecting them onto 3 dimensions and interactively varying the geometry of the projection. The present invention also allows superimposing the 3 dimensional projections obtained to view a sequence of 3 dimensional cross-sections of the higher dimensional forecasted end-point region. Interactive data panning along higher dimensions may be made possible by MATLAB handle graphics tools. An example of such a panner is shown in FIG. 10 .
The panner 100 provides a two dimensional view of the 4 th and 5 th dimension of score data. Slicing projections are performed along 4th and 5th dimensions to obtain the locus of projection in a 3-D plane. An icon 102 in the region of valid projections allows a user to select a projection plane. The panner 100 provides an interactive way of doing so in real-time. As the icon 102 is moved by mouse, the projections update automatically. The data panner 100 is cross referenced with the three dimensional display of process data values.
If there are n scores then the region describing the score end point uncertainly will exist in an n dimensional space. The n dimensional solid may be visualized by fixing n-3 of the score coordinates at values of a point within the n dimensional solid, and then viewing the set of all possible values of the 3 remaining coordinates for points in the solid within a 3 dimensional graphical projection. The user can visualize the n dimensional solid by varying the location of the n-3 initial coordinates, and viewing the behavior of the 3 dimensional graphical projections describing admissible values of the remaining coordinates. Selection of the initial n−3 coordinates requires the user to select them with the mouse from a graphical description of the set of possible values defined by points in the n dimensional solid. This graphical tool is labeled a “data panner” herein.
The process visualization of the present invention follows certain rules in visualizing process data. If the n dimensional solid is ellipsoidal, each of the views will be a representation of a 3 dimensional ellipsoid. If n is 4 dimensions, the data panner requires the selection of a single coordinate from an interval. If n is 5 dimensions, the data panner requires the selection of a pair of coordinates from a 2 dimensional shape. This can be achieved by selecting a single point with a mouse click. In most cases the scores selected with the data panner will be the less significant scores, since in general this will result in less drastic movement of the score view as the data panner is manipulated.
In the illustrative embodiment of the present invention, a dynamic link is created between the panner that controls the projection planes along the higher (>3) dimensions and the projected 3-D views. Thus, as a user moves the mouse to choose a projection point along 4 th and 5 th dimensions, the corresponding 3-D projections of the in-control region and forecasted end-point region update automatically. In FIG. 10 , the ellipse 104 (in the right-hand-side panner) marks the region defined by the 4 th and 5 th score coordinates of points in the 5 dimensional solid defining the set of score end points. The user can grab the blue star-shaped icon 102 and move it around inside the ellipse. Each location of this icon defines a pair of orthogonal surfaces along which the section in 4 th and 5 th dimensions are taken. The present invention may also be extended to non-orthogonal slicing without departing from the scope of the present invention. Arbitrary surfaces encompassing one or more dimensions may be defined along which the projection could be taken. Such slicing surfaces would be user-defined.
To gain a better understanding of the relative locations and the extent of intersection between the two regions, it is possible to superpose the projections from different cross sections along higher dimensions. This is achieved by using a “data panner”, also referred to as a “projection selector”. The primary three components are chosen for visualization of forecasted batch end points. The remaining n−3 components are used to define an n−3 dimensional region along which valid projections can be taken. A trail of the projected 3-D regions can be visualized as a function of the position of the blue-star icon. The resulting view is shown in FIG. 11 . The data panner 100 also has three score selectors 110 , 112 and 114 that a user manipulates to select score (explained below). The selection may be done in real time. The superposed projections of the in-control region and the forecasted end-point regions appear as different colored clouds 116 and 118 . The loci-clouds represent intersecting regions in 3-D space for a given choice of three principal components.
The approach of analyzing projections of higher dimensional spaces is completed by providing the ability to choose any 3 out of n (n: dimension of score space) principal components for drawing the projections. Since there are 10 ways of choosing unique triplets out of a set of 5 objects, there is a choice of 10 different projection views in 3-D space, for a 5-dimensional PCA model. The combination of abilities to superpose projections and choose any 3 score components for projection subspace provides the user with a rich set of options to monitor and query forecasted scores over the run of the process.
FIG. 12 is a flow chart of the sequence of steps followed by the illustrative embodiment of the present invention to use the data panner to visualize more than three dimensions of scores. The sequence begins with batch process data being collected from an ongoing process (step 120 ). An indicator of process condition is determined based upon statistical analysis of the process data (step 122 ). The user selects three dimensions of scores from the n dimensions of data (step 124 ). A control region of acceptable variability and the indicator of process condition are then displayed in three dimensions (step 126 ). A separate region for the remaining n−3 components is then drawn that indicates the locus of locations where valid projections can be taken. An icon is then displayed inside this projection selector region that represents the location of the current projection that is being displayed in the 3-dimensional volume view ( FIG. 11A ). The three dimensional view is then altered in response to user manipulation of the n−3 icon (step 130 ).
The graphical visualization techniques of the present invention may be used for not only detecting but also modifying/correcting an aberrant process behavior. Visualization of the dependence of end point regions on various hypothetical future values of key variables can help an operator decide which input changes may move the score region back into the ‘in control’ region. Aberrant behavior may be corrected by simply holding one of the input variables to a constant value for the remaining course of the process.
For example, for a running process, at a particular logging instant, a fault may be detected by observing that the in-control region and the forecasted batch end-point region do not intersect. A particular process input variable may then be held to an adjustable constant value from the current time until the end of the batch in order to observe the effect of the constant value on the forecasted region; in affect modifying the forecast for hypothetical scenario. Various constant values for the chosen process variable can be tested to evaluate which scenario maximizes the proximity between the two regions. Since multiple variables may be under the user's control this procedure may be repeated for other variables.
FIG. 13 shows the current forecast 150 for a batch end point. The displayed regions 152 and 154 do not intersect, which is an indication of a fault. To correct the behavior, a user selects one variable at a time from the popup menu. The currently selected variable appears in edit box below, which is “He Press (helium pressure)” 156 in the figure. For the chosen variable, the line 158 running through the forecasted end-point region indicates the locus of the forecasted regions' location for various fixed values of that input (“He Press”) from the current time until batch completion. The value of the input variable is changed using the slider 160 , which is dynamically linked to the position of the forecasted end-point region. The chosen value is displayed in a text area 162 located towards the right of the slider.
FIG. 14 shows controls to rotate the whole view 170 and its lighting and color properties can be adjusted interactively using the figure 172 and camera 174 toolbars. The zooming option 166 provides additional control over querying the locations and intersections of these surfaces. Indeed, this type of graphical exploration maneuver is essential to judging whether the end point region locus intersects the ‘in control’ region. FIG. 14 depicts a process being brought to normal behavior (“in control”), by assigning fixed values for variables−TCP Tuner 175 , RF Load 176 , and TCP Load 177 .
FIG. 15 describes the modification to the multi-way PCA unfolding algorithm to account for a variable that is assumed to be held constant until the end of the batch: Multi-way PCA method involves unfolding of measurements of all process variables into a single data vector. Fixing a single process variable to a constant value K 190 amounts to re-organizing the data to keep the known values together with the already-measured variables. Thus, hypothetical data (of value K) is treated as if it were known into the future. Conditional means and covariance are calculated for the new data split, since the partitioning of matrices W into W 1 , W 2 , and Σ into Σ 11 , Σ 12 , Σ 21 , Σ 22 changes.
The present invention also allows the process data to be visualized by prescribing time-dependent trajectories for several process inputs together, rather than hold them to constant levels. This forces a different reshaping of the forecasted region. Similarly, limits on the variability of certain process variables might be required. These limits would also correspond to regions similar to the forecasted end-point regions in the score space. The intersection of variable-constraint region with the in-control region would help in evaluating the feasibility of achieving desired performance under prescribed constraints.
Batch execution of simulations is analogous to batch processing in manufacturing, and the monitoring and visualization techniques described above may also be applied to monitor the behavior of sequences of simulations. Specifically, they can be used to monitor the progress of individual simulations, detect simulation runs which deviate from an ‘in-control’ region defined by a normative ensemble of simulations, and provide geometrical representations of various likely simulation end points under various conditions. The illustrative embodiment of the present invention may be implemented to perform batch simulation monitoring within a simulation block language such as Simulink implemented in the form of a simulation block or other form, and also within a batch simulation tool such as the Simulation and Test Workshop. Those skilled in the art will recognize that other simulation environments are also possible within the scope of the present invention.
The illustrative embodiment of the present invention may also be used to analyze a continuous rather than a batch process. The analysis determines an indicator of process condition based on the current state of the process defining a single point in n dimensional score space representing the current process condition. The user establishes ranges of possible values for certain process set points that would result from one or more user-initiated control moves. The set of scores defined by the current process condition, and all possible user-defined values of the said process set points, describe a region of scores representing process conditions achievable by adjusting the process set points within the specified ranges. A display of the region of potential process conditions and a control region of acceptable variability in three dimensions is generated for a user. The user is able to manipulate various features of the display in order to assess whether any of the set points in the user defined range(s) would cause the process condition to deviate from the control region, and so simulate the potential outcome of making those control adjustments. These graphical manipulations may include varying the viewpoint of the control region and condition trajectory, adjusting the opacity of the control region, zooming in on certain subsets, rotating the entire view, changing the origin and intensity of the simulated lighting of the view, manipulating contract and colors, visually ‘cutting open’ the control region in order to visualize the relationship between the process condition, its trajectory and the interior of the control region.
Since certain changes may be made without departing from the scope of the present invention, it is intended that all matter contained in the above description or shown in the accompanying drawings be interpreted as illustrative and not in a literal sense. Practitioners of the art will realize that the system configurations depicted and described herein are examples of multiple possible system configurations that fall within the scope of the current invention. For example, the present invention may be practiced in other block diagram execution environments such as text based simulation environments. Likewise, the sequence of steps utilized in the illustrative flowcharts are examples and not the exclusive sequence of steps possible within the scope of the present invention. | A method for forecasting batch end conditions through their depiction as a multi-dimensional regions of uncertainty is disclosed. A visualization of the current condition of a continuous process and visualization of the simulated effect of user control moves are generated for a user. Volume visualization tools for viewing and querying intersecting solids in 3-dimensional space are utilized to perform the process visualization. Interactive tools for slicing multi-dimensional (>3) regions and drawing superimposed projections in 3-D space are provided. Additionally, graphical manipulation of the views of process conditions is accomplished by changing the hypothetical future values of contributing variables online in order to provide users the ability to simulate the effect of proposed control actions. The illustrative embodiment of the present invention may also be utilized in combination with a graphical programming environment supporting the execution and simulation of block diagrams and correspondingly generated process data. The scores representing the process condition may depend on estimated physical quantities as well as representations of process variability. | 6 |
RELATED APPLICATIONS
[0001] The present application claims priority benefit of U.S. Provisional Application No. 60/260,124 filed Jan. 5, 2001 which is herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to Adeno-associated virus vectors. In particular, it relates to Adeno-associated virus vectors with modified capsid proteins and materials and methods for their preparation and use.
BACKGROUND
[0003] Adeno-associated virus (AAV) is a replication-deficient parvovirus, the single-stranded DNA genome of which is about 4.7 kb in length including 145 nucleotide inverted terminal repeat (ITRs). The nucleotide sequence of the AAV serotype 2 (AAV2) genome is presented in Srivastava et al., J. Virol., 45: 555-564 (1983) as corrected by Ruffing et al., J. Gen. Virol., 75: 3385-3392 (1994) Cis-acting sequences directing viral DNA replication (rep), encapsidation/packaging and host cell chromosome integration are contained within the ITRs. Three AAV promoters, p5, p19, and p40 (named for their relative map locations), drive the expression of the two AAV internal open reading frames encoding rep and cap genes. The two rep promoters (p5 and p19), coupled with the differential splicing of the single AAV intron (at nucleotides 2107 and 2227), result in the production of four rep proteins (rep 78, rep 68, rep 52, and rep 40)from the rep gene. Rep proteins possess multiple enzymatic properties which are ultimately responsible for replicating the viral genome. The cap gene is expressed from the p40 promoter and it encodes the three capsid proteins VP1, VP2, and VP3. Alternative splicing and non-consensus translational start sites are responsible for the production of the three related capsid proteins. A single consensus polyadenylation site is located at map position 95 of the AAV genome. The life cycle and genetics of AAV are reviewed in Muzyczka, Current Topics in Microbiology and Immunology, 158: 97-129 (1992).
[0004] When AAV infects a human cell, the viral genome can integrate into chromosome 19 resulting in latent infection of the cell. Production of infectious virus does not occur unless the cell is infected with a helper virus (for example, adenovirus or herpesvirus). In the case of adenovirus, genes E1A, E1B, E2A, E4 and VA provide helper functions. Upon infection with a helper virus, the AAV provirus is rescued and amplified, and both AAV and adenovirus are produced.
[0005] AAV possesses unique features that make it attractive as a vaccine vector for expressing immunogenic peptides/polypeptides and as a vector for delivering foreign DNA to cells, for example, in gene therapy. AAV infection of cells in culture is noncytopathic, and natural infection of humans and other animals is silent and asymptomatic Moreover, AAV infects many mammalian cells allowing the possibility of targeting many different tissues in vivo. Replication of the viral DNA is not required for integration, and thus helper virus is not required for this process. The AAV proviral genome is infectious as cloned DNA in plasmids which makes construction of recombinant genomes feasible. Furthermore, because the signals directing AAV replication, genome encapsidation and integration are contained within the ITRs of the AAV genome, some or all of the internal approximately 4.3 kb of the genome (encoding replication and structural capsid proteins, rep-cap) may be replaced with foreign DNA such as a gene cassette containing a promoter, a DNA of interest and a polyadenylation signal. The rep and cap proteins may be provided in trans. Another significant feature of AAV is that it is an extremely stable and hearty virus. It easily withstands the conditions used to inactivate adenovirus (56° to 65° C. for several hours), making cold preservation of rAAV-vectors less critical. AAV may even be lyophilized. Finally, AAV-infected cells are not resistant to superinfection.
[0006] Recent research on AAV has therefore involved attempts to modify the viral genome. As the range of cells that AAV will infect is so broad, some researches have focused on modifying the virus so that it targets specific types of cells for infection. The cellular range or tropism of the virus is determined by the binding of AAV capsid protein(s) to receptor and/or coreceptor proteins expressed on the surface of target cells. Heparin-sulfate proteoglycan (HSPG) is the primary cellular attachment receptor for AAV2. In attempts to enable AAV to bind other cellular receptors, mutagenesis of the AAV capsid-encoding DNA to encode heterologous targeting peptides as part of a capsid protein has produced varying results. For example, Girod et al. ( Nature Medicine, 5: 1052-1056, 1999) describes AAV2 insertional mutants generated to target L14-specific integrin receptors. These mutant AAV2 vectors expressed capsid proteins which had a fourteen amino acid peptide comprising the RGD domain of the laminin fragment P1 inserted at six different sites. Rabinowitz et al. ( Virology, 265: 274-285, 1999) attempted to identify capsid domains and positions which were capable of tolerating insertions without loss of function. Related PCT application WO 00/28004 describes the modified capsid proteins containing insertions such as melanocyte stimulating hormone, poly-histidine tracts, poly-lysine tracts, an RGD domain and bradykinin. Only a few of the modified capsid proteins could be incorporated into functional viral particles and titers of the viruses were drastically lower than wild-type virus.
SUMMARY OF THE INVENTION
[0007] The present inventors recognized a need in the art for identification of sites in the AAV capsid protein(s) from which peptides/polypeptides of interest may be presented in a desired conformation to allow the development of AAV vectors that deliver DNA to specific target cells and the development of AAV vectors that present/display on their surface immunogenic peptides/polypeptides. Their invention is based on the elucidation of sites/regions in the AAV2 capsid protein that are amenable to insertion of heterologous peptides, the development of scaffolding sequences required for proper conformation of peptides, and the construction of AAV2 vectors with altered tropism. The full length nucleotide sequence of the wild type AAV2 vector is set out as SEQ ID NO: 12. The amino acid sequence of VP1capsid protein (SEQ ID NO: 13) is encoded by the nucleotides 2203-4410 of SEQ ID NO: 12, the amino acid sequence of VP2 capsid protein (SEQ ID NO: 14) is encoded by nucleotides 2614-4410 of SEQ ID NO: 12 and the amino acid sequence of VP3 capsid protein (SEQ ID NO: 15) is encoded by nucleotides 2809-4410 of SEQ ID NO: 12.
[0008] The present invention provides AAV vectors (viral particles) encoding capsid proteins that comprise insertions of amino acids of interest (i.e., peptides or polypeptides). Preferably, the AAV vectors are AAV2 vectors. Also preferably, DNA encoding the insertions follows the cap gene DNA encoding amino acid position 139 and/or position 161 in the VP1/VP2 capsid region, and/or amino acid position 459, 584, 588 and/or 657 in the VP3 region. While the capsid sites/regions amenable to insertions have been described herein with respect to AAV2, those skilled in the art will understand that corresponding sites in other parvoviruses, both autonomously-replicating parvoviruses and other AAV dependent viruses, are also sites/regions amenable to insertions in those viruses. The amino acids of interest may impart a different binding/targeting ability to the vector or may themselves be immunogenic. As a result, the vectors of the invention exhibit altered characteristics in comparison to wild type AAV, including but not limited to, altered cellular tropism and/or antigenic properties. The invention also contemplates cells, plasmids and viruses which comprise polynucleotides encoding the capsid proteins of the invention.
[0009] It is contemplated that in addition to amino acids of interest, amino acids serving as linker/scaffolding sequences as described herein may be included in the AAV vector capsid insert to maintain the functional conformation of the capsid. The linker/scaffolding sequences are short sequences which flank the insertion of interest in the mutated capsid protein. For example, the insertion may have the amino acids TG at its amino terminus and the tripeptide ALS, GLS or LLA at its carboxy terminus.
[0010] Techniques to produce AAV vectors, in which a AAV genome to be packaged, rep and cap genes, and helper virus functions are provided to a cell are standard in the art. Production of AAV vectors requires that the following components are present within a single cell (denoted herein as a packaging cell): a rAAV construct consisting of a DNA of interest flanked by AAV inverted terminal repeats, an AAV helper construct containing the capsid gene (which may or may not be comprise an insert) and the rep gene, and an adenovirus helper plasmid or infected with an adenovirus. The rAAV construct may be delivered to a packaging cell by transfection in a plasmid, infection by a viral genome or may be integrated into the packaging cell genome. The AAV helper construct may be delivered to a packaging cell by transfection of a plasmid or integrated into the packaging cell genome. The adenovirus helper plasmid or adenovirus may be delivered to the packaging cell by transfection/infection. The term “helper virus functions” refers to the functions carried out by the addition of an adenovirus helper plasmid or infection of adenovirus to support production of AAV viral particles.
[0011] One method generating a packaging cell with all the necessary components for AAV production is the triple transfection method. In this method a cell such as a 293 cell is transfected with the rAAV construct, the AAV helper construct and a adenovirus helper plasmid or infected with adenovirus. The advantages of the triple transfection method are that it is easily adaptable and straightforward. Generally, this method is used for small scale vector preparations.
[0012] Another method of generating a packaging cell is to create a cell line which stably expresses all the necessary components for AAV vector production. For example, a plasmid expressing the rAAV construct, a helper construct expressing the rep and cap proteins (modified or wild type) and a selectable marker, such as Neo, are integrated into the genome of a cell. The packaging cell line is then infected with a helper virus such as adenovirus. The advantages of this method are that the cells are selectable and are suitable for large-scale production of the vector.
[0013] In another aspect the invention provides AAV helper constructs encoding a AAV cap gene comprising DNA encoding an insertion of one or more amino acids in the encoded capsid protein(s). The insertion is at a position of the encoded capsid protein(s) that is exposed on the surface of an AAV vector comprising the capsid protein(s) and that does not disrupt conformation of the capsid protein(s) in a manner that prevents assembly of the vector or infectivity of the vector. Limited by these criteria, the size of the insert may vary from as short as two amino acids to as long as amino acids encoding an entire protein. Also provided are cells that stably or transiently produce AAV vectors of the invention. Methods of producing AAV vectors using such cells are contemplated by the invention.
[0014] In one embodiment, the AAV vectors of the invention comprising capsid proteins with binding/targeting amino acids inserted are useful for the therapeutic delivery and/or transfer of nucleic acids to animal (including human) cells both in vitro and in vivo. Nucleic acids of interest include nucleic acids encoding peptides and polypeptides, such as therapeutic (e.g., for medical or veterinary uses) peptides or polypeptides. A therapeutic peptide or polypeptide is one that may prevent or reduce symptoms that result from an absence or defect in a protein in a cell or person. Alternatively, a therapeutic peptide or polypeptide is one that otherwise confers a benefit to a subject, e.g., anti-cancer effects. As a further alternative, the nucleic acid may encode a reporter peptide or protein (e.g., an enzyme). In yet still another alternative, the nucleic acid of interest may be an antisense nucleic acid or a ribozyme.
[0015] In another embodiment, the AAV vectors are useful as vaccines. The use of parvoviruses as vaccines is known in the art. Immunogenic amino acids (peptides or polypeptides) may be presented as inserts in the AAV vector capsid. Alternatively, immunogenic amino acids may be expressed from a heterologous nucleic acid introduced into a recombinant AAV genome and carried by the AAV vector. If the immunogenic amino acids are expressed from a recombinant AAV genome, the AAV vector of the invention preferably exhibits an altered cellular tropism and comprises a capsid protein with an insertion of targeting amino acids that are different from those of wild type AAV. Immunogenic amino acids may be from any source (e.g., bacterial, viral or tumor antigens).
[0016] AAV vectors of the invention that exhibit an altered cellular tropism may differ from wild type in that the natural tropism of AAV may be reduced or abolished by insertion or substitution of amino acids of interest in a capsid protein of the vector. Alternatively, the insertion or substitution of the amino acids may target the vector to a particular cell type(s) perhaps not targeted by wild type AAV. Cell types of interest contemplated by the invention include, for example, glial cells, airway epithelium cells, hematopoietic progenitors cells and tumor cells. In preferred embodiments, capsid amino acids are modified to remove wild type tropism and to introduce a new tropism. The inserted or substituted amino acid may comprise targeting peptides and polypeptides that are ligands and other peptides that bind to cell surface receptors and glycoproteins as well as fragments thereof that retain the ability to target vectors to cells. The targeting peptide or polypeptide may be any type of antibody or antigen-binding fragment thereof that recognizes, e.g., a cell-surface epitope. The binding domain from a toxin can be used to target the AAV vector to particular target cells of interest. It is also contemplated that AAV vectors of the invention may be targeted to a cell using a “nonclassical” import/export signal peptide (e.g., fibroblast growth factor-1 and -2, interleukin 1, HIV-1 Tat protein, herpes virus VP22 protein, and the like).
[0017] Also contemplated as targeting peptides are peptides that direct uptake of the AAV vector by specific cells. For example, a FVFLP peptide (SEQ ID NO: 18) triggers uptake by liver cells. Another peptide contemplated to direct uptake by cancer cells is the RGD peptide, e.g., 4C-RGD. The RGD domain is known to mediate interactions between extracelluar matrix proteins and integrin receptors located on the surface of cancer cells. It is contemplated that the insertion of an RGD peptide into the capsid of the AAV vector will act as a cell entry mechanism specific to cancer cells. The receptor-binding peptide from luteinizing hormone is also contemplated as a peptide which when inserted into the capsid of an AAV vector will direct entry into ovarian cells since ovarian cells express luteinizing hormone receptors.
[0018] Other targeting peptide contemplated influence cellular trafficking of viral particles. Phage display techniques, as well as other techniques known in the art, may be used to identify peptides that recognize, preferably specifically, a cell type of interest. Alternatively, the targeting sequence comprises amino acids that may be used for chemical coupling (e.g., through amino acid side groups of arginine or lysine residues) of the capsid to another molecule that directs entry of the AAV vector into a cell.
[0019] The present invention also encompasses modified AAV vectors, the capsid protein(s) of which are biotinylated in vivo. For example, the invention contemplates AAV capsids engineered to include the biotin acceptor peptide (BAP). Expression of the E. coli enzyme biotin protein ligase during AAV vector biosynthesis in the presence of biotin results in biotinylation of the AAV capsid proteins as they are made and assembled into viral particles.
[0020] In order to biotinylate the AAV viral particles, a system for expressing the biotin ligase enzyme in packaging cell lines is contemplated by the present invention. The invention provides for plasmids, such as the pCMV plasmid, which direct expression of the biotin ligase gene within the packaging cell line. For production of the biotinylated AAV vector the following components need to be transfected into a packaging cell: a rAAV vector comprising DNA of interest flanked by AAV inverted terminal repeats, an AAV helper construct containing a capsid gene with a BAP insert and the rep gene, adenovirus helper plasmid or infected with adenovirus, and the biotin ligase gene (BirA). In this system, the biotin ligase gene may be expressed by a plasmid including the BirA gene (such as pCMV-BirA) infection with an adenovirus which expresses the BirA gene or by using a packaging cell line that is stably transfected with the BirA gene.
[0021] It is contemplated that the biotinylated AAV viral particles will serve as substrates for conjugation of targeting motifs (e.g., monoclonal antibodies, growth factors, cytokines) to the surface of vector particles through utilizing avidin/strepavidin-biotin chemistry. In addition, the biotinylated AAV viral particles are contemplated to be useful for visualizing the biodistribution of the viral particles both in vivo and in vitro. The biotinylated viral particles can be visualized with fluorescence or enzymatically with labeled strepavidin compounds. Biotinylation is also useful for conjugating epitope shielding moieties, such as polyethylene glycol, to the AAV vector. The conjugation of shielding moieties allows the vector to evade immune recognition. Biotinylation of the AAV vector is also contemplated to enhance intracellular trafficking of viral particles through conjugation of proteins or peptides such as nuclear transport proteins. Biotinylation may also be used to conjugate proteins or peptides which affect the processing of AAV vector genomes such as increasing the efficiency of integration. In addition, biotinylation may also be used to conjugate proteins or peptides that affect the target cells, e.g., proteins that make a target cell more susceptible to infection or proteins that activate a target cell thereby making it a better target for the expression of a therapeutic or antigenic peptide.
[0022] The present invention also provides compositions comprising an AAV vector of the invention in a pharmaceutically acceptable carrier. The compositions may also comprise other ingredients such as diluents and adjuvants. Acceptable carriers, diluents and adjuvants are nontoxic to recipients and are preferably inert at the dosages and concentrations employed, and include buffers such as phosphate, citrate, or other organic acids; antioxidants such as ascorbic acid; low molecular weight polypeptides; proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, arginine or lysine; monosaccharides, disaccharides, and other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugar alcohols such as mannitol or sorbitol; salt-forming counterions such as sodium; and/or nonionic surfactants such as Tween, pluronics or polyethylene glycol (PEG).
[0023] Methods of eliciting an immune response to amino acids of interest are contemplated by the invention. The methods comprise a step of administering an immunogenic dose of a composition comprising a AAV vector of the invention to a animal (including a human person) in need thereof. In the methods, the immunogenic amino acids may be inserted in the AAV vector capsid protein(s) or may be encoded by a recombinant genome encapsidated as the AAV vector. An immunogenic dose of a composition of the invention is one that generates, after administration, a detectable humoral and/or cellular immune response in comparison to the immune response detectable before administration or in comparison to a standard immune response before administration. The invention contemplates that the immune response resulting from the methods may be protective and/or therapeutic.
[0024] Therapeutic methods of delivering and/or transferring nucleic acids of interest to a host cell are also contemplated by the invention. The methods comprise the step of administering a therapeutically effective dose of a composition comprising a AAV vector of the invention to an animal (including a human person) in need thereof. A therapeutically effective dose is a dose sufficient to alleviate (eliminate or reduce) at least one symptom associated with the disease state being treated. Administration of the therapeutically effective dose of the compositions may be by routes standard in the art, for example, parenteral, intravenous, oral, buccal, nasal, pulmonary, rectal, or vaginal.
[0025] Titers of AAV vector to be administered in methods of the invention will vary depending, for example, on the particular virus vector, the mode of administration, the treatment goal, the individual, and the cell type(s) being targeted, and may be determined by methods standard in the art.
DETAILED DESCRIPTION
[0026] The present invention is illustrated by the following examples that are not intended to limit the invention. Example I describes construction of AAV packaging plasmids encoding altered capsid proteins and analysis of the ability of the altered capsid proteins to be assembled into infectious AAV vectors. Example 2 presents assays for the surface expression of epitopes inserted in the altered capsid proteins. Example 3 describes experiments testing whether the AAV vectors retained HSPG-binding ability. Example 4 describes construction and characterization of a mutant AAV vector containing a double insertion within the capsid protein. Example 5 includes analysis of the effect of linker and scaffold sequences on the altered capsid proteins. Example 6 presents the results of experiments in which AAV vectors encoding capsid proteins with an insertion of an luteinizing hormone receptor binding peptide were able to transduce OVCAR-3 cells. Example 6 also discusses various indications amenable to use of AAV vectors of the invention. Example 7 and 8 describe fourteen additional modified AAV vectors, wherein the RGD-4C peptide motif was inserted into the capsid proteins. The experiments described in Example 9 demonstrate that the AAV-RGD vectors attach to and enter cells via integrin receptors. Example 10 demonstrates that the AAV-RGD vectors were capable of mediating gene delivery via integrin receptors. Example demonstrates that the AAV-RGD vectors transferred genes to ovarian adenocarcinoma cell lines. Example 12 describes AAV mediated eGFP gene delivery to human ovarian tumor xenografts established in SCID mice. Example 13 describes construction of mutant AAV vectors which are biotinylated in vivo through an insertion of the biotin acceptor peptide in the capsid protein. Finally, Example 14 describes a packaging system for biotinylated AAV vectors.
EXAMPLE 1
[0027] In order to identify sites within the AAV2 capsid that could tolerate insertion of targeting epitopes, an extensive site-specific mutagenesis strategy was designed. Regions of the AAV2 capsid DNA to be modified were chosen by analyzing data from a number of sources to predict which ones encoded capsid amino acids that were exposed on the surface of the virion and which encoded amino acids that could be replaced with other amino acids without significantly altering the conformation of the rest of the capsid protein(s). One source of data was a comparison of structural information from five related autonomous parvoviruses. The five parvoviruses had solved virion structures and included canine parvovirus (CPV) (Tsao et al., Science, 251: 1456-1464 and Wu et al., J. Mol. Biol, 233: 231-244), feline panleukopenia virus (FPV)(Agbandje et al., Proteins, 16: 155-171), minute virus of mice (MVM)(Agbandje-McKenna et al., Structure, 6: 1369-1381 and Llamas-Saiz et al., Acta Crystallogr. Sect. D. Biol. Crystallogr., 53: 93-102), parvovirus B19 (B19)(Chipman et al., Proc. Natl. Acad. Sci. USA, 93: 7502-7506) and Aleutian mink disease parvovirus (ADV)(McKenna et al., J. Virol., 73: 6882-6891). This information was compared to a computer-predicted secondary structure of the AAV2 capsid based on its known primary amino acid sequence. Other sources of data were previous reports of immunogenic regions of the AAV2 capsid and previous reports of effects of random capsid mutations. Finally, the AAV2 capsid primary amino acid sequence was compared with that of other AAV and other parvoviridae for regions of defined secondary structure to create a model of the AAV2 capsid. From the model sites for insertion of small peptides two to fifteen amino acids in length were chosen. A series of thirty-eight virus mutants containing peptide insertions at twenty-five unique sites within the AAV2 capsid protein was generated. Most of the insertions were within the VP1 capsid protein (19/25), four were within the VP1 unique region and two were within the VP1/VP2 unique region. Epitopes inserted within the VP3 protein are expected to be displayed on every capsid monomer within the AAV virion (60/virion). Insertions within the VP1 or VP1/VP2 unique regions would be expected to be displayed three and six times, respectively, per virion.
[0028] Site-directed mutagenesis was performed on plasmid pUC-Cap (a subclone of the AAV2 Rep and Cap open reading frames (ORF)). Mutagenesis was confirmed by restriction endonuclease digestion. The altered Cap genes were then substituted for the wild-type AAV2 sequences in plasmid pACG2 to generate the series of mutant helper plasmids described in Table 1 below, wherein epitope AgeI is the amino acids encoded by an AgeI restriction site, epitope NgoMI is the amino acids encoded by an NgoMI restriction site, epitope 4C-RGD is a cyclic RGD-based peptide (CDCRGDCFC; SEQ ID NO: 10) that has been shown to bind a number of integrins, including α v β 3 , α v β 5 , α 5 β 1 , α 5 β 1 , α 3 β 1 , α 2 β 1 and α 6 β 1 , present on the surface of mammalian cells that is useful for targeting to tumor endothelium and other cell types, epitope BPV is a peptide from bovine papilloma virus (TPPYLK; SEQ ID NO: 16), and epitope LH is a receptor-binding peptide from luteinizing hormone (HCSTCYYHKS; SEQ ID NO: 17). Plasmid nomenclature in the Table 1 can be understood by reference to plasmid pACG-A139 wherein pACG refers to the starting plasmid in which mutant cap sequences were inserted and A139 refers to insertion of an AgeI restriction site after position 139 of the capsid, and by reference to plasmid pACG-A139BPV/GLS wherein BPV indicates the peptide of interest that is inserted and /GLS indicates inclusion of linker amino acids at the carboxy terminus of the inserted epitope.
TABLE 1 Mutant AAV Packaging Plasmids Mutant Plasmid Designation Location Insertion (epitope) pACG-A26 VP1 TG (Age I) pACG-A46 VP1 TG (Age I) pACG-A115-4C- VP1 TGCDCRGDCFCGLS (SEQ ID RGD/GLS NO: 1) (4C-RGD) pACG-A120 VP1 TG (Age I) pACG-A139 VP2 TG (Age I) pACG-A139BPV/GLS VP2 TGTPFYLKGLS (SEQ ID NO: 2) (BPV) pACG-A139LH/GLS VP2 TGHCSTCYYHKSGLS (SEQ ID NO: 3) (LH) pACG-A161BPV/ALS VP2 TGTPFYLKALS (SEQ ID NO: 4) (BPV) pACG-A161BPV/LLA VP2 TGTPFYLKLLA (SEQ ID NO: 5) (BPV) pACG-A161BPV/GLS VP2 TGTPFYLKGLS (SEQ ID NO: 2) (BPV) pACG-A161LH/GLS VP2 TGHCSTCYYHKSGLS (SEQ ID NO: 3) (LH) pACG-A312 VP3 TG (Age I) pACG-N319 VP3 AG (NgoMI) pACG-A323-4C- VP3 TGCDCRGDCFCGLS (SEQ ID RGD/GLS NO: 1) (4C-RGD) pACG-A339BPV VP3 TGTPFYLK (SEQ ID NO: 6) (BPV pACG-A375BPV VP3 TGTPFYLK (SEQ ID NO: 6) (BPV) pACG-A441 VP3 TG (Age I) pACG-A459 VP3 TG (Age I) pACG-A459BPV/GLS VP3 TGTPFYLKGLS (SEQ ID NO: 2) (BPV) pACG-A459LH/GLS VP3 TGHCSTCYYHKSGLS (SEQ IS NO: 3) (LH) pACG-A466 VP3 TG (Age I) pACG-A480-4C- VP3 TGCDCRGDCFCGLS (SEQ ID RGD/GLS NO: 1) (4C-RGD) pACG-N496 VP3 AG (NgoMI) pACG-A520LH/GLS VP3 TGHCSTCYYHKSGLS (SEQ ID NO: 3) (LH) pACG-A520BPV/LLA VP3 TGTPFYLKLLA (SEQ ID NO: 5) (BPV) pACG-A540 VP3 TG (Age I) pACG-N549 VP3 AG (NgoMI) pACG-N584 VP3 AG (NgoMI) pACG-A584BPV/ALS VP3 TGTPFYLKALS (SEQ ID NO: 4) (BPV) pACG-A584BPV/LLA VP3 TGTPFYLKLLA (SEQ ID NO: 5) (BPV) pACG-A584BPV/GLS VP3 TGTPFYLKGLS (SEQ ID NO: 2) (BPV) pACG-N472 VP3 AG (NgoMI) pACG-A587BPV/ALS VP3 TGTPFYLKALS (SEQ ID NO: 4) (BPV) pACG-A587BPV/LLA VP3 TGTPFYLKLLA (SEQ ID NO: 5) (BPV) pACG-A587BPV/GLS VP3 TGTPFYLKGLS (SEQ ID NO: 2) (BPV) pACG-A595-4C- VP3 TGCDCRGDCFCGLS (SEQ ID RGD/GLS NO: 1) (4C-RGD) pACG-A597-4C- VP3 TGCDCRGDCFCGLS (SEQ ID RGD/GLS NO: 1) (4C-RGD) pACG-A657 VP3 TG (Age I)
[0029] The mutant AAV packaging plasmids were tested for their ability to generate AAV vectors with altered capsids by triple transfection with plasmid pAAV-LacZ (a plasmid containing LacZ flanked by AAV ITRs) and pXX6-80 (a plasmid containing Adenovirus helper DNA) according to established procedures. AAV vector preparations were assessed for particle formation and vector infectivity. Particles were identified by ELISA using A20 monoclonal antibody, whereas DNA-containing particles were identified by dot-blot and/or PCR. Vector particles were tested for infectivity by cellular transduction assay on Adenovirus-infected C12 cells. Capsid mutants were grouped into three types. Capsid mutants that did not give rise to any viral particles were classified as Type I (7/38). Mutants that produced non-infectious particles were classified as Type II ( 11/38) and mutants that produced fully infectious viral particles were classified as Type III (20/38). See Table 2 below wherein the actual titers are listed as values for comparison with the wild type titer unless the titer (−) is four orders of magnitude or more less than wild type vector and a titer (+) is below the sensitivity of DNA dot blot but detectable by PCR.
TABLE 2 Mutant AAV Vector Characterization Particle titer Mutant Vector Infections Mutant Designation Dot-blot A20 ELISA titer Type AAV-A26 (+) 7.5 × 10 7 — II AAV-A46 9.2 × 10 7 8.0 × 10 7 1.2 × 10 3 III AAV-A115-4C- 5.6 × 10 7 7.5 × 10 7 1.2 × 10 2 III RGD/GLS AAV-A120 3.4 × 10 7 8.0 × 10 7 1.0 × 10 3 III AAV-A139 2.0 × 10 7 9.0 × 10 7 5.0 × 10 5 III AAV-A139BPV/GLS 1.4 × 10 8 9.0 × 10 7 6.8 × 10 5 III AAV-A139LH/GLS 1.2 × 10 8 8.0 × 10 7 3.3 × 10 5 III AAV-A161BPV/ALS 4.0 × 10 7 8.0 × 10 7 1.2 × 10 5 III AAV-A161BPV/LLA 1.4 × 10 6 7.5 × 10 5 5.9 × 10 2 III AAV-A161BPV/GLS 1.2 × 10 7 7.5 × 10 6 8.7 × 10 4 III AAV-A161LH/GLS 4.0 × 10 6 8.0 × 10 7 3.4 × 10 4 III AAV-A312 1.8 × 10 6 — 5.3 × 10 2 III AAV-N319 2.4 × 10 7 4.5 × 10 5 0.6 × 10 3 III AAV-A323-4C- (+) — — I RGD/GLS AAV-A339BPV (+) — — II AAV-A375BPV — — — I AAV-A441 — — — I AAV-A459 7.2 × 10 6 8.0 × 10 7 6.5 × 10 4 III AAV-A459BPV/GLS 5.6 × 10 7 4.5 × 10 6 2.2 × 10 5 III AAV-A459LH/GLS 3.2 × 10 6 4.5 × 10 5 — II AAV-A466 (+) 7.5 × 10 7 — II AAV-N472 — — — I AAV-A480-4C- — — — I RGD/GLS AAV-N496 22 × 10 6 — 1.1 × 10 2 III AAV-A520LH/GLS (+) 7.5 × 10 7 — II AAV-A520BPV/LLA (+) 7.5 × 10 7 — II AAV-N540 (+) 8.0 × 10 7 — II AAV-N549 (+) 4.5 × 10 6 — II AAV-N584 1.1 × 10 8 8.0 × 10 7 4.0 × 10 5 III AAV-A584BPV/ALS 3.0 × 10 7 8.0 × 10 7 6.5 × 10 2 III AAV-A584BPV/LLA 1.3 × 10 7 9.0 × 10 6 — II AAV-A584BPV/GLS (+) 7.5 × 10 5 — II AAV-A587BPV/ALS 1.8 × 10 7 8.0 × 10 6 5.0 ×10 1 III AAV-A587BPV/LLA 7.2 × 10 5 9.0 × 10 5 — II AAV-A587BPV/GLS 3.5 × 10 7 9.0 × 10 7 2.7 × 10 2 III AAV-A595-4C- — 2.5 × 10 4 — I RGD/GLS AAV-A597-4C- — 2.5 × 10 4 — I RGD/GLS AAV-A657 1.8 × 10 7 7.5 × 10 7 5.2 × 10 4 III AAV (wild-type) 4.8 × 10 7 9.0 × 10 7 6.2 × 10 5 N/A
[0030] Of the sites chosen for linker insertion, 20 (80%) tolerated this manipulation as assessed by particle formation. Infectious virus could be produced containing linker insertions at twelve of the sites that were tolerated for viral assembly (12/20; 60%). This represents 48% of the sites originally selected for mutagenesis.
[0031] Although twelve sites within the AAV2 capsid protein(s) could be altered, and the mutant capsid monomers still assemble, package viral genomes, and infect cells, the infectious titers of these viruses varied greatly. These ranged from essentially wild-type levels to greater than four orders of magnitude less infectious than wild-type. Significantly, several sites could tolerate a wide range of genetic insertions without effects on virus titer. Both of the sites within the VP1/VP2 unique region of the capsid ORF proved able to tolerate genetic insertions without a loss in viral titer. See results for mutant vectors with insertions after amino acid positions A139 and A161. However, insertion after position A161 showed some dependence on surrounding sequence elements. See Example 5 below. Within the VP3 region of the capsid ORF, results were more variable. Although many insertions were tolerated with essentially no loss in vector titer (for example, after positions R459 and Q584), there was a greater dependence on linker sequences (compare AAV-N584BPV/ALS to AAV-N584BPV/LLA; also see Example 5, below) and the primary sequence of the epitope being inserted (compare AAV-A459BPV/GLS to AAV-A459LH/GLS).
EXAMPLE 2
[0032] The surface accessibility of inserted BPV epitopes in the mutant AAV vectors described in Example 1 was examined by immunoprecipitation.
[0033] Iodixanol grandient-purified vectors were precipitated with anti-BPV monoclonal antibody using protein-G Sepharose, subjected to SDS-PAGE, blotted to nylon membranes and probed with anti-AAV B1 monoclonal antibody. A summary of epitope display for each BPV insertion mutant is shown in Table 3 below.
TABLE 3 Surface Display of Inserted BPV Epitopes Mutant Vector Designation Epitope Display AAV-A139BPV/GLS + AAV-A161BPV/ALS + AAV-A161BPV/LLA + AAV-A161BPV/GLS + AAV-A339BPV − AAV-A459BPV/GLS + AAV-A520BPV/LLA + AAV-A584BPV/ALS + AAV-A584BPV/LLA + AAV-A584BPV/GLS − AAV-A587BPV/ALS + AAV-A587BPV/LLA − AAV-A587BPV/GLS +
[0034] Inserted peptide epitopes could be displayed efficiently on the surface of viral particles at each site tested which were all sites that insertion gave rise to infectious vectors. However, display was often dependent on inclusion of appropriate linker/scaffolding sequences.
EXAMPLE 3
[0035] The mutant AAV vectors of Example 1 were also tested for retention of the ability to bind HSPG.
[0036] The ability of the AAV vectors to bind HSPG was assessed by purifying the AAV preparations on an iodixanol gradient. The 40% iodixanol layer was collected and diluted in PBS-MK containing heparin sulfate affinity resin. The mixtures were incubated for two hours with gentle shaking at 4° C. followed by centrifugation. The viral bound resin was washed three times with PBS-MK for ten minutes at room temperature and resuspended in loading buffer. The samples were then boiled and analyzed by Western blotting with monoclonal antibody B1 directed against the AAV2 VP3 capsid protein.. A summary of the HS-binding characteristic for all of the mutant is presented in Table 4 below.
TABLE 4 HSPG Binding Mutant Vector Designation HSPG Binding AAV-A26 − AAV-A46 + AAV-A115-4C-RGD/GLS + AAV-A139 + AAV-A139BPV/GLS + AAV-A139LH/GLS + AAV-A161BPV/ALS + AAV-A161LH/GLS + AAV-A312 − AAV-A323-4C-RGD/GLS − AAV-A375BPV + AAV-A459 + AAV-A459LH/GLS + AAV-A466 + AAV-N472 + AAV-A480-4C-RGD/GLS + AAV-A520LH/GLS − AAV-A520BPV/LLA − AAV-A540 + AAV-N549 − AAV-A584BPV/ALS + AAV-A584BPV/LLA + AAV-A584BPV/GLS − AAV-A587BPV/ALS + AAV-A587BPV/LLA + AAV-A587BPV/GLS + AAV-A595-4C-RGD/GLS + AAV-A597-4C-RGD/GLS + AAV (wild-type) +
[0037] Some of the Type II mutants may have been non-infectious because they no longer bound HSPG (see the A26 or A520 mutants). These mutants are valuable because the endogenous tropism of the virus has been ablated and any binding capability added to the virus would be exclusive. In situations in which loss of receptor-binding ability as a result of introducing mutations at a specific capsid site is not desirable, the foregoing data demonstrates that binding can often be rescued by inclusion of appropriate flexible linker sequences.
EXAMPLE 4
[0038] A mutant AAV2 vectors containing a peptide insertion at two different sites within the capsid protein was generated using the methods described herein. The 4C-RGD peptide (SEQ ID NO: 10) was inserted using site directed mutagenesis as described in Example I after amino acid position 520 and position 588 within the VP3 capsid protein. The double mutant AAV2 vector (denoted herein as A520RGD4C588RGD4C) was assessed for particle formation and vector infectivity. Particles were identified by ELISA using A20 monoclonal antibody, whereas DNA-containing particles were identified by dot-blot. Vector particles were tested for infectivity by cellular tranduction assay on Adenovirus-infected C12 cells. The double mutant was able to infect cells and produce viral particles at a similar rate as other mutant and wild-type vectors. In Table 5, infectivity is presented as the percentage of target cells expressing the vector-encoded transgene and particle titer is presented as particles/μl.
TABLE 5 HS Particle Titer Capsid Infectivity Binding A20 ELISA DNA Dot Blot A520RGD4C − − 7.5 × 10 4 − A588RGD4C 52.1% + 7 × 10 5 8 × 10 4 A520RGD4C588RGD4C 45.8% − 2 × 10 5 5 × 10 4 ACG 49.9% + 1 × 10 6 2 × 10 5
[0039] The ability of the double mutant AAV capsids to bind HSPG was assessed as describe in Example 3. The double mutant was unable to bind to HSPG like the A520RGD4C vector, but retained the ability to infect the target cells similar to A5884RGD4C. See Table 9 above. Thus, the double mutant, A520RGD4C588RGD4C, is a receptor-targeted mutant that was produced at a reasonable titer and is defective in binding the AAV2 endogenous receptor HSPG.
EXAMPLE 5
[0040] It was envisioned that insertion of larger peptide epitopes might disrupt the AAV capsid by conformationally straining neighboring sequences. To circumvent this problem, two different approaches were employed in generating various mutant AAV packaging plasmids described in Example 1. First, in some altered capsids the structure of neighboring capsid regions was maintained by the introduction of a disulfide bond, and second, in other altered capsids flexible linker sequences were included to minimize conformational stress. See Table 6 below, wherein linker sequence TG-ALS indicates that linker amino acids TG were included at the amino terminus of the inserted epitope and amino acids ALS were included at the carboxy terminus of the inserted epitope.
TABLE 6 Dependence on Appropriate Linker/Scaffolding Sequences Mutant Vector Linker Particle Infectious HSPG Epitope Designation Sequence Titer Titer Binding Display Type AAV- TG-ALS ++++ ++++ + + III A161BPV/ALS (SEQ ID NO: 7) AAV- TG-LLA ++ ++ + + III A161BPV/LLA (SEQ ID NO: 8) AAV- TG-GLS +++ ++++ + + III A161BPV/GLS (SEQ ID NO: 9) AAV- TG-ALS ++++ ++++ + + III N584BPV/ALS (SEQ ID NO: 7) AAV- TG-LLA +++ − + + II N584BPV/LLA (SEQ ID NO: 8) AAV- TG-GLS + − − − II N584BPV/GLS (SEQ ID NO: 9) AAV- TG-ALS +++ +++ + + III A587BPV/ALS (SEQ ID NO: 7) AAV- TG-LLA ++ − + − II A587BPV/LLA (SEQ ID NO: 8) AAV- TG-GLS ++++ ++ + + III A587BPV/GLS (SEQ ID NO: 9)
[0041] Through the choice of appropriate linkers, infectious virus was rescued from previously dead mutants. In other instances, titers were influenced over several orders of magnitude. From this analysis it is clear that incorporation of flexible linkers containing small uncharged amino acids (such as alanine or serine) is extremely important for rescuing virus structure, infectivity, and for efficient epitope display.
EXAMPLE 6
[0042] The ability of vector AAV-A139LH (containing the LH receptor binding peptide) to target the human ovarian cancer cell line OVCAR-3 was tested. Expression of the LH receptor is upregulated on these cells. Because OVCAR-3 cells also express HSPG control experiments were performed to demonstrate that the AAV vector indeed exhibited an altered tropism.
[0043] Briefly, equal numbers of AAV-A139LH vector particles or vector particles with BPV inserts instead of LH inserts were applied to the surface of OVCAR-3 cells for 2 hours at 4° C. HeLa cells which express HSPG but not the LH receptor were used as a control cell line. Experiments were performed either in the presence or absence of 500 μg/ml soluble heparin sulfate (HS) which competes with binding between AAV and HSPG and in the presence or absence of progesterone which increases expression of the LH receptor. The cells were then washed of unbound vector, shifted to 37° C. and maintained for 48 hours at which time gene transfer was assessed.
[0044] In the experiments, AAV-A139LH transduced both HeLa and OVCAR-3 cells in the absence of HS. In the presence of HS, transduction of OVCAR-3 cells was reduced more than 10-fold and transduction of Hela cells was reduced more than 100-fold. Addition of progesterone restored transduction of ovarian cells that was lost in the presence of HS. The addition of progesterone increased transduction of OVCAR-3 cells by AAV-A139LH but not by AAV-A139BPV.
[0045] These results demonstrate that AAV-A139LH has acquired tropism for cells expressing the LH receptor.
[0046] As demonstrated by the foregoing data, AAV vectors of the invention may therefore be used for targeted DNA delivery. Some indications include: cancer gene therapy (e.g., for toxin or “suicide” gene delivery) and therapeutic gene transfer to cell and/or tissue types that have been refractive to gene transfer with conventional AAV vectors (e.g., airway epithelium for the treatment of cystic fibrosis, glia for the treatment of primary brain cancers, and hematopoietic progenitors cells for the treatment of any number of other disorders). For therapeutic gene delivery, AAV vectors of the invention may be targeted to non-antigen presenting cells in order to avoid an immune response to a gene or protein of interest and/or may incorporate epitope shielding moieties and/or mutations of immunodominant epitopes.
[0047] Alternatively, AAV vectors may be used as vaccines. Viral particles containing foreign epitopes may be used directly as immunogns. AAV vectors displaying such epitopes may also contain DNA that would lead to the expression of the same or related sequences within target cells. Such a dual immunization approach is contemplated to generate a more robust and wider range response. For vaccine use, targeted AAV vectors may specifically transduce APC (while avoiding other cells).
[0048] Finally, AAV vectors of the invention may be used as non-therapeutic reagents such as imaging reagents for the determination of vector pharmokinetics and biodistribution, for example, through the attachment of radio tracer elements and real-time scintography.
EXAMPLE 7
[0049] Fourteen additional AAV capsid mutants were generated in the non-infectious AAV plasmid, pACG, by PCR-based site-directed mutagenesis as described in Example 1. In all thirteen, the 4C-RGD peptide (CDCRGDCFC; SEQ ID NO: 10) was inserted into the AAV capsid monomer.
[0050] 4C-RGD encoding oligonucleotide were inserted into seven different sites within the AAV capsid gene. One site was within the VP1 unique region of the AAV2 capsid protein gene, three were within the VP1/VP2 unique region, and the three remaining sites were located within the VP3 region of the capsid ORF. DNA encoding the 4C-RGD peptide epitope was either inserted alone or flanked by one of two different five amino acid connecting peptide linkers, as described in Example 5. See Table 7 below. Producer cell lines based on 293 cells were used to generate modified AAV vectors comprising the altered capsids. These modified vectors are denoted as “AAV-RGD” collectively herein.
TABLE 7 Inserted Peptide Particle Vector Upstream (SEQ ID NO: Downstream Titer Designation Linker 10) Linker (ELISA) A46-RGD4C TG CDCRGDCFC — 8.5 × 10 7 A46-RGD4CGLS TG CDCRGDCFC GLS 4.5 × 10 6 A115-RGD4C TG CDCRGDCFC — 4.5 × 10 6 A115- TG CDCRGDCFC GLS 6.0 × 10 7 RGD4CGLS A139-RGD4C TG CDCRGDCFC — 8.5 × 10 7 A139- TG CDCRGDCFC GLS 9.0 × 10 7 RGD4CGLS A161-RGD4C TG CDCRGDCFC — 4.5 × 10 6 A161- TG CDCRGDCFC ALS 5.0 × 10 6 RGD4CALS A459-RGD4C TG CDCRGDCFC — 4.5 × 10 6 A459- TG CDCRGDCFC GLS 4.5 × 10 6 RGD4CGLS A584-RGD4C TG CDCRGDCFC — 8.5 × 10 7 A584- TG CDCRGDCFC ALS 9.0 × 10 7 RGD4CALS A588-RGD4C TG CDCRGDCFC — 9.0 × 10 7 A588- TG CDCRGDCFC GLS 9.0 × 10 7 RGD4CGLS Wild-type — — — 7.5 × 10 7
[0051] All the mutant capsid proteins were efficiently assembled and packaged. Furthermore, all of the modified AAV vectors generated were infectious, although there were significant differences in their efficiency of mediating gene transduction. See Table 8 below.
TABLE 8 Percent eGFP Positive Cells rAVVeGFP (+500 μg/ml Capsid rAVVeGFP (alone) Heparin Sulfate) A46-RGD4C 2.5% 1% A46-RGD4CGLS 3.% 0.5% A115-RGD4C 5% 1% A115-RGD4CGLS 7.5% 1% A139-RGD4C 35% 2.5% A139-RGD4CGLS 40% 2% A161-RGD4C 4% 0.5% A161-RGD4CALS 5% 1% A459-RGD4C 3.5% 1% A459-RGD4CGLS 3% 0.25% A584-RGD4C 49% 30% A584-RGD4CALS 51% 37% A588-RGD4C 40% 32% A588-RGD4CGLS 46% 38% Wild-type 47.5% 1%
[0052] The differences in gene transduction among the AAV-RGD vectors were related to both the site of peptide insertion and the presence, or absence, of linker sequences flanking the inserted 4C-RGD peptide. Insertion of the RGD epitope following AAV VP1 amino acids at positions 46, 115, 161 or 459 severely diminished infectious titer. However, insertions following the AAV amino acids at positions 139, 584 and 588 were well tolerated and did not affect titer appreciably.
[0053] For all the AAV-RGD vectors, inclusion of linker/scaffolding sequences resulted in slightly more efficient infection and maintenance of titer. To determine if the inserted 4C-RGD peptide had imparted to the modified vectors HSPG-independence, gene transduction assays were performed in the presence of heparin sulfate as described in Example 5. Although, AAV vectors containing unmodified capsids were unable to transduce cells in the presence of heparin sulfate, AAV-RGD vectors containing the 4C-RGD epitope following amino acids 584 and 588 transduced all types of cells tested in the presence of heparin sulfate. These results strongly suggest that AAV-RGD vectors set out in Table 6 are infecting cells via a HSPG-independent mechanism..
EXAMPLE 8
[0054] To assess if the AAV-RGD viral particles bind integrin receptors, a solid-phase ELISA assay using purified α v β 3 integrin was carried out as follows.
[0055] Neutravidin-coated plates (Pierce, Rockford, Ill.) were incubated with 1 μg/well of biotinylated heparin in PBST (0.05% Tween 20, 0.2% BSA) overnight at 4° C. The wells were then washed five times with wash buffer (PBS containing 0.05% Tween-20 and 0.1 % BSA) and AAV particles were bound at room temperature for two hours with gentle shaking. Subsequently, the plate was washed five times with wash buffer and purified integrin α v β 3 (Chemicon, Temecula, Calif.) in binding buffer (20 mM Tris-HCl , 150 mM NaCl , 2 mM CaCl 2 . 1 mM MgCl 2 . 1 mM MnCl 2 and 0.1% BSA, pH 7.5) was added to each well at a concentration of 1 μg/ml. The plates were incubated overnight at 4° C, washed three times with wash buffer and incubated with VNR139 monoclonal antibody (anti-α v subunit, GIBCO-BRL; Gaithersburg, Md.) in binding buffer for 2 hours at room temperature. The plates are then washed five times and incubated with secondary antibody (HRP-conjugated anti-mouse IgG) for 1 hour at room temperature. Following a final wash the ELISA plate was developed with ABTS substrate solution and the VECTASTAIN kit (Vector Laboratories, Burlingame, Calif.) as recommended by the manufacturer. Color development was stopped by the addition of 1N H 2 SO 4 , and plates were read in a plate reader set at 405 nM.
[0056] This analysis clearly indicated that the AAV-RGD viral particles bound α v β 3 integrin. The unmodified viral particles bound only at background level at all concentrations tested.
EXAMPLE 9
[0057] The insertion of the RGD peptide in the capsid protein of AAV-RGD vectors modified the cellular tropism of these vectors. The cell entry pathway of the AAV RGD vectors was investigated by measuring gene transfer to cell lines expressing various levels of HSPG as well as intergrins α v β 3 and α v β 5 . The following cell lines were tested: Hela cells, K562 human chronic myelogenous leukemia cells and Raji human lymphoblast-like cells.
[0058] First, flow cytometry was used to analyze the integrin and HSPG expression profile of these cell lines. Briefly, the cells were resuspended in SM buffer (HEPES-buffered saline containing 1% bovine serum albumin) at 2×10 6 cell/ml. The cells were incubated briefly at 37° C. to allow regeneration of surface integrins, then incubated with FITC-labeled LM609 antibody or FITC-labeled PIF6 antibody (1:200 dilution, Chemicon, Temeula, Calif.) for two hours at 4° C. HSPG expression in these cells was analyzed with anti-HSPG monoclonal antibody, HepSS-1 (1:200 dilution) for two hours at 4° C. Subsequently the cells were washed five times with SM buffer and incubated with FITC labeled goat anti-mouse IgM serum (1:800 dilution) for one hour at 4° C, the cells were washed with SM buffer and analyzed by flow cytometry. This analysis demonstrated that Hela cells expressed high levels of HSPG and α v β 5 integrin and low levels of α v β 3 integrin. K562 cells expressed low levels of HSPG, but α v β 5 integrin was expressed at high levels. Raji cells were negative for HSPG expression and expressed high levels of α v β 3 and α v β 5 integrins. Subsequently, the ability of the wild-type AAV-eGFP and the modified vectors (A584-RGD4C-eGFP, A584-RGD4CALS-eGFP, A588-RGD4C-eGFP, A588-RGD4CGLS) to transfer the eGFP gene to Hela, Raji and K562 cells was analyzed. The cells were seeded in a 24-well plates the day prior to infection in order to reach 75% confluence or about 5×10 5 cell/ml on the following day. Serial dilutions of the vectors were added to the cells in the presence of Ad5 at the MOI of 3iu/cell. The cells and viruses were incubated at 37° C. for 48 hours, after which the media was removed and the cells washed two time with PBS. The cells were then fixed and analyzed for GFP transduction by FACS analysis using an anti-GFP antibody.
[0059] Due to the low expression of HSPG, K562 and Raji cells were poorly transduced by AAVeGFP vectors containing unmodified AAV capsid protein, but these cells were efficiently transduced by the same vector packaged into A5884C-RGD capsids. The efficiency of eGFP gene transduction by the A5884C-RGD vector was similar to that observed by the unmodified AAV vector in Hela cells. Furthermore, gene transfer mediated by the RGD-containing particles was 4-fold higher in the K562 cells and 13-fold higher in the Raji cells as compared to transduction by vectors comprising unmodified capsids. These experiments clearly demonstrate that incorporation of the 4C-RGD epitope into the VP3 monomer of AAV2 vectors resulted in dramatic changes in the initial steps of virus-cell interaction, presumably by creating an alternative cell attachment and entry pathway.
[0060] Experiments were also carried out to compare the binding profiles of the wild type AAV2 vector and that containing the 4C-RGD capsid protein using soluble heparin sulfate to compete for binding, and anti-AAV monoclonal antibody A20 and FACS analysis to detect binding. In these experiments, wild type AAV2 vector did not bind to Hela cells in the presence of heparin sulfate. However, vectors containing A5884C-RGD capsid protein bound to Hela cells in the presence of soluble heparin sulfate. Binding of modified AAV viral particles to Hela cells was blocked by treatment with synthetic RGD peptide. Since the RGD peptides could efficiently block binding, these data further suggest that AAV-RGD capsids use cellular integrins as receptors during the cell attachment process.
EXAMPLE 10
[0061] Experiments were carried out to determine if the AAV-RGD vectors were capable of mediating gene delivery via integrin receptors.
[0062] Competitive inhibition assays using soluble heparin sulfate to inhibit AAV-mediated gene delivery were carried out as follows. AAV-RGD vectors or control vector AAVeGFP and modified vectors A584-RGD4C-eGFP, A584-RGD4CALS-eGFP, A588-RGD4C-eGFP, A588-RGD4CGLS were first incubated with 1500 μg/ml soluble heparin sulfate for two hours at 37° C. and then incubated with the Hela cells at 4° C. in the presence of 500 μg/ml heparin sulfate for an additional four hours. The cells were subsequently washed three times with fresh medium to remove unbound vector and incubated for 48 hours at 37° C., after which the cells were washed two times with PBS, fixed and analyzed for GFP gene transduction by FACS analysis in Hela cells.
[0063] When infected with the control virus, AAVeGFP comprising the unmodified capsid, GFP gene expression in Hela cells was efficiently blocked by soluble heparin sulfate. The same concentrations of heparin sulfate only blocked about 20% of A5884C-RGD capsid-mediated GFP expression in Hela cells. These experiments further demonstrated that the A5884-RGD capsids were capable of using an alternative HSPG-independent cell entry pathway.
[0064] To assess the specificity of the alternate cell entry pathway through integrin receptor, synthetic RGD peptide (200 μg/ml) or anti-integrin antibody VNR139 was used to determine if AAV-RGD mediated gene-transduction was inhibited in the presence of soluble heparin sulfate. The addition of the RGD specific inhibitor in combination with heparin sulfate completely inhibited A5884C-RGD-mediated gene expression. This experiment demonstrated that the HSPG-independent interaction was due to interaction with RGD-binding integrins expressed on the Hela cells.
EXAMPLE 11
[0065] The ability of unmodified AAV vector (wild type) to mediate GFP gene transductlon was tested in various ovarian adenocarcinoma cell lines. Transduction of the eGFP gene was measured by FACS. Unmodified AAV vector mediated gene transfer and expression in the human ovarian adenocarcinoma cell lines PA-1, OVCAR-3, OVCAR-3N and OV4. Unmodified AAV vector did not transduce the ovarian adenocarcinoma cell lines Hey, SKOV-3 and OV3. The unmodified AAV vector transfers the eGFP gene via the HSPG receptor. HSPG expression in ovarian cancer cells was determined by FACS analysis using an anti-HSGP antibody (Seikagaku America, Falmouth, Mass.). The unmodified AAV vector was unable to transduce the Hey and OV3 cell line since these cell lines were negative for HSPG expression. See Table 8 .
[0066] Since some human ovarian adenocarcinoma cell lines do not express HSPG, it was of interest to determine if ovarian tumor antigens (e.g., integrin) would facilitate AAV-mediated gene transfer in ovarian cancer cells. Integrin expression was analyzed by FACS analysis using an anti-α v antibody and the data is displayed in Table 9. All ovarian cancer cells tested expressed a member of the α v integrin family.
TABLE 9 Integrin and HSPG Expression on Human Ovarian Adenocarcinoma Ovarian Adenocarcinoma HSPG Expression α, Integrin Expression PA-1 + + Hey − + OVCAR-3 + + OVCAR-3N + + OV4 + + SKOV-3ip − + OV3 − +
[0067] The AAV-RGD vectors A588-RGD4C-eGFP and A588-RGD4CGLS were tested for their ability to target gene transfer to the ovarian cell lines as described in Example 9. These AAV-RGD vectors were able to transduce all ovarian cancer cell lines tested. The AAV-RGD vectors were able to more efficiently direct gene transfer in the ovarian cell lines PA-1, Hey, OVCAR-3, OVCAR-3N, OV4, SKOV-3ip and OV3 in comparison compared to wild-type AAV vector containing unmodified capsid.
[0068] AAV-RGD mediated gene transfer was demonstrated to be independent of HSPG interaction. Competitive gene transfer experiments in the OVCAR-3 cell line were carried out with soluble heparin sulfate as described in Example 10. A5884C-RGD vector efficiently directed gene transfer in the presence of soluble heparin sulfate in OVCAR-3 cells. However, gene transfer was completely blocked by the addition of RGD peptide or anti-integrin antibody in the presence of soluble heparin sulfate. The A5884C-RGD mediated gene transfer proceeded through integrin receptors.
EXAMPLE 12
[0069] Side-by-side comparison of the effectiveness of the unmodi fied AAV2 vector and the RGD-AAV vector for gene transfer to ovarian tumors was carried out in vivo. Human SKOV-3 cells were delivered intraperitoneally into SKID mice and developed tumors in the peritoneal cavity five days after implantation. The tumors were allowed to develop for five-seven days. Subsequently, matched doses of AAV-RGD vector or unmodified AAV vectors engineered to express the eGFP gene were administered intraperitoneally to the mice at 5×10 8 particles/mouse. At 15, 25, and 35 days post vector administration, the mice were sacrificed and the tumors were analyzed for the extent of gene delivery and expression. eGFP expression was detected in paraffin sections of tumor tissue using an anti-GFP antibody. In Table 10, GFP gene expression is indicated as a percent of tumor tissue expressing the gene, AAV-RGD indicates tumor tissue harvested from mice treated with AAV-RGD vector and ACG indicates tumor tissue harvested from mice treated with wild type vector.
TABLE 10 GFP Expression Day AAV-RGD ACG 15 15% 3% 25 60% 7% 35 95% 7%
[0070] It is generally accepted that for an anti-tumor gene therapy to be effective a genetic vector must be able to deliver and express a gene in as much of the tumor as possible. In studies with other transgenes, (e.g., HSV-TK) it has been established that at least 10-15% of the tumor needs to be transduced in order to be effective. This experiment suggest that the unmodified AAV2-vectors would not be effective anti-tumor agents since the transduction rate in vivo was low. In contrast, the modified RGD-AAV vector had a high rate of gene transduction and therefore may an excellent candidate for anti-tumor therapy. The fact that the eGFP expression comes on slowly (increasing over a 5 week period) is not unexpected and is a characteristic of rAAV.
EXAMPLE 13
[0071] In addition to inserting peptide ligands into the AAV2 vector to modify viral tropism, peptide insertions in the AAV2 vector can also be used as substrates for an enzymatic reaction covalently linking a biotin molecule in a site-specific manner to the AAV capsid. AAV capsids have been engineered to include a unique fifteen amino acid long biotin acceptor (BAP) peptide that is recognized by an E. coli enzyme, biotin protein ligase. In the presence of ATP, the ligase specifically attaches biotin to the lysine residue in this sequence. When the bacterial enzyme was expressed in a packaging cell line where AAV vector biosynthesis was occurring, vector capsid proteins were biotinylated as they were made and assembled into viral particles. The result of such a packaging scheme was in vivo biotinylated AAV particles. The advantages to labeling the AAV vector by biotinylation is that the reaction is enzymatic and therefore the conditions are gentle and the labeling is highly specific.
[0072] The AAV-BAP vectors were generated by methods similar to those described for the AAV-BPV, AAV-LH and AAV-RGD vectors in Example 1. Six AAV-mutants were generated and the packaging plasmids encoding these mutants are designated herein as pAB139BAP/ALS, pAB139BAP/GLS, pAB161BAP/ALS, pAB161BAP/GLS, pAB584BAP/GLS, and pAB584BAP/ALS. These mutants contain BAP insertions of the peptide sequence (GLNDIFEAQKIEWHE; SEQ ID NO: 11) flanked by either TG-ALS, or TG-GLS linker sequence (SEQ ID NO: 7 and 9, respectively). BAP insertions within the AAV vector following amino acids at positions 139 and 161 (regardless of the linker sequence) produced infectious mutant AAV vector particles at a level similar to wild-type. Insertion of the BAP peptide following amino acid 584 with the GLS linker causes a slight, but insignificant (less than 10-fold), decease in particle titer. Insertion of the BAP peptide at the same site within the AAV vector with the ALS linker caused a significant (>10,00 fold) decrease particle titer. All of the insertion sites within the AAV vector contemplated by the present invention (positions 139 and 161 in the VP1/VP2 region and positions 459, 584, 588 and 657) are candidate sites for the BAP insertion.
EXAMPLE 14
[0073] In order to label the AAV particles containing the BAP insert with biotin, a system for expressing the biotin ligase (BirA) enzyme in a packaging cell line was developed to create an in vivo biotinylated AAV vector. The BirA gene was inserted into the pCMV plasmid and is designated herein as pCMV-BirA. This plasmid was used to direct BirA gene expression in 283 cells and used with the AAV-BAP vector to produce in vivo biotinylated AAV vector. Briefly, 293 cells were transfected with the pCMV-BirA plasmid with a selectable maker gene (Neo). The resulting packaging cell was stably transfected with a rAAV comprising a DNA of interest flanked by AAV inverted terminal repeats, an AAV helper construct containing cap gene with a mutant BAP insertion (Example 12), an adenovirus helper plasmid or infected with adenovirus. Alternatively, 293 cells (which are standard AAV vector packaging cells) stably transfected with pCMV-BirA may be used as the packaging cell line. In addition, 293 cells infected with the adenovirus engineered to express the BirA gene may be used as the packaging cell line. AAV particles containing capsids with BAP insertions can also be labeled in vitro (post-purification) using purified BirA enzyme (available commercially).
[0074] Alternatively, a recombinant replication-competent adenovirus that expresses BirA was also developed for biotinylated AAV vector synthesis, eliminating the need for a separate BirA expression plasmid. This system allowed for large-scale AAV vector production of the biotinylated AAV utilizing packaging cell lines that have integrated copies of both AAV vector and AAV helper sequences. The Ad-based BirA expression system also was able to drive the expression of much larger amounts of the BirA gene product. The adenovirus expressed a BirA-eGFP fusion protein from a CMV promoter in the Ad E3 region, which allowed for monitoring BirA expression via GFP fluorescence.
[0075] A sensitive ELISA assay was used to quantitate the extent and efficiency of in vivo (and/or in vitro) biotinylation. AAV containing the 584BAP/GLS insertion was shown to be efficiently biotinylated in vivo (and in vitro) using either the plasmid based or Ad-based BirA expression systems. The biotinylated AAV vectors when conjugated to biotinylated ligands (e.g., monoclonal antibodies) via strepavidin can be specifically targeted to cell surface receptors of interest.
[0076] The advantages of using the biotinylation reaction to label the AAV viral particles is that it is an enzymatic reaction and therefore the conditions are gentle while the labeling is highly specific. In addition, the in vivo biotinylation reaction described herein has a much higher biotinylation efficiency than chemical biotinylation utilizing cross-linking reagents.
[0077] The biotinylated AAV viral particles are contemplated to serve as substrates for conjugation of targeting motifs(e.g., monoclonal antibodies, growth factors, cytokines) to the surface of vector particles through utilizing avidin/strepavidin-biotin chemistry. In addition, the biotinylated AAV viral particles are contemplated to be useful for visualizing the biodistribution of the viral particles both in vivo and in vitro. The biotinylated viral particles can be visualized with fluorescence or enzymatically with labeled strepavidin compounds. Biotinylation may also be useful for conjugating epitope shielding moieties, such as polyethylene glycol, to the AAV vector. The conjugation of shielding moieties will allow the vector to evade immune recognition. Biotinylation of the AAV vector is also contemplated to enhance intracellular trafficking of viral particles through conjugation of proteins or peptides such as nuclear transport proteins. Biotinylation may also be use to conjugate proteins or peptides which effect the processing of AAV vector genomes such as increasing the efficiency of integration. In addition, biotinylation may also be used to conjugate proteins or peptides that effect the target cells, e.g., proteins that make a target cell more susceptible to infection or proteins that activate a target cell thereby making it a better target for the expression of a therapeutic or antigenic peptide.
[0078] While the present invention has been described in terms of preferred embodiments, it understood that variations and improvements will occur to those skilled in the art. Therefore, only such limitations as appear in the claims should be placed on the invention.
1
18
1
14
PRT
Artificial Sequence
RGD Peptide
1
Thr Gly Cys Asp Cys Arg Gly Asp Cys Phe Cys Gly Leu Ser
1 5 10
2
11
PRT
Artificial Sequence
Bovine Papilloma Virus Peptide
2
Thr Gly Thr Pro Phe Tyr Leu Lys Gly Leu Ser
1 5 10
3
15
PRT
Artificial Sequence
Luteinizing hormone Peptide
3
Thr Gly His Cys Ser Thr Cys Tyr Tyr His Lys Ser Gly Leu Ser
1 5 10 15
4
11
PRT
Artificial Sequence
Bovine Papilloma Virus Peptide
4
Thr Gly Thr Pro Phe Tyr Leu Lys Ala Leu Ser
1 5 10
5
11
PRT
Artificial Sequence
Bovine Papilloma Virus Peptide
5
Thr Gly Thr Pro Phe Tyr Leu Lys Leu Leu Ala
1 5 10
6
8
PRT
Artificial Sequence
Bovine Papilloma Virus Peptide
6
Thr Gly Thr Pro Phe Tyr Leu Lys
1 5
7
5
PRT
Artificial Sequence
Synthetic Linker Peptide
7
Thr Gly Ala Leu Ser
1 5
8
5
PRT
Artificial Sequence
Synthetic Linker Peptide
8
Thr Gly Leu Leu Ala
1 5
9
5
PRT
Artificial Sequence
Synthetic Linker Peptide
9
Thr Gly Gly Leu Ser
1 5
10
9
PRT
Artificial Sequence
4C-RGD Peptide
10
Cys Asp Cys Arg Gly Asp Cys Phe Cys
1 5
11
15
PRT
Artificial Sequence
Biotin acceptor peptide
11
Gly Leu Asn Asp Ile Phe Glu Ala Gln Lys Ile Glu Trp His Glu
1 5 10 15
12
4679
DNA
adeno-associated virus 2
12
ttggccactc cctctctgcg cgctcgctcg ctcactgagg ccgggcgacc aaaggtcgcc 60
cgacgcccgg gctttgcccg ggcggcctca gtgagcgagc gagcgcgcag agagggagtg 120
gccaactcca tcactagggg ttcctggagg ggtggagtcg tgacgtgaat tacgtcatag 180
ggttagggag gtcctgtatt agaggtcacg tgagtgtttt gcgacatttt gcgacaccat 240
gtggtcacgc tgggtattta agcccgagtg agcacgcagg gtctccattt tgaagcggga 300
ggtttgaacg cgcagccgcc atgccggggt tttacgagat tgtgattaag gtccccagcg 360
accttgacga gcatctgccc ggcatttctg acagctttgt gaactgggtg gccgagaagg 420
aatgggagtt gccgccagat tctgacatgg atctgaatct gattgagcag gcacccctga 480
ccgtggccga gaagctgcag cgcgactttc tgacggaatg gcgccgtgtg agtaaggccc 540
cggaggccct tttctttgtg caatttgaga agggagagag ctacttccac atgcacgtgc 600
tcgtggaaac caccggggtg aaatccatgg ttttgggacg tttcctgagt cagattcgcg 660
aaaaactgat tcagagaatt taccgcggga tcgagccgac tttgccaaac tggttcgcgg 720
tcacaaagac cagaaatggc gccggaggcg ggaacaaggt ggtggatgag tgctacatcc 780
ccaattactt gctccccaaa acccagcctg agctccagtg ggcgtggact aatatggaac 840
agtatttaag cgcctgtttg aatctcacgg agcgtaaacg gttggtggcg cagcatctga 900
cgcacgtgtc gcagacgcag gagcagaaca aagagaatca gaatcccaat tctgatgcgc 960
cggtgatcag atcaaaaact tcagccaggt acatggagct ggtcgggtgg ctcgtggaca 1020
aggggattac ctcggagaag cagtggatcc aggaggacca ggcctcatac atctccttca 1080
atgcggcctc caactcgcgg tcccaaatca aggctgcctt ggacaatgcg ggaaagatta 1140
tgagcctgac taaaaccgcc cccgactacc tggtgggcca gcagcccgtg gaggacattt 1200
ccagcaatcg gatttataaa attttggaac taaacgggta cgatccccaa tatgcggctt 1260
ccgtctttct gggatgggcc acgaaaaagt tcggcaagag gaacaccatc tggctgtttg 1320
ggcctgcaac taccgggaag accaacatcg cggaggccat agcccacact gtgcccttct 1380
acgggtgcgt aaactggacc aatgagaact ttcccttcaa cgactgtgtc gacaagatgg 1440
tgatctggtg ggaggagggg aagatgaccg ccaaggtcgt ggagtcggcc aaagccattc 1500
tcggaggaag caaggtgcgc gtggaccaga aatgcaagtc ctcggcccag atagacccga 1560
ctcccgtgat cgtcacctcc aacaccaaca tgtgcgccgt gattgacggg aactcaacga 1620
ccttcgaaca ccagcagccg ttgcaagacc ggatgttcaa atttgaactc acccgccgtc 1680
tggatcatga ctttgggaag gtcaccaagc aggaagtcaa agactttttc cggtgggcaa 1740
aggatcacgt ggttgaggtg gagcatgaat tctacgtcaa aaagggtgga gccaagaaaa 1800
gacccgcccc cagtgacgca gatataagtg agcccaaacg ggtgcgcgag tcagttgcgc 1860
agccatcgac gtcagacgcg gaagcttcga tcaactacgc agacaggtac caaaacaaat 1920
gttctcgtca cgtgggcatg aatctgatgc tgtttccctg cagacaatgc gagagaatga 1980
atcagaattc aaatatctgc ttcactcacg gacagaaaga ctgtttagag tgctttcccg 2040
tgtcagaatc tcaacccgtt tctgtcgtca aaaaggcgta tcagaaactg tgctacattc 2100
atcatatcat gggaaaggtg ccagacgctt gcactgcctg cgatctggtc aatgtggatt 2160
tggatgactg catctttgaa caataaatga tttaaatcag gtatggctgc cgatggttat 2220
cttccagatt ggctcgagga cactctctct gaaggaataa gacagtggtg gaagctcaaa 2280
cctggcccac caccaccaaa gcccgcagag cggcataagg acgacagcag gggtcttgtg 2340
cttcctgggt acaagtacct cggacccttc aacggactcg acaagggaga gccggtcaac 2400
gaggcagacg ccgcggccct cgagcacgac aaagcctacg accggcagct cgacagcgga 2460
gacaacccgt acctcaagta caaccacgcc gacgcggagt ttcaggagcg ccttaaagaa 2520
gatacgtctt ttgggggcaa cctcggacga gcagtcttcc aggcgaaaaa gagggttctt 2580
gaacctctgg gcctggttga ggaacctgtt aagacggctc cgggaaaaaa gaggccggta 2640
gagcactctc ctgtggagcc agactcctcc tcgggaaccg gaaaggcggg ccagcagcct 2700
gcaagaaaaa gattgaattt tggtcagact ggagacgcag actcagtacc tgacccccag 2760
cctctcggac agccaccagc agccccctct ggtctgggaa ctaatacgat ggctacaggc 2820
agtggcgcac caatggcaga caataacgag ggcgccgacg gagtgggtaa ttcctcggga 2880
aattggcatt gcgattccac atggatgggc gacagagtca tcaccaccag cacccgaacc 2940
tgggccctgc ccacctacaa caaccacctc tacaaacaaa tttccagcca atcaggagcc 3000
tcgaacgaca atcactactt tggctacagc accccttggg ggtattttga cttcaacaga 3060
ttccactgcc acttttcacc acgtgactgg caaagactca tcaacaacaa ctggggattc 3120
cgacccaaga gactcaactt caagctcttt aacattcaag tcaaagaggt cacgcagaat 3180
gacggtacga cgacgattgc caataacctt accagcacgg ttcaggtgtt tactgactcg 3240
gagtaccagc tcccgtacgt cctcggctcg gcgcatcaag gatgcctccc gccgttccca 3300
gcagacgtct tcatggtgcc acagtatgga tacctcaccc tgaacaacgg gagtcaggca 3360
gtaggacgct cttcatttta ctgcctggag tactttcctt ctcagatgct gcgtaccgga 3420
aacaacttta ccttcagcta cacttttgag gacgttcctt tccacagcag ctacgctcac 3480
agccagagtc tggaccgtct catgaatcct ctcatcgacc agtacctgta ttacttgagc 3540
agaacaaaca ctccaagtgg aaccaccacg cagtcaaggc ttcagttttc tcaggccgga 3600
gcgagtgaca ttcgggacca gtctaggaac tggcttcctg gaccctgtta ccgccagcag 3660
cgagtatcaa agacatctgc ggataacaac aacagtgaat actcgtggac tggagctacc 3720
aagtaccacc tcaatggcag agactctctg gtgaatccgg gcccggccat ggcaagccac 3780
aaggacgatg aagaaaagtt ttttcctcag agcggggttc tcatctttgg gaagcaaggc 3840
tcagagaaaa caaatgtgga cattgaaaag gtcatgatta cagacgaaga ggaaatcagg 3900
acaaccaatc ccgtggctac ggagcagtat ggttctgtat ctaccaacct ccagagaggc 3960
aacagacaag cagctaccgc agatgtcaac acacaaggcg ttcttccagg catggtctgg 4020
caggacagag atgtgtacct tcaggggccc atctgggcaa agattccaca cacggacgga 4080
cattttcacc cctctcccct catgggtgga ttcggactta aacaccctcc tccacagatt 4140
ctcatcaaga acaccccggt acctgcgaat ccttcgacca ccttcagtgc ggcaaagttt 4200
gcttccttca tcacacagta ctccacggga caggtcagcg tggagatcga gtgggagctg 4260
cagaaggaaa acagcaaacg ctggaatccc gaaattcagt acacttccaa ctacaacaag 4320
tctgttaatg tggactttac tgtggacact aatggcgtgt attcagagcc tcgccccatt 4380
ggcaccagat acctgactcg taatctgtaa ttgcttgtta atcaataaac cgtttaattc 4440
gtttcagttg aactttggtc tctgcgtatt tctttcttat ctagtttcca tggctacgta 4500
gataagtagc atggcgggtt aatcattaac tacaaggaac ccctagtgat ggagttggcc 4560
actccctctc tgcgcgctcg ctcgctcact gaggccgggc gaccaaaggt cgcccgacgc 4620
ccgggctttg cccgggcggc ctcagtgagc gagcgagcgc gcagagaggg agtggccaa 4679
13
735
PRT
adeno-associated virus 2 VP1 caspid protien
13
Met Ala Ala Asp Gly Tyr Leu Pro Asp Trp Leu Glu Asp Thr Leu Ser
1 5 10 15
Glu Gly Ile Arg Gln Trp Trp Lys Leu Lys Pro Gly Pro Pro Pro Pro
20 25 30
Lys Pro Ala Glu Arg His Lys Asp Asp Ser Arg Gly Leu Val Leu Pro
35 40 45
Gly Tyr Lys Tyr Leu Gly Pro Phe Asn Gly Leu Asp Lys Gly Glu Pro
50 55 60
Val Asn Glu Ala Asp Ala Ala Ala Leu Glu His Asp Lys Ala Tyr Asp
65 70 75 80
Arg Gln Leu Asp Ser Gly Asp Asn Pro Tyr Leu Lys Tyr Asn His Ala
85 90 95
Asp Ala Glu Phe Gln Glu Arg Leu Lys Glu Asp Thr Ser Phe Gly Gly
100 105 110
Asn Leu Gly Arg Ala Val Phe Gln Ala Lys Lys Arg Val Leu Glu Pro
115 120 125
Leu Gly Leu Val Glu Glu Pro Val Lys Thr Ala Pro Gly Lys Lys Arg
130 135 140
Pro Val Glu His Ser Pro Val Glu Pro Asp Ser Ser Ser Gly Thr Gly
145 150 155 160
Lys Ala Gly Gln Gln Pro Ala Arg Lys Arg Leu Asn Phe Gly Gln Thr
165 170 175
Gly Asp Ala Asp Ser Val Pro Asp Pro Gln Pro Leu Gly Gln Pro Pro
180 185 190
Ala Ala Pro Ser Gly Leu Gly Thr Asn Thr Met Ala Thr Gly Ser Gly
195 200 205
Ala Pro Met Ala Asp Asn Asn Glu Gly Ala Asp Gly Val Gly Asn Ser
210 215 220
Ser Gly Asn Trp His Cys Asp Ser Thr Trp Met Gly Asp Arg Val Ile
225 230 235 240
Thr Thr Ser Thr Arg Thr Trp Ala Leu Pro Thr Tyr Asn Asn His Leu
245 250 255
Tyr Lys Gln Ile Ser Ser Gln Ser Gly Ala Ser Asn Asp Asn His Tyr
260 265 270
Phe Gly Tyr Ser Thr Pro Trp Gly Tyr Phe Asp Phe Asn Arg Phe His
275 280 285
Cys His Phe Ser Pro Arg Asp Trp Gln Arg Leu Ile Asn Asn Asn Trp
290 295 300
Gly Phe Arg Pro Lys Arg Leu Asn Phe Lys Leu Phe Asn Ile Gln Val
305 310 315 320
Lys Glu Val Thr Gln Asn Asp Gly Thr Thr Thr Ile Ala Asn Asn Leu
325 330 335
Thr Ser Thr Val Gln Val Phe Thr Asp Ser Glu Tyr Gln Leu Pro Tyr
340 345 350
Val Leu Gly Ser Ala His Gln Gly Cys Leu Pro Pro Phe Pro Ala Asp
355 360 365
Val Phe Met Val Pro Gln Tyr Gly Tyr Leu Thr Leu Asn Asn Gly Ser
370 375 380
Gln Ala Val Gly Arg Ser Ser Phe Tyr Cys Leu Glu Tyr Phe Pro Ser
385 390 395 400
Gln Met Leu Arg Thr Gly Asn Asn Phe Thr Phe Ser Tyr Thr Phe Glu
405 410 415
Asp Val Pro Phe His Ser Ser Tyr Ala His Ser Gln Ser Leu Asp Arg
420 425 430
Leu Met Asn Pro Leu Ile Asp Gln Tyr Leu Tyr Tyr Leu Ser Arg Thr
435 440 445
Asn Thr Pro Ser Gly Thr Thr Thr Gln Ser Arg Leu Gln Phe Ser Gln
450 455 460
Ala Gly Ala Ser Asp Ile Arg Asp Gln Ser Arg Asn Trp Leu Pro Gly
465 470 475 480
Pro Cys Tyr Arg Gln Gln Arg Val Ser Lys Thr Ser Ala Asp Asn Asn
485 490 495
Asn Ser Glu Tyr Ser Trp Thr Gly Ala Thr Lys Tyr His Leu Asn Gly
500 505 510
Arg Asp Ser Leu Val Asn Pro Gly Pro Ala Met Ala Ser His Lys Asp
515 520 525
Asp Glu Glu Lys Phe Phe Pro Gln Ser Gly Val Leu Ile Phe Gly Lys
530 535 540
Gln Gly Ser Glu Lys Thr Asn Val Asp Ile Glu Lys Val Met Ile Thr
545 550 555 560
Asp Glu Glu Glu Ile Arg Thr Thr Asn Pro Val Ala Thr Glu Gln Tyr
565 570 575
Gly Ser Val Ser Thr Asn Leu Gln Arg Gly Asn Arg Gln Ala Ala Thr
580 585 590
Ala Asp Val Asn Thr Gln Gly Val Leu Pro Gly Met Val Trp Gln Asp
595 600 605
Arg Asp Val Tyr Leu Gln Gly Pro Ile Trp Ala Lys Ile Pro His Thr
610 615 620
Asp Gly His Phe His Pro Ser Pro Leu Met Gly Gly Phe Gly Leu Lys
625 630 635 640
His Pro Pro Pro Gln Ile Leu Ile Lys Asn Thr Pro Val Pro Ala Asn
645 650 655
Pro Ser Thr Thr Phe Ser Ala Ala Lys Phe Ala Ser Phe Ile Thr Gln
660 665 670
Tyr Ser Thr Gly Gln Val Ser Val Glu Ile Glu Trp Glu Leu Gln Lys
675 680 685
Glu Asn Ser Lys Arg Trp Asn Pro Glu Ile Gln Tyr Thr Ser Asn Tyr
690 695 700
Asn Lys Ser Val Asn Val Asp Phe Thr Val Asp Thr Asn Gly Val Tyr
705 710 715 720
Ser Glu Pro Arg Pro Ile Gly Thr Arg Tyr Leu Thr Arg Asn Leu
725 730 735
14
598
PRT
adeno-associated virus 2 VP2 capsid protien
14
Met Ala Pro Gly Lys Lys Arg Pro Val Glu His Ser Pro Val Glu Pro
1 5 10 15
Asp Ser Ser Ser Gly Thr Gly Lys Ala Gly Gln Gln Pro Ala Arg Lys
20 25 30
Arg Leu Asn Phe Gly Gln Thr Gly Asp Ala Asp Ser Val Pro Asp Pro
35 40 45
Gln Pro Leu Gly Gln Pro Pro Ala Ala Pro Ser Gly Leu Gly Thr Asn
50 55 60
Thr Met Ala Thr Gly Ser Gly Ala Pro Met Ala Asp Asn Asn Glu Gly
65 70 75 80
Ala Asp Gly Val Gly Asn Ser Ser Gly Asn Trp His Cys Asp Ser Thr
85 90 95
Trp Met Gly Asp Arg Val Ile Thr Thr Ser Thr Arg Thr Trp Ala Leu
100 105 110
Pro Thr Tyr Asn Asn His Leu Tyr Lys Gln Ile Ser Ser Gln Ser Gly
115 120 125
Ala Ser Asn Asp Asn His Tyr Phe Gly Tyr Ser Thr Pro Trp Gly Tyr
130 135 140
Phe Asp Phe Asn Arg Phe His Cys His Phe Ser Pro Arg Asp Trp Gln
145 150 155 160
Arg Leu Ile Asn Asn Asn Trp Gly Phe Arg Pro Lys Arg Leu Asn Phe
165 170 175
Lys Leu Phe Asn Ile Gln Val Lys Glu Val Thr Gln Asn Asp Gly Thr
180 185 190
Thr Thr Ile Ala Asn Asn Leu Thr Ser Thr Val Gln Val Phe Thr Asp
195 200 205
Ser Glu Tyr Gln Leu Pro Tyr Val Leu Gly Ser Ala His Gln Gly Cys
210 215 220
Leu Pro Pro Phe Pro Ala Asp Val Phe Met Val Pro Gln Tyr Gly Tyr
225 230 235 240
Leu Thr Leu Asn Asn Gly Ser Gln Ala Val Gly Arg Ser Ser Phe Tyr
245 250 255
Cys Leu Glu Tyr Phe Pro Ser Gln Met Leu Arg Thr Gly Asn Asn Phe
260 265 270
Thr Phe Ser Tyr Thr Phe Glu Asp Val Pro Phe His Ser Ser Tyr Ala
275 280 285
His Ser Gln Ser Leu Asp Arg Leu Met Asn Pro Leu Ile Asp Gln Tyr
290 295 300
Leu Tyr Tyr Leu Ser Arg Thr Asn Thr Pro Ser Gly Thr Thr Thr Gln
305 310 315 320
Ser Arg Leu Gln Phe Ser Gln Ala Gly Ala Ser Asp Ile Arg Asp Gln
325 330 335
Ser Arg Asn Trp Leu Pro Gly Pro Cys Tyr Arg Gln Gln Arg Val Ser
340 345 350
Lys Thr Ser Ala Asp Asn Asn Asn Ser Glu Tyr Ser Trp Thr Gly Ala
355 360 365
Thr Lys Tyr His Leu Asn Gly Arg Asp Ser Leu Val Asn Pro Gly Pro
370 375 380
Ala Met Ala Ser His Lys Asp Asp Glu Glu Lys Phe Phe Pro Gln Ser
385 390 395 400
Gly Val Leu Ile Phe Gly Lys Gln Gly Ser Glu Lys Thr Asn Val Asp
405 410 415
Ile Glu Lys Val Met Ile Thr Asp Glu Glu Glu Ile Arg Thr Thr Asn
420 425 430
Pro Val Ala Thr Glu Gln Tyr Gly Ser Val Ser Thr Asn Leu Gln Arg
435 440 445
Gly Asn Arg Gln Ala Ala Thr Ala Asp Val Asn Thr Gln Gly Val Leu
450 455 460
Pro Gly Met Val Trp Gln Asp Arg Asp Val Tyr Leu Gln Gly Pro Ile
465 470 475 480
Trp Ala Lys Ile Pro His Thr Asp Gly His Phe His Pro Ser Pro Leu
485 490 495
Met Gly Gly Phe Gly Leu Lys His Pro Pro Pro Gln Ile Leu Ile Lys
500 505 510
Asn Thr Pro Val Pro Ala Asn Pro Ser Thr Thr Phe Ser Ala Ala Lys
515 520 525
Phe Ala Ser Phe Ile Thr Gln Tyr Ser Thr Gly Gln Val Ser Val Glu
530 535 540
Ile Glu Trp Glu Leu Gln Lys Glu Asn Ser Lys Arg Trp Asn Pro Glu
545 550 555 560
Ile Gln Tyr Thr Ser Asn Tyr Asn Lys Ser Val Asn Val Asp Phe Thr
565 570 575
Val Asp Thr Asn Gly Val Tyr Ser Glu Pro Arg Pro Ile Gly Thr Arg
580 585 590
Tyr Leu Thr Arg Asn Leu
595
15
533
PRT
adeno-associated virus 2 VP3 capsid protien
15
Met Ala Thr Gly Ser Gly Ala Pro Met Ala Asp Asn Asn Glu Gly Ala
1 5 10 15
Asp Gly Val Gly Asn Ser Ser Gly Asn Trp His Cys Asp Ser Thr Trp
20 25 30
Met Gly Asp Arg Val Ile Thr Thr Ser Thr Arg Thr Trp Ala Leu Pro
35 40 45
Thr Tyr Asn Asn His Leu Tyr Lys Gln Ile Ser Ser Gln Ser Gly Ala
50 55 60
Ser Asn Asp Asn His Tyr Phe Gly Tyr Ser Thr Pro Trp Gly Tyr Phe
65 70 75 80
Asp Phe Asn Arg Phe His Cys His Phe Ser Pro Arg Asp Trp Gln Arg
85 90 95
Leu Ile Asn Asn Asn Trp Gly Phe Arg Pro Lys Arg Leu Asn Phe Lys
100 105 110
Leu Phe Asn Ile Gln Val Lys Glu Val Thr Gln Asn Asp Gly Thr Thr
115 120 125
Thr Ile Ala Asn Asn Leu Thr Ser Thr Val Gln Val Phe Thr Asp Ser
130 135 140
Glu Tyr Gln Leu Pro Tyr Val Leu Gly Ser Ala His Gln Gly Cys Leu
145 150 155 160
Pro Pro Phe Pro Ala Asp Val Phe Met Val Pro Gln Tyr Gly Tyr Leu
165 170 175
Thr Leu Asn Asn Gly Ser Gln Ala Val Gly Arg Ser Ser Phe Tyr Cys
180 185 190
Leu Glu Tyr Phe Pro Ser Gln Met Leu Arg Thr Gly Asn Asn Phe Thr
195 200 205
Phe Ser Tyr Thr Phe Glu Asp Val Pro Phe His Ser Ser Tyr Ala His
210 215 220
Ser Gln Ser Leu Asp Arg Leu Met Asn Pro Leu Ile Asp Gln Tyr Leu
225 230 235 240
Tyr Tyr Leu Ser Arg Thr Asn Thr Pro Ser Gly Thr Thr Thr Gln Ser
245 250 255
Arg Leu Gln Phe Ser Gln Ala Gly Ala Ser Asp Ile Arg Asp Gln Ser
260 265 270
Arg Asn Trp Leu Pro Gly Pro Cys Tyr Arg Gln Gln Arg Val Ser Lys
275 280 285
Thr Ser Ala Asp Asn Asn Asn Ser Glu Tyr Ser Trp Thr Gly Ala Thr
290 295 300
Lys Tyr His Leu Asn Gly Arg Asp Ser Leu Val Asn Pro Gly Pro Ala
305 310 315 320
Met Ala Ser His Lys Asp Asp Glu Glu Lys Phe Phe Pro Gln Ser Gly
325 330 335
Val Leu Ile Phe Gly Lys Gln Gly Ser Glu Lys Thr Asn Val Asp Ile
340 345 350
Glu Lys Val Met Ile Thr Asp Glu Glu Glu Ile Arg Thr Thr Asn Pro
355 360 365
Val Ala Thr Glu Gln Tyr Gly Ser Val Ser Thr Asn Leu Gln Arg Gly
370 375 380
Asn Arg Gln Ala Ala Thr Ala Asp Val Asn Thr Gln Gly Val Leu Pro
385 390 395 400
Gly Met Val Trp Gln Asp Arg Asp Val Tyr Leu Gln Gly Pro Ile Trp
405 410 415
Ala Lys Ile Pro His Thr Asp Gly His Phe His Pro Ser Pro Leu Met
420 425 430
Gly Gly Phe Gly Leu Lys His Pro Pro Pro Gln Ile Leu Ile Lys Asn
435 440 445
Thr Pro Val Pro Ala Asn Pro Ser Thr Thr Phe Ser Ala Ala Lys Phe
450 455 460
Ala Ser Phe Ile Thr Gln Tyr Ser Thr Gly Gln Val Ser Val Glu Ile
465 470 475 480
Glu Trp Glu Leu Gln Lys Glu Asn Ser Lys Arg Trp Asn Pro Glu Ile
485 490 495
Gln Tyr Thr Ser Asn Tyr Asn Lys Ser Val Asn Val Asp Phe Thr Val
500 505 510
Asp Thr Asn Gly Val Tyr Ser Glu Pro Arg Pro Ile Gly Thr Arg Tyr
515 520 525
Leu Thr Arg Asn Leu
530
16
6
PRT
Artificial Sequence
Bovine Papilloma Virus peptide
16
Thr Pro Phe Tyr Leu Lys
1 5
17
10
PRT
Artificial Sequence
Luteinizing Hormone peptide
17
His Cys Ser Thr Cys Tyr Tyr His Lys Ser
1 5 10
18
5
PRT
Artificial Sequence
synthetic targeting peptide
18
Phe Val Phe Lys Pro
1 5 | The invention relates to Adeno-associated virus vectors. In particular, it relates to Adeno-associated virus vectors with modified capsid proteins and materials and methods for their preparation and use. | 2 |
RELATED APPLICATION
[0001] This application is a division of U.S. application Ser. No. 10/351,203, filed Jan. 24, 2003, and claims the benefit of U.S. Provisional Application Ser. No. 60/352,117 filed Jan. 24, 2002 entitled ANTI-EXPLOSIVE FERTILIZER COATINGS, the teachings of both of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is broadly concerned with a coating and methods of applying the coating to agricultural grade fertilizer particles. The coating inhibits the adsorption and absorption of hydrocarbons into the pores of the fertilizer particles thereby reducing the efficacy of the fertilizer as an oxidizing source in the production of incendiary devices. More particularly, the invention is concerned with coatings containing at least one polymer and methods of applying the coating to fertilizer products. The invention has particular utility in the deterrence or prevention of agricultural grade fertilizers and industrial grade ammonium nitrate being used to create weapons of terror.
[0004] 2. Description of the Prior Art
[0005] Some common agricultural grade fertilizers generally comprise compounds which serve as excellent oxidizing agents, ammonium nitrate being one such compound. Generally, the fertilizer particles contain pores into which a number of other chemical agents can infiltrate, including hydrocarbon materials. The combined ammonium nitrate/fuel infiltrated particle is commonly referred to as ANFO (ammonium nitrate fuel oil). The article “Blasting Products” of the ANFO Manual distributed by El Dorado Chemical Company (St. Louis, Mo.), a copy of which is submitted herewith, is hereby incorporated by reference. When supplied with an ignition source, the hydrocarbon material acts as a fuel that is oxidized by the fertilizer particles. The resulting chemical reaction can release considerable amounts of energy, especially when the reactants are present in substantial quantities. To be most effective as an explosive, the ANFO will comprise about 5.7% by weight fuel oil. It is understood that when alternative sources of hydrocarbon fuel are used the fuel:ammonium nitrate ratio may need to be altered to achieve a stoichiometrically balanced mixture.
[0006] Both hydrocarbon fuels and fertilizers are readily available and relatively inexpensive products thereby making them excellent raw materials for producing renegade incendiary devices. The Oklahoma City bombing incident is one tragic example of how such materials may be used to perpetrate large-scale, terrorist atrocities.
[0007] During the manufacturing process, fertilizer particles are coated with an anti-dusting agent in order to reduce the amount of fertilizer dust produced during handling of the particles. A commonly used anti-dusting agent is Galoryl (Lobeco Products Inc., Lobeco, S.C.) which is hydrocarbon based and is sprayed on during the manufacturing process. Being hydrocarbon based, this coating does not inhibit the infiltration of other hydrocarbon materials that may be used in constructing an incendiary device. Additionally, the anti-dusting agent does not form a protective barrier film encapsulating the entire fertilizer particle thereby leaving numerous pores exposed.
[0008] In order to prevent the misuse of ammonium nitrate in improvised explosives, it is necessary physically separate the fuel from the ammonium nitrate and also prevent the penetration of the liquid fuel into the fertilizer particles. If the fuel does not enter the interior of a sufficient number of particles in an optimal amount, the utility of ammonium nitrate particles as an oxidizer is substantially reduced or completely eliminated. There is a real need in the art for a fertilizer particle coating which forms a barrier that inhibits hydrocarbon infiltration of the fertilizer pores, and which will not alter the effectiveness of the fertilizer for its intended agricultural applications.
SUMMARY OF THE INVENTION
[0009] The present invention overcomes the problems outlined above and provides a coating for use with agricultural grade fertilizers and industrial grade ammonium nitrate. The coating should comprise a solution including at least one material which exhibits one or more of the following properties: substantially water soluble, substantially hydrocarbon insoluble, and capable of forming a film.
[0010] As used herein the term “substantially water soluble” means that the material may be contacted with water or a water-containing solvent mixture for a period of time up to approximately 24 hours and be transformed into a solution that contains at least 1% w/w of the material. The solution should be relatively stable meaning that the solute will not precipitate out of solution for at least about 3-4 hours. Various procedures may need to be employed to achieve this dissolution, such as heating and agitation. As used herein, the term “substantially hydrocarbon insoluble” means that the material will not dissolve in hydrocarbons to an extent greater than about 10% w/w upon exposure for a period of time up to approximately 48 hours at temperature and conditions of use.
[0011] With respect to simple conventional coating techniques, the pH of the solution may also play a role due to its effect on ammonia volatilization. Other coating techniques may reduce or eliminate the effect that pH has on ammonia volatilization. In preferred embodiments using the coating techniques which would have an effect on ammonia volatilization, the coating should have a pH of about 7.0 or less, preferably about 6.5 or less and more preferably about 5.5 or less. Those of ordinary skill in the art of coating will be able to use and develop coating methods which eliminate or reduce the volatilization of ammonia regardless of the pH of the coating. For example, spray drying or using a fluidized bed allow use of coatings with pH's above 7.0.
[0012] There is a wide range of materials which may be suitable for use in accordance with the present invention. Such materials include various natural and synthetic gums, starches and starch derivatives, polyethers, polysaccharides, polycarboxylates, poly-sulfonates, a wide range of monomers, polymers and copolymers, and combinations thereof. Among those materials for use with the invention are compositions that contain various mineral salts in addition to or instead of polymeric materials. Useful materials also include those that are known in the art of product formulation as flame and/or fire retardants. These include but are not limited to various boron-containing compositions such as borates, various metal salts including polymeric metal salts, oxides, carbides, nitrides, borides, silicates including polysilicates, silicides, aluminum-containing compositions, sulfates, phosphates, polyphosphates, chlorides, bromides, polymolybdates, molybdate salts, halogenated (particularly brominated) water-dispersible compounds with molecular weights above about 200 AMU. Ammonium phosphates are particularly preferred fire or flame retardant materials. As used herein, ammonium phosphate refers to any ammonium salt of any phosphate, including but not limited to any one chemical or combination of chemicals from the following list: ammonium phosphate, NH 4 H 2 PO 4 ; diammonium phosphate, (NH 4 ) 2 HPO 4 ; ammonium polyphosphate, (NH 4 ) salt of
ammonium pyrophosphate, (NH 4 ) 2 H 2 P 2 O 7 ; ammonium metaphosphate, NH 4 PO 3 ; and ammonium orthophosphate. It is understood that such flame and/or fire retardant materials can be used alone in some instances, that is to say as the coating itself, or in combination with other materials suitable for use in the present invention. For example, ammonium phosphate may be used in combination with a polymer, and especially with those polymers disclosed herein.
[0013] It has even been found that ordinary water when applied to the fertilizer particles reduces the level of fuel oil infiltration by decreasing the total number of pores through dissolving and “re-drying” a portion of the fertilizer particle.
[0014] In one preferred embodiment, the coating material comprises a polymer, and more preferably a carboxylate polymer, especially one or more of those set forth in U.S. patent application Ser. No. 09/562,579 and Ser. No. 09/799,210 which are hereby incorporated by reference as though fully set forth herein. Even more preferably the carboxylate polymer comprises a polymer of acrylic acid or it comprises at least two different moieties individually and respectively taken from the group consisting of A, B, and C moieties, recurring B moieties, and C moieties wherein moiety A is of the general formula
[0015] moiety B is of the general formula
[0016] moiety C is of the general formula
wherein R 1 , R 2 and R 7 are individually and respectively selected from the group consisting of H, OH, C 1 -C 30 straight, branched chain and cyclic alkyl or aryl groups, C 1 -C 30 straight, branched chain and cyclic alkyl or aryl C 1 -C 30 based ester groups (formate (C 0 ), acetate (C 1 ), propionate (C 2 ), butyrate (C 3 ), etc. up to C 30 ), R′CO 2 groups, and OR′ groups, wherein R′ is selected from the group consisting of C 1 -C 30 straight, branched chain and cyclic alkyl or aryl groups; R 3 and R 4 are individually and respectively selected from the group consisting of H, C 1 -C 30 straight, branched chain and cyclic alkyl or aryl groups; R 5 , R 6 , R 10 and R 11 are individually and respectively selected from the group consisting of H, the alkali metals, NH 4 and the C 1 -C 4 alkyl ammonium groups, Y is selected from the group consisting of Fe, Mn, Mg, Zn, Cu, Ni, V, Cr, Si, B, Co, Mo, and Ca; R 8 and R 9 are individually and respectively selected from the group consisting of nothing (i.e., the groups are non-existent), CH 2 , C 2 H 4 , and C 3 H 6 , at least one of said R 1 , R 2 , R 3 and R 4 is OH where said polymeric subunits are made up of A and B moieties, at least one of said R 1 , R 2 and R 7 is OH where said polymeric subunits are made up of A and C moieties, and at least one of said R 1 , R 2 , R 3 , R 4 and R 7 is OH where said polymeric subunits are made up of A, B and C moieties.
[0017] In the case of the polymer coatings comprising A and B moieties, R 1 -R 4 are respectively and individually selected from the group consisting of H, OH and C 1 -C 4 straight and branched chain alkyl groups, R 5 and R 6 are individually and respectively selected from the group consisting of the alkali metals.
[0018] One preferred polymer useful with the present invention comprises recurring polymeric subunits formed of A and B moieties, wherein R 5 and R 6 are individually and respectively selected from the group consisting of H, Na. K, and NH 4 and specifically wherein R 1 , R 3 and R 4 are each H, R 2 is OH, and R 5 and R 6 are individually and respectively selected from the group consisting of H, Na, K, and NH 4, depending upon the specific application desired for the polymer. These preferred polymers have the generalized formula
wherein R 5 and R 6 are individually and respectively selected from the group consisting of H, the alkali metals, NH 4 and C 1 -C 4 alkyl ammonium groups (and most preferably, H, Na, K and NH 4 depending upon the application), and n ranges from about 1-10000 and more preferably from about 1-5000.
[0019] As can be appreciated, polymers useful in accordance with the present invention can have different sequences of recurring polymeric subunits as defined above. For example, a polymer comprising B and C subunits may include all three forms of B subunit and all three forms of C subunit. In the case of the polymer made up of B and C moieties, R 5 , R 6 , R 10 , and R 11 are individually and respectively selected from the group consisting of H, the alkali metals, NH 4 , and the C 1 -C 4 alkyl ammonium groups. This particular polymer is sometimes referred to as a butanedioic methylenesuccinic acid copolymer and can include various salts and derivatives thereof.
[0020] Another preferred polymer useful with the present invention is composed of recurring polymeric subunits formed of B and C moieties and have the generalized formula
Preferred forms of this polymer have R 5 , R 6 , R 10 , and R 11 individually and respectively selected from the group consisting of H, the alkali metals, NH 4 , and the C 1 -C 4 alkyl ammonium groups. Other preferred forms of this polymer are capable of having a wide range of repeat unit concentrations in the polymer. For example, polymers having varying ratios of B:C (e.g., 10:90, 60:40, 50:50 and even 0:100) are contemplated and embraced by the present invention. Such polymers would be produced by varying monomer amounts in the reaction mixture from which the final product is eventually produced and the B and C type repeating units may be arranged in the polymer backbone in random order or in an alternating pattern.
[0021] As noted above, it is possible to use polymers of the present invention in combination with other materials, such as fire and/or flame retardant materials. For example, one such combination would comprise a mixture of a polymer comprising B and C type repeating units and ammonium phosphate. When such a polymer comprising B and C type repeating units is used in combination with ammonium phosphate, the ammonium phosphate may comprise a substantial portion of the mixture. However, extremely high levels of ammonium phosphate do not impart appreciably better flame retardant properties in comparison to lower levels. Therefore, for purposes of the present invention, it is preferable that the mixture comprise between about 90-99% by weight polymer and 1-10% by weight ammonium phosphate, more preferably between about 93-97% by weight polymer and 3-7% by weight ammonium phosphate, and most preferably between about 94-96% by weight polymer and 4-6% by weight ammonium phosphate. Most preferably, ammonium phosphate comprises approximately 5% of the total weight of the polymer/ammonium phosphate mixture.
[0022] The polymers useful in accordance with the present invention may have a wide variety of molecular weights, ranging for example from 500-5,000,000, more preferably from about 1,500-20,000, depending chiefly upon the desired end use.
[0023] In many applications, and especially for agricultural uses, polymers used with the invention may be mixed with or complexed with a metal or non-metal ion, and especially ions selected from the group consisting of Fe, Mn, Mg, Zn, Cu, Ni, Co, Mo, V, Cr, Si, B, and Ca. Boron is especially preferred because it may reduce the explosivity or energy released during combustion of ANFO as demonstrated by its use in various fire retardant materials.
[0024] The coating may comprise an additional material dissolved or dispersed in the same solution as the first polymer described above. Such additional materials should be selected based on their ability to increase the hydrocarbon resistance of the coating. Examples of suitable materials include natural and synthetic gums, starches and starch derivatives, polyethers, polysaccharides, polycarboxylates, poly-sulfonates, and a wide range of polymers and copolymers. Polyvinyl alcohol (PVA) is one of the preferred materials in this respect. PVA is a material highly resistant to hydrocarbon diffusion to the point where protective gloves and fuel hoses are products made from PVA. PVA is available in a variety of grades with different hydrolysis levels and molecular weights. Higher molecular weights generally give rise to higher viscosity polymer solutions. Therefore lower molecular weights in the range of about 10,000 to 30,000 are preferred due to their ability to form thin films which coat the particle surface easily. High hydrolysis level PVA is also preferred because of its increased resistance to hydrocarbon diffusion compared to that of PVA with a lower degree of hydrolysis.
[0025] Solid PVA is not rapidly water soluble at room temperature and below, therefore it is preferable that PVA be used in companion with another material of the type previously described. The weight ratio of PVA to the other polymer should be between about 1:100 to 100:1, and more preferably between about 1:10 to 10:1 and most preferably about 1:3.
[0026] It is also within the scope of the present invention to provide a fertilizer coating comprising only PVA. As previously discussed, some agricultural applications will require fertilizer coatings which are more water soluble, in addition PVA is expected to be more expensive than other materials described above, therefore preferred embodiments of the invention contain PVA used in combination with other materials.
[0027] Coatings according to the invention should have a solids content of between about 5-70% by weight and more preferably between about 20-60% with the balance comprising water. The solids content largely depends upon the compatibility of the coating viscosity with the method of application to the fertilizer particles. It is most preferable that the fertilizer coating have a solids content of between about 10-30% by weight.
[0028] The coating is applied as a film to a fertilizer particle to form a coated fertilizer particle. Preferably the fertilizer particle used will be porous and will have a bulk density of about 40 to 60, more preferably about 40 to 50 and most preferably about 44 lbs/ft 3 . However, less porous fertilizer particles with higher bulk densities are also suitable for use in accordance with this invention. Preferred fertilizer particles for use with the current invention are monoammonium phosphate (MAP), diammonium phosphate (DAP), any one of a number of well known N—P—K fertilizer products, and/or fertilizers containing nitrogen materials such as ammonia (anhydrous or aqueous), ammonium nitrate, ammonium sulfate, urea, ammonium phosphates, sodium nitrate, calcium nitrate, potassium nitrate, nitrate of soda, urea formaldehyde, metal (e.g. zinc, iron) ammonium phosphates; phosphorous materials such as calcium phosphates (normal phosphate and super phosphate), ammonium phosphate, ammoniated super phosphate, phosphoric acid, superphosphoric acid, basic slag, rock phosphate, colloidal phosphate, bone phosphate; potassium materials such as potassium chloride, potassium sulfate, potassium nitrate, potassium phosphate, potassium hydroxide, potassium carbonate; calcium materials, such as calcium sulfate, calcium carbonate, calcium nitrate; magnesium materials, such as magnesium carbonate, magnesium oxide, magnesium sulfate, magnesium hydroxide; sulfur materials such as ammonium sulfate, sulfates of other fertilizers discussed herein, ammonium thiosulfate, elemental sulfur (either alone or included with or coated on other fertilizers); micronutrients such as Zn, Mn, Cu, Fe, and other micronutrients discussed herein; oxides, sulfates, chlorides, and chelates of such micronutrients (e.g., zinc oxide, zinc sulfate and zinc chloride); such chelates sequestered onto other carriers such as EDTA; boron materials such as boric acid, sodium borate or calcium borate; and molybdenum materials such as sodium molybdate. Of course, due to its explosive tendencies, ammonium nitrate is the most preferred fertilizer for purposes of the invention.
[0029] The coating is typically applied to the fertilizer particles at a level of from about 0.0001-4% by weight, and more preferably from about 0.01-1.0% by weight, and most preferably 0.25-0.5% by weight based upon the weight of the fertilizer taken as 100%. Additionally, when a coating material comprising carbon is employed, the quantity of carbon comprises about 0.2% by weight or less of the total weight of the coated particle. The film or coating should limit hydrocarbon infiltration of the fertilizer particle pores in comparison to an uncoated fertilizer particle, and preferably should reduce hydrocarbon infiltration by at least 10% in comparison to an uncoated fertilizer particle. Even more preferably, the film should reduce hydrocarbon infiltration by at least 50% and most preferably by at least 80%. Such hydrocarbon materials include fuel oil, diesel fuel, grease, wax, and other materials containing a preponderance of hydrocarbons. By preventing or inhibiting the infiltration of hydrocarbon materials into the fertilizer particle, the fertilizer particles have reduced explosivity tendencies, thereby reducing their usefulness as incendiary devices.
[0030] Another method of reducing the explosivity of agricultural grade fertilizer particles and industrial grade ammonium nitrate embraced by this invention is to selectively supply a quantity of water to the fertilizer particles. In so doing, a portion of the fertilizer particles dissolves thereby reducing the number of pores available for hydrocarbon infiltration. Finally, it is necessary to dry the fertilizer particles in order to avoid imparting to the quantity of particles undesirable characteristics such as clumping and caking.
[0031] Thus far, the description above has focused on the coatings and coated fertilizer particles on an individual particle level. When dealing with large quantities of coated fertilizer particles, especially coated ammonium nitrate particles, it is important to note that complete coating coverage of each individual particle is not always essential. It is possible for the coatings of the invention to reduce or completely eliminate the explosivity of the quantity of particles as a whole so long as a plurality of the particles are at least partially coated. It is even possible to mix quantities of coated and uncoated particles together and still produce a fertilizer mixture that has reduced explosivity characteristics. For even when fuel oil is added to this mixture of particles, the coated particles will absorb little or no fuel and some of the uncoated particles will become super-saturated with fuel oil. Both types of particles reduce the explosivity of the entire quantity of fertilizer particles. It may seem surprising that a super-saturated particle will reduce explosivity of the entire batch, however, if too much oil is added, the ability of the ammonium nitrate to oxidize the fuel oil is reduced. As noted in the El Dorado Chemical article referenced and incorporated above, there is an optimal percentage of fuel oil (about 5.7%) which maximizes the theoretical energy released in the detonation of ANFO. Adding more or less fuel oil tends to decrease the amount of energy released upon detonation. Therefore, such super-saturated fertilizer particles act to reduce the explosivity of the entire quantity of fertilizer particles.
[0032] Advantageously, coatings of the current invention also inhibit the formation of fertilizer dust normally associated with fertilizer handling. Therefore, coatings according to the invention are suitable for use as anti-dusting agents, and may be employed in place of current hydrocarbon based anti-dusting agents.
[0033] Generally, methods of forming coated fertilizer particles in accordance with the invention comprise the steps of providing a fertilizer particle and coating the particle with a film comprising at least one material selected from the group consisting of natural and synthetic gums, starches and starch derivatives, monomers and polymers and copolymers selected from the group consisting of polyethers, polysaccharides, polycarboxylates, polysulfonates, and mixtures thereof. Polymer and copolymer coatings are preferred. The coating may be applied to the fertilizer particle in any manner commonly known or used in the art, such as spraying. The precise coating procedure employed will be based an a number of factors including but not limited to the viscosity of the coating, particle surface morphology, particle size, density, and application equipment available. Regardless of the coating method used, it is preferred that the coating be applied in such a manner as to form an evenly distributed film which will provide an effective barrier against hydrocarbon infiltration of the fertilizer particle.
[0034] Generally preferred embodiments of the fertilizer coating comprise a solution including at least one of a substantially water soluble material, a material substantially insoluble in hydrocarbon materials, a material capable of forming a film including a quantity of polyvinyl alcohol dissolved or dispersed therein, and combinations thereof.
[0035] Preferred embodiments of the coated fertilizer particle of the invention comprise a fertilizer particle coated with a film comprising at least one material. It is more preferable for the material to be substantially water soluble, or substantially insoluble in hydrocarbon materials or still more preferably substantially water soluble and substantially insoluble in hydrocarbon materials.
[0036] Preferred methods of forming the coated fertilizer particle of the invention comprise the steps of providing a fertilizer particle and coating the particle with a film comprising at least one material. Again, it is preferable for the material to be substantially water soluble, or substantially insoluble in hydrocarbon materials or still more preferably substantially water soluble and substantially insoluble in hydrocarbon materials.
[0037] The coating of the invention may also be used in combination with a fertilizer particle. It is generally preferable for the coating to comprise at least one material. It is preferable that the material be substantially water soluble, substantially insoluble in hydrocarbon materials, or capable of forming a film, or a combination thereof.
[0038] Ammonium nitrate is the most preferred fertilizer particle for use with the invention because, when combined with a fuel source such as hydrocarbon materials, it acts as a powerful oxidizer. When brought into contact with an ignition source, the ammonium nitrate has the potential to violently react with the fuel source releasing considerable amounts of energy.
[0039] The most preferred polymer coating of the invention comprises a quantity of PVA dissolved or dispersed in a solution comprising a BC type polymer as described above in a weight ratio of about 1:3 (PVA:BC). The most preferred coating will comprise about 10-30% polymer solids and will be water soluble, insoluble in hydrocarbon materials, capable of forming a film and will have a pH of about 7.0 or less. Most preferably the polymer coating will be applied to an ammonium nitrate fertilizer particle in such as manner so as to form an evenly distributed film providing an effective barrier to hydrocarbon infiltration of the fertilizer particle pores.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0040] The following examples describe preferred compositions and methods in accordance with the invention. It is to be understood that these examples are illustrations only and nothing therein should be deemed as a limitation upon the overall scope of the invention.
EXAMPLE 1
[0041] In this example, agricultural grade ammonium nitrate particles were coated with various polymeric materials, as set forth in Table 1, and then exposed to diesel fuel. The amount of diesel fuel retained by the coated particles compared to the original amount of diesel fuel added was then determined.
[0042] The ammonium nitrate particles were coated with the respective polymers according to one of the following two procedures. The most typical procedure was to weigh out an amount of the polymer solution to be coated onto a petri dish having a diameter of about 90 mm. All polymer solutions used in this experiment contained 50% by weight polymer. An appropriate amount of ammonium nitrate particles were weighed out and rolled onto the petri dish. The dish was then covered and the particles were vigorously swirled across the coating materials for several minutes. An alternative coating procedure was to weigh out an appropriate amount of ammonium nitrate particles and place them into a plastic bag equipped with a closure. The appropriate amount of polymer to be coated onto the ammonium nitrate particles was weighed and added to the bag. The bag contents were agitated vigorously for several minutes.
[0043] The coated granules were then placed into 20 mL glass vials and then saturated with diesel fuel. The diesel fuel is poured on top of the particles and then mixed with them by shaking the vial for approximately 10 minutes. The mixture was then allowed to stand for another 5 minutes to provide the fuel with the opportunity to soak into the particle and achieve intimate contact with the ammonium nitrate particles. The particles were then removed from the vials and placed on a filter with vacuum flow assist. The particles were then thoroughly washed with about 50 mL of tetrahydrofuran (THF). The filter liquid was discarded. The particles were collected from the filter and dried in a vacuum oven for about 10 minutes at about 25 in. Hg at a temperature of about 50° C. before being weighed. The difference between the coated particle weight and the washed and dried particle weight is the amount of fuel the particle retained. The results of these experiments are set forth in Table 1.
TABLE 1 Ammonium Treatment type (% total particle Treatment (g 50% nitrate particle Diesel fuel Washed & dried w/w % original % wt. fuel retained/ Sample # weight attributed to coating) polymer soln.) weight (g) (g) weight (g) fuel retained wt. washed particle 0 None 0.000 9.050 1.021 9.118 7 0.7 1 BC acid (1%) 0.205 10.073 1.014 10.020 ND ND 2 BC NH4 salt, pH 3.5 (1%) 0.208 9.984 1.040 9.971 ND ND 3 BC NH4 salt, pH 7 (1%) 0.208 9.986 1.020 10.020 ND ND 4 BC Na salt, pH 4 (0.5%) 0.100 10.057 1.083 10.079 ND ND 5 None 0.000 11.658 1.165 11.754 8 0.8 6 AB Na salt, pH 7 (1%) 0.220 10.266 1.154 10.646 23 2.5 7 C acid (1%) 0.215 10.289 1.142 10.289 ND ND 8 AB Na salt pH 7 (1%) 0.210 10.146 1.256 10.508 20 2.5 9 BC NH4 salt pH 3.5 (0.5%) 0.108 10.315 1.115 10.318 ND ND 10 B acid (0.5%) 0.102 10.021 1.144 10.037 ND ND 11 BC NH4 salt, pH 3.5 (0.25%) 0.057 10.190 1.168 10.279 5 0.6 12 BC NH4 salt, pH 3.5 (0.125%) 0.057 20.206 2.212 20.359 6 0.6 13 B acid (0.25%) 0.056 10.415 1.221 10.418 ND ND 14 C acid (0.25%) 0.059 10.227 1.178 10.251 ND ND 15 BC acid (0.25%) 0.062 10.652 1.173 10.632 ND ND 16 BC acid (0.125%) 0.060 19.584 2.657 19.608 ND ND 17 Polyacrylic acid (0.25%) 0.067 10.044 1.051 9.905 ND ND
[0044] As used in Table 1 and subsequently:
[0045] AB indicates a 1:1 mole:mole copolymer of maleic acid and vinyl acetate prepared as disclosed in U.S. patent application Ser. No. 09/562,579;
[0046] BC indicates a 1:1 mole:mole copolymer of maleic acid and itaconic acid prepared as disclosed in U.S. patent application Ser. No. 09/562,519;
[0047] B indicates a homopolymer of maleic acid obtained from Rohm and Haas Chemicals (Philadelphia, Pa.);
[0048] C indicates a homopolymer of itaconic acid prepared according to a method similar to that of BC;
[0049] Polyacrylic acid obtained from Aldrich Chemical Company (Milwaukee, Wis.); and
[0050] ND indicates that the measurement was not detectable or below what could be measured.
[0051] Next a series of experiments were performed using the same test procedure above, however the diesel infiltration time was extended to 24 hours. The results are listed in Table 2.
TABLE 2 Treatment type (% total Ammonium w/w % % wt. fuel Sample particle weight attributed to Treatment (g 50% nitrate particle Diesel Washed & dried original fuel retained/wt. # coating) polymer soln.) weight (g) fuel (g) weight (g) retained washed particle 18 None 0.000 10.451 1.130 10.623 15.22 1.62 19 BC acid (0.25%) 0.053 10.134 1.059 10.299 13.08 1.34 20 B acid (0.25%) 0.053 10.137 1.176 10.235 6.08 0.70 21 C acid (0.25%) 0.062 10.061 1.165 10.160 5.84 0.67 22 Acrylic acid (0.25%) 0.067 10.233 1.075 10.364 9.07 0.94 23 AB (0.25%) 0.100 (g 25% soln.) 10.313 1.121 10.385 4.19 0.45 24 BC acid (0.25%) 0.107 (g 25% soln.) 10.131 1.091 10.210 4.79 0.51
[0052] The above data demonstrates that even incomplete and imperfect practice of the invention disclosed herein is highly beneficial. It was further determined that polycarboxylate-containing materials are useful barrier coatings and help decrease diesel fuel infiltration into ammonium nitrate particles under the experimental conditions tested. However, the materials do not give perfect protection when used alone at lengthy exposure times.
EXAMPLE 2
[0053] The purpose of this example was to optimize diesel fuel resistance of two-component coatings. In these experiments, porous paper, S&S paper type #404 (Schleicher & Schuell, Dassel, Germany), was used to simulate porous ammonium nitrate particles. Upon examination using a low-power microscope, the porous paper had generally similar porosity to that of high porosity ammonium nitrate. The porous paper had the added advantage of being of substantially uniform porosity whereas the ammonium nitrate granules were of varying shape and porosity.
[0054] In the first experiment, the optimal percent of polymer solids in a coating was determined. The polymer coatings tested were polymaleic acid, sodium polymaleate at pH 3.5, itaconic acid homopolymer, polyacryilc acid, and BC acid polymer. The coating was applied to an 80×80 mm area on a sheet of porous paper by placing small drops of aqueous coating solution to the paper and spreading them to cover the test area using an inert plastic ruler. The coating was allowed to dry. Next, diesel fuel was dripped onto the coated area and the penetration, or lack thereof, was noted. It was determined that the range of polymer solids in the coating could be about 5-70% by weight, with the range about 10-30% by weight being preferred.
[0055] The next experiments involved adding polyvinyl alcohol, PVA, (Celvol 103 by Celanese Chemicals, Dallas, Tex.), a chemical known for its resistance to hydrocarbon diffusion, to the BC acid polymer coating in order to increase the coating's resistance to diesel fuel penetration. BC acid polymer was used because its performance was superior to the other coatings in the porous paper test described above. Because PVA is much more expensive than BC acid polymer it was desirable to determine the optimal ratio of PVA to BC acid polymer. The optimal ratio of PVA to BC acid polymer was about 1:3 by weight. The optimal mixture was prepared at about 20% w/w total dissolved solids by mixing appropriate amounts of water and BC acid polymer solution at room temperature. In this solution, PVA was dissolved or dispersed and the solution subsequently heated to about 90-95° C. with very vigorous, non-aerating agitation. The mixture was cooled to room temperature, at which time it had a consistency suitable for making coatings. The coating was applied to porous paper in the manner described above. The coating was hard, low-color, smooth to the touch after drying, non-hygroscopic and easily dissolved in water. The percent solids used is dictated by the compatibility with the application technique chosen. In practice, any percent solids solution can be used as long as the coating solution is sufficiently mobile under application conditions to create useful coatings. A useful coating is one that provides an effective barrier to fuel infiltration by being a thin film that coats and covers the particle surface.
[0056] Through these experiments, and for the chosen application method, it was determined that a 1:3 weight ratio of PVA to BC acid polymer was the most effective coating in preventing diesel fuel infiltration.
EXAMPLE 3
[0057] In this example, an alternative method of applying the polymer coating to the fertilizer particles was explored. The method involved placing a piece of flat round filter paper (S&S paper type #404) into a 5.5 inch diameter petri dish so that the paper occupies the entire bottom of the dish. About 2.9 g of the 20% w/w solution prepared in Example 2 is spread onto the paper until the paper is saturated with the liquid, but not to the point where there is liquid on the paper surface. The filter paper should be slightly moist to the touch. About 13 g of ammonium nitrate particles are poured onto the paper surface and rolled around the petri dish for about 1 minute, then removed. The particles are allowed to dry for 15 minutes in the air. This method was found to be highly effective as particles coated using this method do not tend to stick together and are dry and smooth to the touch.
[0058] Any method of particle coating known in the art, such as spraying, may be employed to apply the coating to the ammonium nitrate granules so long as the method results in a sufficient fraction of the surfaces of the fertilizer particles being coated to a sufficient degree. It is preferable to have particles coated with a relatively thin layer of coating so as to reduce the expense involved, preserve fertilizer analysis values, reduce water levels added to the fertilizer and reduce material handling requirements.
EXAMPLE 4
[0059] In this experiment, small particle size, high porosity ammonium nitrate granules coated with a factory applied anti-dusting agent, Galoryl, were tested for diesel fuel infiltration. Typically, porous materials with high surface area per unit weight are very difficult to coat effectively, in addition, such material is optimized for high and very rapid uptake of fuel.
[0060] The granules, obtained from El Dorado Chemical Company (St. Louis, Mo.), were first tested without applying any polymer coating according to the diesel fuel absorption method described in Example 1. The particles retained about 49% of the diesel fuel added to them, and had a fuel content of about 5% w/w after a solvent wash as described in Example 1.
[0061] Another batch of granules were tested after removal of the factory applied anti-dust coating. The anti-dust coating was removed by washing the particles several times in THF and subsequently drying the particles under vacuum overnight at 50° C. The de-coated particles had very similar fuel absorption characteristics to those with the factory applied anti-dusting coating.
[0062] Next, samples of both factory coated and de-coated particles were coated with the 1:3 weight ratio PVA to BC polymer described in Example 2 and tested for diesel fuel infiltration using the method described in Example 1, however the exposure time was increased to 15 minutes rather than 5 minutes after the 10 minute mix time. The diesel infiltration for de-coated particles was below 0.2-0.3% of the particle weight with less than 3% of the original fuel being retained. The factory coated particles did not absorb any detectable diesel fuel.
[0063] This experiment illustrates the high barrier performance of the composition and coating application method under conditions which are generally very favorable for diesel fuel absorption and retention, such as small particle size, high surface area per unit weight, and high porosity. It is understood that for standard agricultural grades of ammonium nitrate, which is normally non-porous and has large particle sizes with low surface areas, this coating method would be even more effective.
EXAMPLE 5
[0064] This example demonstrates that treatment with water alone substantially improves the inhibition of hydrocarbon infiltration into fertilizer particles. The procedure of Example 1 was followed with two exceptions. The first exception was that the particles for this example were soaked in diesel fuel for 10 minutes. The second exception was that the particles were washed with methylene chloride rather than THF. Generally, diesel fuel was added to El Dorado Chemical's low density Ammonium Nitrate coated with Galoryl. Particles with no additional coating were then compared with particles which were sprayed with a 0.5 gal/ton coating of the previously described 50% BC polymer, particles which were sprayed with a 1.0 gal/ton coating of the previously described 25% BC polymer, and with particles that were sprayed (treated) with 0.5 gal/ton of water. The particles were then soaked with diesel fuel for 10 minutes and washed with methylene chloride before being tested for their differences in diesel fuel oil retention. The results of this example are provided below in Table 3.
TABLE 3 Concentration % Difference in Diesel Oil Retention Treating Agent (Gal/ton) Compared With The 50% BC Polymer CK-None — 100 50% BC 0.5 0.00 25% BC 1.0 0.03 Water 0.5 25.00
[0065] As shown by these results, simply spraying the particles with water helps to increase their resistance to hydrocarbon penetration. In this manner, water does not serve as a coating. Instead, the particle surface is melted away, thereby permitting less intrusion of hydrocarbons into pore spaces. | Coatings for agricultural grade fertilizer particles and industrial grade ammonium nitrate are provided which when applied to particles form a protective film which acts as a barrier to inhibit or prevent hydrocarbon infiltration of the fertilizer particle pores and also to physically separate the fertilizer particles and hydrocarbon materials. In so doing, the coating greatly reduces the efficacy of the fertilizer particles as an oxidizing agent for use in incendiary devices, thereby deterring or preventing the use of agricultural grade fertilizers or industrial grade ammonium nitrate in creating weapons of terror. | 2 |
FIELD OF THE INVENTION
The present invention generally relates to data processing systems, and more specifically to interfacing a microcontroller (MCU) to an external synchronous dynamic random access memory (SDRAM).
BACKGROUND OF THE INVENTION
As data processing system bus speeds increase there has been a movement from asynchronous to synchronous memory interfaces. This is especially true for dynamic random access memories (DRAM), due to their relatively slow access speeds. A synchronous interface allows for a significantly faster interface. One speed disadvantage of an asynchronous memory system is that transactions are initiated and completed atomically. Therefore each transaction must be completed before the next transaction is begun. Synchronous memory interfaces allow various stages of the transaction to be pipelined, where requests to the memory and responses from the memory are overlapped.
Although synchronous memories provide speed advantages, they also create unique problems with respect to timing and clocking. This becomes a special burden for a system designer trying to implement a cost effective solution while at the same time meeting design specifications for the devices in a system. Hold times may be very difficult to meet, both from the perspective of the memory and the perspective of a processor. In the microcontroller environment, this can be even more difficult if bus clocks are derived from input signals of different frequencies or large skews with respect to the input clock. Bus specifications may be related to output clocks, and so a simple clock tree arrangement will not guarantee synchronous clocks.
FIG. 1 is a prior art timing diagram of an interface between a micro controller and a synchronous memory. Three signals are illustrated: clock out, SDRAM control out, and SDRAM clock. The clock out signal is generated by the data processing system. The bus specifications are defined with respect to this clock out signal. The SDRAM control out signal is generated by the data processing system and is recognized by a synchronous (SDRAM) memory. The SDRAM clock is the input clock to the synchronous DRAM (SDRAM) memory. Two time intervals are illustrated in FIG. 1. The first period is the output hold time for the data processing system. This is the minimum amount of time between a rising clock edge transition and the transition of an output to the memory. The other time period illustrated is the DRAM input hold time requirement. This is the minimum amount of time that a signal must be held after the DRAM input clock rising edge transition to be successfully recognized. In this illustration, the output hold time is two nanoseconds and the DRAM input hold time requirement is one nanosecond. The result is that the difference, one nanosecond, is the maximum skew allowed between the clock out of the data processing system and the clock into the SDRAM. This minimum skew requirement greatly increases the design complexity required in designing a system using synchronous DRAM (SDRAM). It should be noted that there is a similar requirement for data returning to the micro controller from a synchronous memory.
Prior to this invention, the problem has been solved with relatively expensive external hardware, such as a phased locked loop (PLL), and rigorous circuit board design to tightly control the skew of the clocks.
It would therefore be advantageous to provide a system solution which would allow the setup and hold time requirements of the devices within the system to easily be achieved without rigorous control of the clocks. This would significantly simplify the system design of an interface to a synchronous memory.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying FIGURES where like numerals refer to like and corresponding parts and in which:
FIG. 1 is a prior art timing diagram of an interface between a micro controller and a synchronous memory;
FIG. 2 illustrates, in block diagram form, a data processing system in accordance with the present invention;
FIG. 3 illustrates, in logic diagram form, a portion of output delay in accordance with the present invention;
FIG. 4 illustrates a timing diagram of various signals of output delay of FIG. 3 during the feedback delay mode;
FIG. 5 illustrates a timing diagram of various signals of output delay of FIG. 3 during the positive edge mode of operation; and
FIG. 6 illustrates a timing diagram of various signals of output delay of FIG. 3 during the negative edge mode of operation.
DETAILED DESCRIPTION
Generally, the present invention provides a circuit for interfacing a microcontroller to an external synchronous dynamic random access memory (SDRAM) that solves the timing problem of the prior art by feeding back the output clock signal for controlling the timing of the SDRAM to output delay 36. This feedback clock signal is used to control the output registers of output delay 36 that data, address, and control signal to the SDRAM. By feeding back the clock signal, a gate delay caused by buffering the clock signal improves hold times of the SDRAM relative to the microcontroller. Also, feeding back the clock signal matches the output of data processing system 20 with the input hold times of the SDRAM without requiring complex timing control circuits.
FIG. 2 illustrates, in block diagram form, a data processing system 20 in accordance with the present invention. Data processing system 20 includes a central processing unit (CPU) 22, a bus controller 24, other peripherals 26, SDRAM controller 28, clock generator 32, output delay 36 and multiplexer 30. In the illustrated embodiment, data processing system 20 is a microcontroller (MCU) coupled to a synchronous dynamic random access memory (SDRAM) 38. CPU 22 is coupled to bus controller 24 via a bus labeled "INTERNAL BUS". Also SDRAM controller 28 and other peripherals 26 are coupled to the INTERNAL BUS. Bus controller 24 includes a plurality of bidirectional terminals for both receiving and providing data signals labeled "DATA". Bus controller 24 also includes a plurality of output terminals for providing address signals labeled "ADDRESS". SDRAM controller 28 provides a select signal labeled SYNC -- MODE -- SEL, a RAS control signal labeled "SRAS -- IN" and a plurality of conventional SDRAM control signals labeled "SDRAM -- CNTL". Mux 30 receives addresses from the bus controller 24 and multiplexes them to be compatible with standard DRAM operation. Output delay 36 receives data signals from bus controller 24, address signals from mux 30, and the control signals from SDRAM controller 28. In response, output delay 36 provides data signals labeled "DATA", address signals labeled "ADDRESS", a control signal labeled "SRAS -- OUT", and plurality of plurality of conventional SDRAM control signals also labeled "SDRAM -- CNTL" for accessing and controlling an external SDRAM 38. Note that for convenience, some of the signals entering and leaving output delay 36 have the same name.
Clock generator 32 receives an input clock signal labeled "CLK -- IN", and in response, provides a system clock signal labeled SYS -- CLK to each of the modules of data processing system 20. In addition, clock generator 32 provides an output clock signal labeled "CLOCK -- OUT" to an output terminal of data processing system 20. An application using data processing system 20 may include an external buffer circuit such as buffer 34 to provide a buffered clock signal labeled "EDGE -- SEL" to a clock input terminal of SDRAM 38 and as the feedback signal to output delay 36. In some embodiments, buffer 34 may be included on data processing system 20, or may be omitted.
Other peripherals 26 includes various other module circuits for performing communications, timing and other processing tasks for data processing system 20, such as for example, a serial communications interface module (SCI), a general purpose timer, direct memory access module, or additional memory.
In operation, when SDRAM controller 28 recognizes that an access is requested to SDRAM 38, SDRAM controller 28 receives control of multiplexer 30 and asserts select signal SYNC -- MODE -- SEL as an active high to output delay 36, indicating that the access is to synchronous DRAM 38. When select signal SYNC -- MODE -- SEL is a logic low, output delay 36 may be used to access another type of memory, such as static random access memory (SRAM), or a type of non-volatile memory such as read-only-memory (ROM), or electrically erasable read-only-memory (EEPROM). When the access is to SDRAM 38, SDRAM controller 28 asserts the appropriate control signals to control the access of SDRAM 38. SDRAM 38 is a conventional SDRAM and is accessed in a conventional manner and therefore will not be discussed in detail.
The clock timing for SDRAM 38 is provided by data processing system 20 via buffer 34. The output of buffer 34 is then fed back to output delay 36 to cause the output signals from output delay 36 to match the required timing of SDRAM 38 thereby matching the output timing of output delay 36 with the input timing of SDRAM 38.
Note that in other embodiments, SDRAM 38 may be replaced with other types of synchronous memory such as a synchronous SRAM.
FIG. 3 illustrates, in logic diagram form, a portion of output delay 36 in accordance with the present invention. The circuit illustrated in FIG. 3 is one example of an output of output delay 36 of FIG. 2. All of the other output signals including DATA and ADDRESS include circuits similar to the circuit illustrated in FIG. 3. For example, FIG. 3 illustrates the circuit for outputting the SRAS -- OUT signal. In the case of DATA signals the circuit of FIG. 3 is applicable if SRAS -- IN and SRAS -- OUT are replaced with data signals.
The portion of output delay 36 illustrated in FIG. 3 includes flip-flops 40 and 44, inverter 42, multiplexer 48 and AND logic gate 46. Flip-flop 40 has an input terminal for receiving RAS signal SRAS -- IN. A clock input signal for receiving SYS -- CLK and an output terminal for providing an output signal, labeled "POS -- REG", that changes on a rising edge of clock signal SYS -- CLK. Inverter 42 has an input terminal for receiving SYS -- CLK and an output terminal. Flip-flop 44 has an input terminal coupled to the output terminal of flip flop 40, a clock input terminal coupled to the output terminal of inverter 42, and an output terminal for providing an output signal labeled "NEG -- REG", that changes on a falling edge of clock signal SYS -- CLK. Multiplexer 48 has a first input terminal, labeled "0", coupled to the output terminal of flip-flop 40, a second input terminal, labeled "1", coupled to the output terminal of flip-flop 44, a select terminal, and an output terminal. AND logic gate 46 has an inverted first input terminal for receiving a select signal labeled "EDGE -- SEL", a second input terminal for receiving SYNC -- MODE -- SEL, and an output terminal coupled to the select terminal of multiplexer 48.
In operation, output delay 36 provides three modes of operation: (1) a feedback delay mode, where the output of output delay 36 follows the rising edge of a toggling EDGE -- SEL signal; (2) a positive edge mode, where an output of output delay 36 follows the rising clock edge of clock signal SYS -- CLK; and (3) a negative edge mode, where the output of output delay 36 follows the falling edge of clock signal SYS -- CLK.
When select signal SYNC -- MODE -- SEL is negated, or a logic low, multiplexer 48 couples the output of flip-flop 40 to the output of multiplexer 48. This allows a non-SDRAM access using output delay 36 that uses the rising edge of SYS -- CLK.
Output delay 36 is enabled for an SDRAM access when select signal SYNC -- MODE -- SEL is asserted as a logic high.
The operation of output delay 36 of FIG. 3 will now be discussed in connection with the timing diagrams of FIGS. 4-6. When select signal SYNC -- MODE -- SEL is a logic high, the output of AND logic gate 46 is dependent on the logic state of EDGE -- SEL.
FIG. 4 illustrates a timing diagram of various signals of output delay 36 during the feedback delay mode. In the feedback delay mode, feedback clock signal EDGE -- SEL toggles in response to the CLOCK -- OUT signal of clock generator 32. However, EDGE -- SEL is delayed by an amount equal to the delay of buffer 34. When EDGE -- SEL rises, the output of AND logic gate 46 causes the first input terminal of multiplexer 48 to be provided at the output of multiplexer 48, and when EDGE -- SEL falls multiplexer 48 couples the output of flip-flop 44 to the output of multiplexer 48. Since the input of flip-flop 44 is connected to the output of flip-flop 40 then the output of multiplexer 48 does not change during as EDGE -- SEL transitions from a logic high to a logic low because both flip-flops are providing the same information.
Because the output of output delay 36 is triggered by EDGE -- SEL, the input hold time of the output signals of output delay 36, such as for example SRAS -- OUT, is shifted to match the output signals to the clock input signals of SDRAM 38. This matches the output signals of output delay 36 to the clock signal of SDRAM 38 so that the problems as discussed above in the background are avoided without using a complex clocking scheme.
FIG. 5 illustrates a timing diagram of various signals of output delay 36 of FIG. 3 during the positive edge mode of operation. In this mode of operation, the output of buffer 34 is not fed back to output delay 36, and select signal EDGE -- SEL is held at a logic high causing the output of AND logic gate 46 to provide a logic low at its output terminal. This selects the first input terminal (labeled "0") of multiplexer 48 to provide the output of flip-flop 40 at the output terminal of multiplexer 48. This is used in applications where the feedback delay mode is not required and the SDRAM control signal is required to change on the rising edge of the system clock signal.
FIG. 6 illustrates a timing diagram of various signals of output delay 36 during the negative edge mode of operation. In FIG. 6, select signal EDGE -- SEL is held at a logic low causing the second input terminal (labeled "1") of multiplexer 48 to be coupled to the output of multiplexer 48. This is used in applications where the feedback delay mode is not required and it is desirable that the output of output delay 36 depend on a falling edge of the system clock signal.
Because flip-flops 40 and 44 are utilized, scan testing of data processing system 20 is also supported.
Those skilled in the art will recognize that modifications and variations can be made without departing from the spirit of the invention. Therefore, it is intended that this invention encompass all such variations and modifications as fall within the scope of the appended claims.
Claim elements and steps herein have been numbered and/or lettered solely as an aid in readability and understanding. As such, the numbering and/or lettering in itself is not intended to and should not be taken to indicate the ordering of elements and/or steps in the claims. | A synchronous memory interface feeds back a buffered (34) clock signal to a microcontroller (20) to simplify and improve output hold time for the memory (38). An output delay circuit (36) in the microcontroller (20) is controlled by the same delayed clock signal as the synchronous memory (38). This delay circuit (36) selectively delays memory signals to the synchronous memory (38) from the microcontroller delay circuit (36). The use of flip-flops (40, 44) in the delay circuit (36) provides a mechanism for scan testing. This enables three different selectable modes of operation of the delay circuit (36) providing flexibility in interfacing in different environments. | 6 |
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to an operator control having an operator control lever, in particular for controlling a locomotive or a traction vehicle, and having a sensor device for sensing the operator control position of the operator control lever.
In rail vehicles, for example locomotives or traction vehicles, operator control levers are generally used in which the operator control function which is to be carried out is selected by the operator by adjustment of the deflection angle of the operator control lever. Deflection angles which are assigned a specific operator control function are secured, for example, by a ratchet disk. For analogue determination of position of the operator control lever—for example for monitoring purposes—an angle measuring device is generally used whose measuring range is adapted by the manufacturer to the maximum pivot angle of the operator control lever using, for example, a conversion gear mechanism which is adapted to the operator control lever. This has the advantage that maximum measuring accuracy is achieved during the measurement of angles; but it is disadvantageous that when a component is changed, for example when the operator control lever is replaced, extensive adaptation operations are necessary if the adjustment angle range of the old operator control lever which is to be replaced differs from that of the new operator control lever—for example a new conversion gear mechanism has to be used.
BRIEF SUMMARY OF THE INVENTION
The invention is based on the object of specifying an operator control which is particularly maintenance-friendly and permits replacement of components with little expenditure.
Accordingly, there is provision according to the invention that the sensor device has an angle measuring device which is suitable for measuring the adjustment angle of the operator control lever by forming a digitized angle value, wherein the measuring range of the angle measuring device is larger than the adjustment angle range of the operator control lever, and wherein an evaluation device, which determines the operator control position of the operator control lever on the basis of the digitized angle value of the angle measuring device, is connected to the angle measuring device.
A significant advantage of the operator control according to the invention can be considered to be the fact that said operator control permits different operator control levers with different adjustment angle ranges to be used; this is because owing to the measuring range of the angle measuring device which is provided according to the invention and which is larger than the adjustment angle range of the operator control part, it is possible to use operator control levers with different adjustment angle ranges if a replacement is necessary, for example, for the purpose of maintenance or repair. The measuring results of the angle measuring device can be converted and evaluated electronically because the angle measuring device supplies digitized angle values.
According to one particularly preferred refinement of the operator control, there is provision that the evaluation device has an assignment module which maps each of the digitized angle values supplied by the angle measuring device to an angle of the 360° unit circle—referred to below as unit circle angle. In the evaluation device a lever-specific configuration module is stored in which the associated operator control position of the operator control lever is respectively assigned to each unit circle angle of the operator control lever. The evaluation device is also configured in such a way that it determines the respective unit circle angle with the assignment module, and determines the respective operator control position of the operator control lever with the configuration module and the determined unit circle angle of the operator control lever. A particular characteristic of this variant is that separate modules are used, specifically an assignment module and a configuration module. The function of the assignment module is to convert the digital angle values supplied by the angle measuring device into unit circle angles which are independent of the measuring device. The assignment module therefore describes the mode of operation of the angle measuring device and generates measuring-device-independent measured values on the output side. The function of the assignment module is to map the mode of operation of the operator control lever and to specify what operator control position of the operator control lever is reached for the respective unit circle angles. The assignment module therefore describes the mode of operation of the operator control lever and is independent of the angle measuring device used since the assignment module operates on the basis of the unit circle angles which, as already mentioned, are independent of the angle measuring device used. Using separate modules makes it possible to perform very easy adaptation of the operator control if individual components, such as for example the operator control lever or the angle measuring device, are replaced by another operator control lever or another angle measuring device, since all that is necessary is to adapt the corresponding module, that is to say the assignment module or the configuration module.
The assignment module and the configuration module are preferably formed by software modules, for example in the form of files. Such software modules may also be supplied, for example, by the suppliers of the angle measuring device or of the operator control lever in order to permit easy installation or replacement of the components supplied by them.
Moreover, it is considered advantageous if the angle resolution of the angle measuring device is set in such a way that the digitized angle values can cover the entire angle range of the unit circle of 360 degrees. The angle measuring device can therefore preferably measure adjustment angles in the entire angle range of the unit circle of 360°. With such a refinement of the operator control it is ensured that operator control levers can be used with any complete adjustment angle ranges and that it is always possible to evaluate and determine the respective operator control positions.
The evaluation device may be formed, for example, by a data processing system.
The invention also relates to a rail vehicle, in particular a locomotive or a traction vehicle, having an operator control such as that described above.
The invention also relates to a method for determining the operator control position of an operator control lever of an operator control.
With respect to such a method the invention provides that the adjustment angle of the operator control lever is measured with an angle measuring device by forming a digitized angle value, wherein the measuring range of the angle measuring device is larger than the adjustment angle range of the operator control lever, and wherein the operator control position of the operator control lever is determined with an evaluation device on the basis of the digitized angle value of the angle measuring device.
With respect to the advantages of the method according to the invention, reference is made to the statements above relating to the operator control according to the invention since the advantages of the operator control according to the invention correspond essentially to those of the method according to the invention. Advantageous refinements of the method according to the invention are specified in dependent claims.
The invention will be explained in more detail below with reference to exemplary embodiments; in the drawings:
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 shows by way of example an exemplary embodiment of an operator control according to the invention on the basis of which the method according to the invention is also explained by way of example, and
FIG. 2 shows by way of example the mode of operation of an evaluation device of the operator control according to FIG. 1 if an operator control lever of the operator control is replaced by a new operator control lever with another adjustment angle range.
DESCRIPTION OF THE INVENTION
For the sake of clarity, the same reference symbols are always used for identical or comparable components in the figures.
In FIG. 1 , operator control 10 with an operator control lever 20 which can be pivoted about a lever axis 30 can be seen. The possible adjustment angle range of the operator control lever 20 is characterized in FIG. 1 by the reference symbol Δα. It is apparent that the operator control lever can be pivoted between an angle αmin up to an angle αmax.
A ratchet disk 40 , which is equipped with recesses 50 , 51 and 52 , is connected to the operator control lever 20 . The recesses 50 , 51 and 52 interact with a locking element 60 which is pressure-loaded by a spring 70 and is pressed upward in FIG. 1 . Operator control positions of the operator control lever 20 are predefined by the recesses 50 , 51 and 52 : if in fact the ratchet disk 40 is pivoted in such a way that the locking element 60 can engage in one of the recesses, the respective operator control position of the operator control lever 20 is locked in a sprung fashion by means of the spring 70 .
An angle measuring device 80 , which measures the respective adjustment angle α of the operator control lever 20 and generates angle values D(α) which are digitized on the output side, is connected to the operator control lever 20 and respectively to the ratchet disk 40 .
An evaluation device 90 is connected on the output side to the angle measuring device 80 , the digitized angle values D(α) being fed to the evaluation device 90 . In order to process the digitized angle values D(α), the evaluation device 90 has an angle-measuring-device-specific assignment module ZM which processes the digitized angle values D(α) which are fed to the evaluation device 90 .
Arranged downstream of the angle-measuring-device-specific assignment module ZM is a lever-specific configuration module KM which generates on the output side a signal for the operator control position V(φ) of the operator control lever 20 .
The angle measuring device 80 and the evaluation device 90 form a sensor device 100 of the operator control 10 .
The operator control 10 can be operated, for example, as follows:
The digitized angle values D(α) which are formed by the angle measuring device 80 are fed to the angle-measuring-device-specific assignment module ZM and are processed thereby. In this processing step, the assignment module ZM generates a unit circle angle φ which corresponds to the digital angle value D(α), supplied by the angle measuring device 80 , on the 360° unit circle.
The unit circle angle φ which is generated by the assignment module ZM is transmitted to the configuration module KM in which the associated operator control position V(φ) of the operator control lever is respectively assigned for each unit circle angle φ of the operator control lever 20 . The configuration module KM therefore assigns the stored operator control position V(φ) to the unit circle angle φ which is received by the assignment module ZM, and outputs said stored operator control position V(φ) on the output side at the output of the evaluation device 90 in the form of a corresponding output signal.
FIG. 2 is a schematic illustration of how the assignment module ZM carries out the assignment between the digitized angle values D(α) and the unit circle angle φ. The unit circle K on which unit circle angles φ in the form of dots are indicated can be seen. Angle values which are supplied by the angle measuring device 80 are assigned to the unit circle angles φ. Depending on the operator control lever 20 used, the adjustment angle range Δα according to FIG. 1 can be of different sizes; the starting angles αmin at which pivoting of the operator control lever 20 begins can also differ.
FIG. 2 illustrates by way of example the respective starting angle and adjustment angle range by means of dashed lines for two different operator control levers; in this context, Δβ denotes the adjustment angle range of a first operator control lever, β 0 denotes the starting angle of this first operator control lever, Δ γ denotes the adjustment angle range of a second, different operator control lever and γ 0 denotes the starting angle of this second, different operator control lever.
It is apparent that the adjustment angle ranges and the starting angles are mapped onto unit circle angles of the 360° unit circle. The assignment between the adjustment angles or the digitized angle values D(α) and the unit circle angles φ is independent of the operator control lever used and is determined only by the method of functioning of the angle measuring device 80 . As a result of the assignment of the adjustment angles α to unit circle angles φ, a pre-evaluation is therefore carried out which is determined merely by the mode of operation of the angle measuring device 80 and is independent of the operator control lever. The influence of the operator control lever 20 on the respective operator control position is taken into account by the lever-specific configuration module KM which specifies the respective operator control position as a function of the determined unit circle angle φ. The lever-specific configuration module KM is therefore independent of the angle measuring device 80 used since the mode of operation thereof is described by the assignment module ZM.
The separation of the assignment module ZM and of the configuration module KM then makes it possible to replace the angle measuring device 80 or replace the operator control lever 20 without a large degree of expenditure. If, for example, the operator control lever 20 is replaced by another operator control lever with another adjustment angle range Δα, the evaluation device 90 merely has to load and/or allow for a configuration module KM which describes the method of functioning of the operator control lever 20 . The assignment module ZM can remain unchanged since the angle measuring device 80 as such is not changed.
If on the other hand, the angle measuring device 80 is replaced by another angle measuring device, wherein the operator control lever 20 remains unchanged, all that is necessary is to install in the evaluation device 90 a new assignment module ZM which allows for the mode of operation of the new angle measuring device 80 and permits correct assignment of the digitized angle values D(α) to unit circle angles φ. The configuration module KM can remain unchanged at this point since nothing changes with respect to the operator control lever 20 and therefore with respect to the assignment between the unit angles φ and the respective operator control position.
In summary it is therefore to be noted that using assignment modules which describe the method of functioning of the angle measuring device 80 and configuration modules KM which describe the mode of operation of the operator control lever makes it possible to easily replace and modify individual components of the operator control 10 .
The described use of assignment modules ZM and configuration modules KM therefore makes it possible, in other words, to ensure that each lever position of an operator control lever has an assigned fixed unit circle angle or unit circle angle range independently of a specific operator control function. Therefore, identical unit circle angles are generated in the same position for all the operator control levers independently of specific deflection angles with the result that using a configuration module KM, which is, for example, supplied by the manufacturer of the operator control lever 20 , permits simple parameterization of the operator control 10 with respect to the operator control lever 20 used. If the operator control lever 20 is to be replaced by another operator control lever, all that is necessary after mechanical replacement of the operator control lever is to replace the old configuration module by a new configuration module which characterizes the mode of operation of the operator control lever 20 in terms of its operator control positions which are made available. The other components of the evaluation device 90 , in particular the assignment module ZM which characterizes the method of functioning of the angle measuring device 80 , can remain unchanged.
In summary it is to be noted that the described standardization or modulization of the evaluation device 90 reduces the expenditure on adaptation if parts of the operator control 10 are replaced by other parts, for example by another operator control lever or by another angle measuring device; this is because all that has to be done at the evaluation device is to update the corresponding modules which describe the replaced parts.
LIST OF REFERENCE SYMBOLS
10 Operator control
20 Operator control lever
30 Lever axis
40 Ratchet disk
50 Recess
51 Recess
52 Recess
60 Locking element
70 Spring
80 Angle measuring device
90 Evaluation device
100 Sensor device
α Adjustment angle
Δα Adjustment angle range
Δβ Adjustment angle range
β 0 Starting angle
Δγ Adjustment angle range
γ 0 Starting angle
αmin Angle
αmax Angle
φ Unit circle angle
D(α) Angle value
K Unit circle
V(φ) Operator control position
KM Configuration module
ZM Assignment module | A control apparatus has a control lever, in particular for controlling a locomotive or a traction vehicle, and a sensor device for detecting an operating position of the control lever. The sensor device has an angle measurement device which is suitable for measuring an adjustment angle of the control lever, forming a digitalized angle value. A measurement range of the angle measurement device is greater than an adjustment angle range of the control lever and an evaluation device is connected to the angle measurement device which determines the operating position of the control lever based on the digitalized angle value of the angle measurement apparatus. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to motor vehicles and, in particular, to acoustical insulation for use on interior and exterior surfaces of the passenger compartment of motor vehicles.
BACKGROUND OF THE INVENTION
[0002] Sound attenuating materials are provided for acoustically insulating motor vehicles to reduce the level of noise inside the vehicle passenger compartment. External noises, such as road noise, wind noise, engine noise, vibrations, etc. may be attenuated through the use of various acoustical materials applied to the internal and external surfaces of the passenger compartment. Noises emanating from sources within the passenger compartment may be attenuated through the use of various acoustical materials applied to the internal surfaces of the passenger compartment.
[0003] The attenuation of airborne noise from external sources transmitted through the body structure and components to the passenger compartment is commonly referred to as sound transmission loss. The attenuation of internal airborne noise incident on the interior surfaces of the vehicle is commonly referred to as sound absorption. The specific-airflow resistance, of a material is defined as the air pressure difference across the thickness of the material divided by the linear velocity of the airflow and defines the resistance to air movement through a material. The specific airflow resistance may be expressed in units of mks Rayls (Pa·sec·m −1 ). The airflow resistance of fibrous materials depends among other parameters upon the areal density of the fibrous material, fiber orientation, fiber blend, and fiber diameter. The sound transmission loss and sound absorption of a single layer of material are determined by the weight and airflow resistance.
[0004] There are two types of sound attenuating material used in vehicles. The first type of sound attenuating material or acoustical insulation comprises a molded barrier mat located on the interior surface of the firewall separating the passenger compartment from the engine compartment. This barrier mat system comprises a layer of fiber or foam which rests against the firewall and is attached to a thermoplastic barrier which can be made from ethyl vinyl acetate (EVA), polyvinyl chloride (PVC), or a thermoplastic polyolefin (TPO). These molded barrier mats are designed to have high transmission loss. Increasing the areal mass of the barrier mat and the thickness of the fiber-foam layer increases the transmission loss. Generally, these dual layer sound insulating materials are designed to provide high sound transmission loss at the expense of the sound absorption, which is low because the barrier mat is impermeable.
[0005] The other type of sound attenuating material or acoustical insulation comprises a molded mat located on the interior surface of the firewall separating the passenger compartment from the engine compartment. Resinated cotton and phenolic impregnated polyester fibers are two common types of sound absorption substrates. However, these materials rely on phenolic resin as a strengthening and binder agent. Phenolic resins are undesirable due to the presence of formaldehyde and odors, as well as the need to utilize a high-tonnage press to manufacture a shaped product. Generally, such single layer sound insulating materials are not optimized for sound absorption and transmission loss. To optimize these properties, three or more layers of fibrous material are combined into a laminate in which the individual layers contribute to sound absorption and acoustical transmission loss. However, these are complex structures that require multiple process steps to successfully form into a shaped component.
[0006] It would be desirable to provide an improved sound attenuating material for vehicle passenger compartments in which sound absorption dominates as a sound attenuation mechanism rather than sound transmission loss.
SUMMARY OF THE INVENTION
[0007] In an embodiment of the present invention, an acoustical insulator comprises a first nonwoven layer having a first areal density and a second nonwoven layer coupled with the first nonwoven layer to define a laminate. The laminate is adapted to be applied to a surface of a motor vehicle with the first layer positioned between said second nonwoven layer and the surface when applied to an interior surface of a motor vehicle. The second nonwoven layer has a second areal density less than the first areal density and specific airflow resistance between about 200 mks Rayls and about 1200 mks Rayls.
[0008] The invention therefore provides a sound attenuating material that includes a layer of nonwoven material and an underlying layer supporting the single cap layer. This simple two-layer structure provides acoustical attenuation effective to significantly reduce the audibility of common externally-originated noises, such as road noise and engine noise. In comparison with conventional barrier type acoustical insulators, the layered acoustical insulator of the present invention is realized with substantial cost savings and a lightweight construction. The acoustical insulator is biased toward providing sound absorption rather than sound transmission loss as the mechanism for acoustical attenuation because of the construction of the cap layer, which represents a benefit in comparison with conventional acoustical insulators used to sonically insulate the passenger cabin in motor vehicles.
[0009] These and other benefits and advantages of the invention shall become more apparent from the accompanying drawings and description thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the principles of the invention.
[0011] FIG. 1 is a perspective view of a portion of a passenger compartment partially covered by an acoustical insulator in accordance with the present invention; and
[0012] FIG. 2 is a detailed cross-sectional view of the acoustical insulator of FIG. 1 showing the individual layers of a laminated structure.
DETAILED DESCRIPTION
[0013] With reference to FIG. 1 , a portion of a passenger cabin 10 of a motor vehicle 11 is shown with the instrument panel (not shown) removed to reveal the underlying firewall 12 separating the passenger compartment from the engine compartment. The firewall 12 is almost completely covered by an acoustical insulator 14 . The acoustical insulator 14 may be attached to the firewall 12 with mechanical fasteners or by other attachment methods, such as adhesive, familiar to those skilled in the art. The acoustical insulator 14 functions by absorbing the sound that is transmitted though the firewall 12 and registered holes 16 and cutouts 17 and then reflected from the surface of the instrument panel onto the surface of the acoustical insulator 14 .
[0014] There are various openings or cutouts 17 defined in the sheet metal 12 and registered holes 16 in the insulator 14 for the steering column, brake booster, pedals, cables, hoses, etc., which are commonly referred to by a person of ordinary skill in the art as pass-thru's. Despite variations in the size and number of these registered holes 16 and cutouts 17 among vehicle types, the registered holes 16 and cutouts 17 generally degrade the transmission loss of the acoustical insulator 14 by defining regions through which noise from the engine can pass unimpeded by the acoustical insulator 14 . The area occupied by the holes 16 may be as much as 5% to 20% of the total surface area of the acoustical insulator 14 , contingent upon the vehicle type. Moreover, portions of the acoustical insulator 14 immediately surrounding the holes 17 are typically thinner than other portions of the acoustical insulator 14 more distant from the holes 17 .
[0015] In addition to the interior surface of firewall 12 , the acoustical insulator 14 may find other applications for acoustically insulating the passenger cabin 10 of motor vehicle 11 . For example, the acoustical insulator 14 may be used as a sound insulator for the wheel houses located behind the vehicle rear quarter panels in a sports utility vehicle, minivan, etc.
[0016] With reference to FIG. 2 in which like reference numerals refer to like features in FIG. 1 , the acoustical insulator 14 has a laminated structure that includes a nonwoven support layer 20 and a nonwoven cap layer 22 that provides stiffness and structural integrity. The nonwoven cap layer 22 is supported structurally by the support layer 20 and has a lower areal density (i.e., mass per unit area) than the support layer 20 . The cap layer 22 may be formed from a lofted layer in which the constituent fibers are bound together to supply structural integrity to the porous structure and then calendered to thickness less than 1.5 mm to provide a consolidated nonwoven layer. The support layer 20 and the cap layer 22 have an at least partially contacting face-to-face relationship and are bonded together as understood by persons skilled in the art during the manufacturing process to form a shaped construction suitable for use inside the passenger compartment.
[0017] The support layer 20 is placed into contact with sheet metal 24 of the firewall 12 ( FIG. 1 ) and the cap layer 22 is separated from the sheet metal 24 by the support layer 20 . The support layer 20 provides the structural integrity to the acoustical insulator 14 required for handling, installation, and function and may be manufactured from various natural and synthetic fibers or a porous foam material, such as a polyurethane (PUR). The support layer 20 makes a major contribution to the sound attenuation. The cap layer 22 contributes increases the airflow resistance of the acoustical insulator 14 and significantly improves the sound absorption in a frequency range from 250 Hz to 10 kHz. Typically, the support layer 20 has an areal density ranging from about 80 grams·ft −2 to about 150 grams·ft −2 and the cap layer 22 has an areal density from about 10 grams·ft −2 to about 25 grams·ft −2 .
[0018] In one specific embodiment of the present invention that provides particularly advantageous sound insulation properties, the cap layer 22 is a composite synthetic matrix that includes a mixture of high melt matrix or staple fibers each formed from a homopolymer or copolymer of polyester, which is generally termed polyester herein unless otherwise indicated, and preferably polyethylene terephthalate (PET), and low melt binding fibers each formed from polyester. The cap layer 22 is formed from a layer that is initially about 30 mm to about 10 mm thick and constituted by a mixture of stable and binding fibers. This initial layer is heated to a temperature effective to soften the binding fibers and compressed to less than 1.5 mm, which binds the collection of stable and binding fibers together upon cooling to form cap layer 22 . In alternative embodiments, the binding fibers may be replaced with a thermoplastic powder binder that binds the stable fibers upon heating and compression. The support layer 20 is an underpad consisting of cotton fibers blended with polyester fibers and may include recycled materials. Cap layer mats suitable for use in this embodiment of the present invention are commercially available from, for example, Owens Corning (Toledo, Ohio).
[0019] The cotton and polyester fibers in support layer 20 are preferably cross-lapped to impart structural integrity and strength during the molding process. Cross-lapped fiber mats suitable for use as support layer 20 are commercially available from, for example, Hobbs Fibers (Waco, Tex.).
[0020] To make the acoustical insulator 14 , continuous lengths of layers 20 and 22 are unrolled from individual rolls, paired in a face-to-face arrangement, and cut into blanks. The blanks can be heated using convection, infrared, microwaves, radio frequency, conduction through heated plates, and other conventional methods familiar to persons of ordinary skill in the art. The layers 20 , 22 are preferably heated for about 40 seconds to about 90 seconds at about 300° F. to 360° F. to consolidate the layers 20 , 22 and, thereafter, are transferred to a mold of a form tool. When the mold is closed, the layers 20 , 22 are preferably compressed for approximately 40 seconds to approximately 50 seconds to form the acoustical insulator 14 , which has a three dimensional molded shape that is retained, due to the cooling, after ejection. The mold may be optionally chilled to reduce the cycle time. The formed acoustical insulator 14 is then ejected from the mold, trimmed, and shipped to an assembly line. Alternatively, cold blanks of layers 20 and 22 can be loaded directly into a heated tool without any pre-heating. When the mold of the heated tool is closed, the layers 20 , 22 are heated to about 360° F. to 450° F. and compressed for approximately 25 seconds to 60 seconds to consolidate the layers 20 , 22 to form the acoustical insulator 14 with the three dimensional molded shape that is retained, after cooling.
[0021] In the final product, the acoustical insulator 14 preferably has a total thickness of in the range of about 4 millimeters (mm) to about 37 mm, with the cap layer 22 contributing less than 1.5 mm of the total thickness and the support layer 20 accounting for about 2.5 millimeters to about 35.5 millimeters of the total thickness. In this configuration, the cap layer 22 has a specific airflow resistance between about 200 and about 1200 mks Rayls (Pa·sec·m −1 ), and preferably between about 400 and 700 mks Rayls. In addition, the support layer 20 has a specific airflow resistance less than about 10,000 mks Rayls, and preferably between about 500 and 3500 mks Rayls. The acoustical insulator 14 may be placed on the sheet metal 24 so that the support layer 20 is coextensive with the sheet metal 24 and the cap layer 22 is spaced from the sheet metal 24 by the support layer 20 .
[0022] While the present invention has been illustrated by the description of one or more embodiments thereof, and while the embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of Applicants' general inventive concept. | Acoustical insulation for attenuating sound entering the passenger compartment of motor vehicles. The acoustical insulator comprises dual nonwoven layers in which one nonwoven layer is an airflow control layer and the second nonwoven layer is a support layer positioned between the cap layer and the sheet metal of the firewall separating the passenger and engine compartments. The areal density of the cap layer is less than the areal density of the support layer and, preferably, comprises polyethylene terephthalate (PET) fibers. The cap layer has a specific airflow resistance ranging from about 200 mks Rayls to about 1200 mks Rayls. | 1 |
This application claims the benefit of Belgian Application No. 2002/0227 filed Mar. 29, 2002.
The invention relates to a method for driving one or several pile carriers for the selection of one or several pile yarns.
Such a method is described in GB 2347687, where a mechanical Jacquard machine for a gripper axminster weaving machine is built in a horizontal direction and where there is a positive control of the pile carriers. In this method, the reset position of the pile carriers is situated in an extreme position. The pile carriers moving towards this extreme position are driven by a rod provided with grooves.
A disadvantage of this method is that the reset position of the pile carriers is situated in an extreme position, because of which the working speed of the weaving machine to be reached is restricted.
In EP 785 301 a method is described, where the pile carrier is moving from a position in a first weaving cycle to a position in a second weaving cycle according to a direct path without moving towards an intermediate reference position (reset position).
The disadvantage of such a method is that it is not possible here to verify whether all pile carriers are moving along an exact path. It is no longer possible to recognise if a pile carrier to get stuck or if a pile carrier positioning one or more steps mistakenly.
SUMMARY OF THE INVENTION
The objective of the invention is to provide for a method for driving one or several pile carriers for the selection of one or several pile yarns, the pile carriers moving between a first and a second extreme position for pile selection, and each pile carrier being directly driven through a drive motor, the exact positioning of the pile carrier being verified and the moving of the pile carriers leading to a shorter cycle time and therefore to an increased weaving speed.
This objective may be attained by providing for a method for driving one or several pile carriers for the selection of one or several pile yarns, the pile carriers moving between a first and a second extreme position for pile selection, and each pile carrier being directly driven through a drive motor, and activating the drive motor for driving the pile carrier being effected according to the half reset principle, the pile carrier each time moving over an intermediate position, this intermediate position being a position between two extreme positions for pile selection, and the position of the pile carrier being verified in this intermediate position.
A further objective of the invention is to provide for a method for driving one or several pile carriers for the selection of one or several pile yarns, the pile carriers moving between a first and a second extreme position for pile selection, and each pile carrier being directly driven through a drive motor, and each pile carrier being brought directly from the one to the other position for color selection and being verified from time to time whether the position of all pile carriers is still exact.
This objective may be attained by providing for a method for driving one or several pile carriers for the selection of one or several pile yarns, the pile carriers moving between a first and a second extreme position for pile selection, and each pile carrier being directly driven through a drive motor, and activating of at least one drive motor for driving a pile carrier occurs without half reset, after a number of movements of the pile carrier or after a certain time one half reset movement being carried out to verify whether all pile carriers are still in a verified position, said half reset movement being a movement of one or several pile carriers towards an intermediate position between the two extreme positions for pile selection before moving to a next position for color selection.
In a preferred method according to the invention, said intermediate position is the central position in the middle between the two extreme positions for pile selection.
In a preferred method according to the invention, verification of the central position of a pile carrier occurs by means of a light beam.
This invention will now be further explained by means of the following detailed description of a device, provided for implementing the methods according to the invention and two preferred methods for driving one or several pile carriers for the selection of one or several pile yarns according to the present invention. The intention of this description is exclusively to give a clarifying example and to indicate further advantages and particulars of this invention and therefore may on no account be considered to be a restriction of the field of application of the invention or of the patent rights set forth in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In this detailed description reference is made by means of reference numbers to the attached drawings, in which:
FIG. 1 is a perspective view of a device for driving one or several pile carriers for the selection of one or several pile yarns according to the invention;
FIG. 2 is a detail of the part indicated within a circle in FIG. 1 ;
FIG. 3 is a detail of the part indicated within a circle in FIG. 4 ;
FIG. 4 is a perspective view of two pile carriers each being driven by a drive motor;
FIG. 5 is a top view of a device for driving one or several pile carriers for the selection of one or several pile yarns according to the invention;
FIG. 6 is a side view of a device for driving one or several pile carriers for the selection of one or several pile yarns according to the invention;
FIG. 7 is a perspective view of an alternative embodiment for guiding the pile carriers.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In a device ( 1 ) for driving one or several pile carriers ( 2 ) for the selection of one or several pile yarns ( 15 ) according to the invention, as represented in FIG. 1 , one drive motor ( 4 ), more particularly a rotative drive motor, has been provided per pile carrier ( 2 ), as represented in FIGS. 3 and 4 . These drive motors ( 4 ) are suspended from a structure above the pile carriers ( 2 ). The pile carrier ( 2 ) moving in a plane situated under the motor housing ( 7 ) of the drive motor ( 4 ). On the motor shaft ( 5 ) a gearwheel ( 6 ) has been installed having a radius, which exceeds the distance (A) between the motor shaft and the lower point of the motor housing ( 7 ). This gearwheel directly engages a toothed rack ( 9 ), made of synthetic material, attached to the pile carrier ( 2 ). The width of the gearwheel ( 6 ) and the toothed rack ( 9 ) practically equals the pitch of the pile carriers ( 2 ). Preferably, 16 pitches per length are bridged, 7 or 9 pitches being provided per 2.54 cm (corresponding to 1 inch).
The drive motors ( 4 ) are installed in one line according to the longitudinal direction (X) of the pile carriers ( 2 ), as represented in FIGS. 1 , 5 and 6 . These drive motors ( 4 ) are staggered over a pitch in a direction (Y) at right angles to the longitudinal direction (X) of the pile carriers ( 2 ), as may be seen in FIG. 2 . The gearwheels ( 6 ) being likewise staggered over one pitch.
As may be seen in FIGS. 1 , 2 , 5 and 6 , the gearwheels ( 6 ) are overlapping each other in the longitudinal direction (X) because of which the length of a line of motors in the longitudinal direction (X) is restricted or more motors may be installed over the same length.
To that effect, the motor housing ( 7 ) is provided with a recess ( 10 ) in which a gearwheel ( 6 ) driving an adjacent pile carrier ( 2 ) partly extends.
The pile carriers ( 2 ) are supported by at least three and preferably by four guiding reeds ( 11 ), as shown in FIGS. 1 , 2 , 5 and 6 . In this manner an open reed guiding is obtained where the dust may fall down through the various guiding reeds ( 11 ) and cooling air may flow to the drive motors ( 4 ).
In an alternative embodiment for guiding the pile carriers ( 2 ), as represented in FIG. 7 , guiding of the pile carriers ( 2 ) occurs through a toothed rack ( 9 ) through a guiding piece ( 16 ), attached to the drive motor ( 4 ) itself, for instance, attached to the motor housing ( 7 ) on the gearwheel ( 6 ) side, extending under the pile carrier ( 2 ), so that the connection between the drive motor ( 4 ) and the guiding piece ( 16 ) is a fixed one and is further less dependent on the temperature and less sensitive to vibrations.
This alternative embodiment has the advantage, with respect to the use of at least three guiding reeds ( 11 ), that no greater jamming can occur of the gearwheel ( 6 ) on the toothed rack ( 9 ) because of an expansion of the drive motor ( 4 ) and the gearwheel ( 6 ) due to the temperature. Another advantage is that in case of vibrations the contact between the gearwheel ( 6 ) and the toothed rack ( 9 ) in such an embodiment will be constant, what will not always be the case when using at least three guiding reeds ( 11 ).
Between the bundle of pile yarns ( 15 ) and the first drive motor ( 4 a ) of a line of drive motors ( 4 ), as represented in FIGS. 1 , 5 and 6 , a double-sided guide ( 12 ) is provided which is both supporting and avoiding the upward movement of the pile carriers ( 2 ) caused by the elastic retracting force of the pile yarn ( 15 ). The double-sided guide ( 12 ) is further used to absorb the tooth pressure and the deflection caused by the tooth forces. To that effect, in that place, the pile carriers ( 2 ) are provided with an additional guiding strip ( 13 ) extending above the upper surface of the pile carriers ( 2 ) over a certain length exceeding the stroke length, i.e. the maximum distance between the first and the last pile yarn ( 15 ), which has to be moved. The distance (x) between the double-sided guide ( 12 ) and the first drive motor ( 4 a ) of a line of drive motors ( 4 ), is such that the couple of forces coming into being when a pile yarn ( 15 ) is pulled through the pile holder ( 14 ), as represented in FIG. 1 , is absorbed by an antagonistic couple of forces between drive motor ( 4 a )-gearwheel ( 6 ) and the double-sided guide ( 12 ).
Preferably, the pile carriers ( 12 ) are installed in a practically horizontal position, but they may also be installed in a vertical or inclined position.
Two lines of drive motors ( 4 ) are provided in one module, which has been removably installed.
In order to be able to install the drive motors ( 4 ) in modules, with this alternative embodiment for guiding the pile carriers ( 2 ) as represented in FIG. 7 , the pile carriers ( 2 ) with the toothed racks ( 9 ) need to be shortened to a length where, in the most advanced position of the pile carrier, the gearwheel ( 6 ) is still just engaging the toothed rack ( 9 ). In this manner all pile carriers ( 2 ) connected to the same module may be shifted over 1 time the pitch in the longitudinal direction, so that the gearwheels ( 6 ) will come clear from the toothed racks ( 9 ) and the drive motors ( 4 ), with the guiding pieces ( 16 ) connected to them, may be moved upwards freely.
After the control mechanism of the weaving machine, for instance, the Jacquard machine will have finished to position the pile carriers, so that the pile yarns ( 15 ) required will be presented to the rapiers, the rapiers will take the pile yarns ( 15 ) and pull them out over the pile length required.
Before the blade now will cut through the pile yarns ( 15 ) at the length adjusted by the rapiers, all pile carriers ( 2 ) are moved simultaneously in a direction towards the weaver in order to bring the pile yarns ( 15 ) into a position assuring a better approach of the perpendicularity with respect to the backing fabric when positioning the pile yarns ( 15 ) in the backing fabric.
The advantage of such a method is that the rapier movement, which does not start in the direction of the pile yarn ( 15 ) supplied and pulled out, and therefore will adopt an inclined position when pulled out to pile length, will readopt an upright position, by the additional, controlled movement of the control mechanism, for instance, the Jacquard machine.
Activating at least one drive motor for driving a pile carrier ( 2 ) according to the embodiment of the invention, as described above may happen according to various principles of action, two possible principles of action of which are described, namely with half reset and without half reset.
With the half reset principle of action, starting happens in full reset. With full reset, all pile carriers ( 2 ) are brought into a home position, determined by a mechanical stop, by their respective drive motors ( 4 ). With this mechanical stop position, all drive motors ( 4 ) and toothed racks ( 9 ) are synchronized. From the full reset home position, all pile carriers are activated to a half reset position, being a central position in the middle between two extreme positions for pile selection. From this half reset position, the drive motors ( 4 ) are activated, each to have their pile carrier presented the selected pile yarn ( 15 ) to their respective rapier (not represented in the figure). In an alternative embodiment each drive motor ( 4 ) controls its speed in such a manner that the position for all pile carriers ( 2 ) is attained practically simultaneously. After having reached the position for selection, all pile carriers ( 2 ) will wait during an anticipated time, first to allow the rapiers to grip the selected pile yarns ( 15 ) and secondly to cut off the pile yarns ( 15 ). Thereafter, the drive motors ( 4 ) are activated, in an alternative embodiment, to bring the pile carriers back into the half-reset position. An optical sensor verifies this position, stopping the weaving machine when not all pile carriers ( 2 ) are in position. When the weaving machine is not stopped, this process is repeated from the half reset position.
With the principle of action without half reset, a full reset occurs when starting. With full reset all pile carriers ( 2 ) are brought into a home position, determined by a mechanical stop, by their respective drive motors ( 4 ). All drive motors ( 4 ) and toothed racks ( 9 ) are synchronized with this mechanical stop.
From the full reset home position all pile carriers ( 2 ) are activated to a half reset position, being a central position in the middle between two extreme positions for pile selection. From this half reset position the drive motors ( 4 ) are activated, each to make their pile carrier ( 2 ) present the selected pile yarn ( 15 ) to the rapier. In an alternative embodiment, each drive motor controls its speed in such a manner that the selection position for all pile carriers ( 2 ) is reached practically simultaneously. After having reached the selection position, all pile carriers ( 2 ) will wait during an anticipated time to allow the rapiers to grip the selected pile yarns. Thereafter, the drive motors ( 4 ) are activated to bring all pile carriers straight to their positions in order to present the following selected pile yarn ( 15 ) to the rapier without any possibility to verify that the exact position will be maintained. In an alternative embodiment, activating likewise occurs in a manner that the final position is reached practically simultaneously. This process is repeated from each position of a selected pile yarn ( 15 ). It is however indeed possible to shift over to the half reset principle for one cycle, after an adjustable number of selections, and to carry out the optical verification to verify whether all pile carriers ( 2 ) are still sufficiently synchronized. Thereafter a restart is made according to the principle of action without half reset.
It is further possible to attribute an offset of a number of motor steps to the complete Jacquard, i.e. all the drive motors ( 4 ), in order to compensate a possible set off of the weaving machine, for instance, when the weaving machine has been shifted with respect to the Jacquard part. The central position between the two extreme selection positions or the zero is then transferred over a number of motor steps. | The invention relates to a method for driving one or several pile carriers ( 2 ) for the selection of one or several pile yarns ( 15 ), the pile carriers ( 2 ) moving between a first and a second extreme position for pile selection, each pile carrier ( 2 ) being directly driven through a drive motor ( 4 ), and activating the drive motor ( 4 ) for driving the pile carrier ( 2 ) occurring either according to the half reset principle, the pile carrier ( 2 ), each time being moved over an intermediate position, this intermediate position being a position between two extreme positions for pile selection, and the position of the pile carrier ( 2 ) being verified in this intermediate position, or occurring without half reset, one half reset movement being carried out in verification of the fact whether all pile carriers ( 2 ) are still in the positions verified, after a number of movements of the pile carrier ( 2 ) or after a certain time, said half reset movement being a movement of one or several pile carriers towards an intermediate position between two extreme positions for pile selection before moving to a next position for color selection. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor device capable of transmitting and receiving data and a driving method thereof.
Note that the term “semiconductor device” used in this specification refers to a device in general that can operate by utilizing semiconductor characteristics, and an electro-optical device, a semiconductor circuit, and an electronic device are all included in the semiconductor device.
2. Description of the Related Art
In recent years, a semiconductor device that transmits and receives data without contact using an electromagnetic field or an electric wave has been developed. Such a semiconductor device is called an RF (Radio Frequency) tag, a wireless tag, an electronic tag, a transponder, or the like. Most semiconductor devices currently in practical use have circuits each using a semiconductor substrate (such a circuit is also referred to as an IC (Integrated Circuit) chip) and antennas. In the IC chip, a memory and a control circuit are incorporated.
Although a semiconductor device that can transmit and receive data without contact is popular partly as some railway passes, electronic money cards, and the like, it has been a prime task to provide an inexpensive semiconductor device for further popularization.
SUMMARY OF THE INVENTION
In view of the above current conditions, it is an object of the present invention to provide a semiconductor device including a memory with a simple structure for providing an inexpensive semiconductor device and a manufacturing method thereof.
It is another object of the invention to reduce the number of steps in a manufacturing method of a semiconductor device including a memory.
One feature of the invention is a memory device including a layer containing an organic compound, in which a source electrode or a drain electrode of a TFT provided in the memory device is used as a conductive layer forming a bit line of the memory device. Compared to a structure in which a source electrode or a drain electrode of a TFT is connected to a conductive layer of a memory device through a connection electrode, the present invention, in which a source electrode or a drain electrode of a TFT and a bit line of a memory device are formed with one wire, can reduce contact resistance and wiring resistance. Therefore, the present invention can reduce power consumption of a semiconductor device.
Another feature is that the source electrode or drain electrode of the TFT provided in the memory element portion is processed by etching into the conductive layer which forms the bit line of the memory device.
A constitution of the invention disclosed in this specification is a memory device, as one example thereof is shown in FIG. 1 , includes a bit line extending in a first direction; a word line extending in a second direction perpendicular to the first direction; and a memory cell including a memory element, the memory element includes a laminated structure of a conductive layer forming the bit line, an organic compound layer, and a conductive layer forming the word line, and the conductive layer forming the bit line is an electrode in contact with a semiconductor layer of a thin film transistor.
Another constitution of the invention is a memory device, as one example thereof is shown in FIG. 2 , includes a bit line extending in a first direction; a word line extending in a second direction perpendicular to the first direction; and a memory cell including a memory element, the memory element includes a laminated structure of a conductive layer forming the bit line, an organic compound layer, and a conductive layer forming the word line, the conductive layer forming the bit line is an electrode in contact with a semiconductor layer of a thin film transistor, and the conductive layer forming the bit line includes a first region where two metal films are laminated and a second region where three metal films are laminated.
Another constitution of the invention is a memory device, as one example thereof is shown in FIG. 3 , includes a bit line extending in a first direction; a word line extending in a second direction perpendicular to the first direction; and a memory cell including a memory element, the memory element includes a laminated structure of a conductive layer forming the bit line, an organic compound layer, and a conductive layer forming the word line, the conductive layer forming the bit line is an electrode in contact with a semiconductor layer of a thin film transistor, and the conductive layer forming the bit line includes a first region including a single metal film and a second region where three metal films are laminated.
Another constitution of the invention is a memory device, as one example thereof is shown in FIG. 4 , includes a bit line extending in a first direction; a word line extending in a second direction perpendicular to the first direction; and a memory cell including a memory element, the memory element includes a laminated structure of a conductive layer forming the bit line, an organic compound layer, and a conductive layer forming the word line, the conductive layer forming the bit line is an electrode in contact with a semiconductor layer of a thin film transistor, and the conductive layer forming the bit line includes a first region two metal films are laminated, a second region where three metal films are laminated, and a boundary between the first region and the second region is covered with an insulating film.
Another constitution of the invention is a memory device includes a bit line extending in a first direction; a word line extending in a second direction perpendicular to the first direction; and a memory cell including a memory element, the memory element includes a laminated structure of a conductive layer forming the bit line, an organic compound layer, and a conductive layer forming the word line, the conductive layer forming the bit line is an electrode in contact with a semiconductor layer of a thin film transistor, the conductive layer forming the bit line includes a first region including a single metal film and a second region three metal films are laminated, and a boundary between the first region and the second region is covered with an insulating film.
In each of the above constitutions, the conductive layer forming the bit line is a single-layer film of an element selected from Ti, Al, Ag, Ni, W, Ta, Nb, Cr, Pt, Zn, Sn, In, and Mo, or an alloy or compound material containing the above element as its main component, or a laminated film thereof.
In each of the above constitutions, either or both the conductive layer forming the bit line and the conductive layer forming the word line may include a light transmitting property. In addition, the thin film transistor may be an organic transistor.
In each of the above constitutions, an element including a rectifying property may be provided between the conductive layer forming the bit line and the organic compound layer or between the organic compound layer and the conductive layer forming the word line. Note that, as the element having a rectifying property, a thin film transistor, a diode, or the like whose gate electrode and drain electrode are connected to each other can be used.
In each of the above constitutions, a buffer layer or an organic compound layer is provided in contact with the first region of the conductive layer forming the bit line.
In each of the above constitutions, the memory device is to further include a control circuit for controlling the memory element, and an antenna.
In addition, a method for manufacturing a memory device is also one of the present invention. The method for manufacturing a memory device including a bit line extending in a first direction, a word line extending in a second direction perpendicular to the first direction, and a memory cell including a memory element, the method comprises: forming a bit line including laminated metal layers; forming an insulating film covering at least an end portion of the bit line; thinning a part of the bit line by etching using the insulating film as a mask, thereby forming a depression in the bit line, the depression having a slanted side surface; forming a layer containing an organic compound over the insulating film and the depression; and forming a word line over the layer containing the organic compound.
In addition, another method for manufacturing a memory device is a method for manufacturing a memory device including a bit line extending in a first direction, a word line extending in a second direction perpendicular to the first direction, and a memory cell including a memory element, the method comprises: forming a thin film transistor including a semiconductor layer; forming an insulating film covering the thin film transistor; forming an electrode including laminated metal layers in contact with the semiconductor layer, over the insulating film; removing a part of the electrode, thereby forming a first region and a second region wherein a number of laminated metal layers in the second region is larger than that in the first region; forming an insulating film covering the second region of the electrode and a boundary between the first and second regions; forming a buffer layer over the first region; forming a layer containing an organic compound over the buffer layer; and forming a word line over the layer containing the organic compound.
The present invention can reduce the number of steps in a method for manufacturing a semiconductor device including an active matrix type memory device.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a cross-sectional view showing Embodiment Mode 1.
FIG. 2 is a cross-sectional view showing Embodiment Mode 2.
FIG. 3 is a cross-sectional view showing Embodiment Mode 3.
FIG. 4 is a cross-sectional view showing Embodiment Mode 4.
FIG. 5 is a cross-sectional view showing Embodiment Mode 5.
FIGS. 6A and 6B are top views of an active matrix organic memory device (Embodiment Mode 6).
FIG. 7 is a cross-sectional view of a semiconductor device including an organic memory device and an antenna (Embodiment Mode 7).
FIGS. 8A to 8C are a block diagram of a wireless chip and diagrams showing usage examples of a wireless chip.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiment modes of the present invention are explained with reference to the drawings. However, the invention can be carried out in many different modes. As is easily known to a person skilled in the art, the mode and the detail of the invention can be variously changed without departing from the spirit and the scope of the invention. Thus, the present invention is not interpreted while limiting to the following description of the embodiment modes. Note that the same reference numeral is used to denote the same portion or a portion having a similar function among the drawings shown below, and repetitive description thereof is omitted.
Embodiment Mode 1
FIG. 1 is a cross-sectional view of one example of a semiconductor device of the present invention, specifically, a memory device including a plurality of memory element each of which includes an organic compound layer are arranged (such a device is hereinafter also referred to as an organic memory or an organic memory device).
In FIG. 1 , a TFT (n-channel TFT or p-channel TFT) provided over a substrate 10 having an insulating surface is an element for controlling a current flowing to an organic compound layer 20 b of a memory cell, and reference numerals 13 and 14 denote source or drain regions.
A base insulating film 11 (here, a lower layer thereof is a nitride insulating film and an upper layer thereof is an oxide insulating film) is formed over the substrate 10 , and a gate insulating film 12 is provided between a gate electrode 15 and a semiconductor layer. In addition, a side face of the gate electrode 15 is provided with a sidewall 22 . Further, a reference numeral 16 denotes an interlayer insulating film formed with a single layer of an inorganic material such as silicon oxide, silicon nitride, silicon nitride oxide, aluminum nitride, or aluminum nitride oxide, or a laminated layer thereof. Although not shown here, one memory cell may be provided with one or more TFTs (n-channel TFT or p-channel TFT) in addition to the TFT shown in the diagram. Moreover, although a TFT including one channel formation region is shown here, there is no particular limitation. A TFT including a plurality of channel formation regions may be employed.
As shown in FIG. 1 , a lightly doped drain (LDD) structure, which includes LDD regions 23 and 24 between the channel formation region and the source or drain regions, may be employed. In this structure, a region to which an impurity element is added in low concentration is provided between the channel formation region and the source or drain regions formed by adding an impurity element in high concentration. This region is referred to as an LDD region.
Reference numerals 18 a to 18 c denote layers included in a first electrode layer, in other words, a conductive layer forming a bit line of the memory element. The first electrode layer has a three-layer structure. Here, a titanium film as the conductive layer 18 a , a film containing aluminum as its main component as the layer 18 b , and a titanium film as the layer 18 c are sequentially laminated. It is preferable to use a titanium film as the layer 18 a which is in contact with the source or drain region because contact resistance can be reduced. A film containing aluminum as its main component has low electrical resistance; therefore, it has the advantage of being able to reduce resistance of the entire wiring when having the largest thickness in the three-layer structure. In addition, a film containing aluminum as its main component is easy to be oxidized and to generate a projecting portion such as a hillock when subjected to heat or the like in a subsequent step. Therefore, a titanium film is preferably laminated to prevent oxidation and formation of a projecting portion. A film containing aluminum as its main component becomes an insulating film when oxidized, whereas a titanium film has a semiconductor property even when oxidized. Therefore, a titanium film can suppress an increase in electrical resistance as compared to a film containing aluminum as its main component. Considering these points, the titanium film as the layer 18 a , the film containing aluminum as its main component as the layer 18 b , and the titanium film as the layer 18 c are preferably formed continuously without exposure to the atmosphere.
In addition, a source line including layers 17 a to 17 c is also formed with the same laminated structure (three layers in total). The laminated structure (three layers in total) includes a film containing aluminum as its main component, which can serve as a low-resistance wire, and a connection wire including layers 25 a to 25 c of a connection portion is also formed at the same time.
In addition to the TFTs arranged in the memory element portion, a driver circuit for controlling operation of the memory element portion can also be formed. Further, a lead wiring of the driver circuit can also be formed with the same laminated structure (three layers in total), so that the driver circuit can be formed with a low-resistance wiring. By forming the driver circuit with a low-resistance wiring, power consumption of the driver circuit can be reduced. The driver circuit for controlling operation of the memory element portion is, for example, a decoder, a sense amplifier, a selector, a buffer, a read circuit, a write circuit, or the like.
An insulating film 19 is provided between memory cells. The insulating film 19 is provided at the boundary between adjacent memory cells to surround and cover the periphery of the first electrode layer including the layers 18 a to 18 c . As the insulating film 19 , a single-layer structure of an inorganic material containing oxygen or nitrogen, such as silicon oxide (SiO x ), silicon nitride (SiN x ), silicon oxynitride (SiO x N Y ) (X>Y), or silicon nitride oxide (SiN X O Y ) (X>Y), or the like or a laminated structure thereof can be used. Alternatively, the insulating film 19 is formed to have a single-layer or laminated structure with an organic material such as polyimide, polyamide, polyvinylphenol, benzocyclobutene, acryl, or epoxy, or the like. Further, it may be formed with a laminate of an inorganic material and an organic material.
For a second electrode layer 21 , a single-layer or laminated structure of an element selected from gold (Au), silver (Ag), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), carbon (C), aluminum (Al), manganese (Mn), titanium (Ti), and tantalum (Ta) or an alloy containing a plurality of the elements can be used.
In addition, a laminated layer containing an organic compound (a laminated layer of a first layer (buffer layer 20 a ) and a second layer (organic compound layer 20 b )) is provided between the first electrode layer including the layers 18 a to 18 c and the second electrode layer 21 .
The buffer layer 20 a is a composite layer of an organic compound and an inorganic compound which can exhibits an electron accepting property to the organic compound, specifically, a composite layer containing metal oxide and an organic compound. The buffer layer can also provide excellent conductivity in addition to an effect such as improvement in heat resistance, which is thought to be obtained by mixing an inorganic compound.
Specifically, the buffer layer 20 a is a composite layer containing metal oxide (such as molybdenum oxide, tungsten oxide, or rhenium oxide) and an organic compound (such as a material having a hole transport property (for example, 4,4′-bis[N-(3-methyphenyl)-N-phenylamino]biphenyl (abbr.: TPD), 4,4′-bis [N-(1-naphthyl)-N-phenylamino]biphenyl (abbr.: α-NPD), 4,4′-{N-[4-(N,N-di-m-tolylamino)phenyl]-N-phenylamino}biphenyl (abbr.: DNTPD), or the like)).
By providing the buffer layer on the first electrode layer, a distance between a third layer of the first electrode layer and the second electrode layer in a memory element can be increased, and initial failure due to a short circuit of the memory element caused by surface unevenness of a metal electrode, or the like can be suppressed.
The organic compound layer 20 b as the second layer is formed with a single-layer or laminated layers of a layer formed of an organic compound material having conductivity. As a specific example of the organic compound material having conductivity, a material having a carrier transport property can be used.
In the case where the third layer of the first electrode layer and the second layer 20 b have poor adhesion to each other, the buffer layer can improve adhesion when provided therebetween. Since the buffer layer is the composite layer containing metal oxide and an organic compound, it has good adhesion to both the first electrode layer which is formed of metal and the second layer which is formed of an organic compound.
Although explanation is made here taking a top-gate TFT as an example, the invention can be applied regardless of a TFT structure, for example, to a bottom-gate (inverted staggered) TFT and a staggered TFT. Moreover, the invention is not limited to a TFT having a single-gate structure, and a multi-gate TFT having a plurality of channel formation regions, for example, a double-gate TFT may also be employed.
In this specification, a semiconductor film containing silicon as its main component, a semiconductor film containing an organic material as its main component, or a semiconductor film containing metal oxide as its main component can be used as the semiconductor layer serving as an active layer of the TFT. As the semiconductor film containing silicon as its main component, an amorphous semiconductor film, a semiconductor film having a crystalline structure, a compound semiconductor film having an amorphous structure, or the like can be used. Specifically, amorphous silicon, microcrystalline silicon, polycrystalline silicon, or the like can be used for the semiconductor film containing silicon as its main component. As the semiconductor film containing an organic material as its main component, a semiconductor film containing, as its main component, a substance which includes a certain amount of carbon or an allotrope of carbon (excluding diamond), which is combined with another element, can be used. Specifically, pentacene, tetracene, a thiophen oligomer derivative, a phenylene derivative, a phthalocyanine compound, a polyacetylene derivative, a polythiophene derivative, a cyanine dye, or the like can be used. Further, as the semiconductor film containing metal oxide as its main component, zinc oxide (ZnO); oxide of zinc, gallium, and indium (In—Ga—Zn—O); or the like can be used.
Furthermore, transfer to a flexible substrate may be performed using a peeling technique. In that case, a TFT and a memory device are manufactured after forming a peeling layer or a separation layer over a first substrate such as a glass substrate. Then, the peeling layer or the separation layer is removed, and the TFT and the memory device peeled off from the first substrate may be transferred to a second substrate that is a flexible substrate.
Embodiment Mode 2
In this embodiment mode, an example of a memory device, which has a different structure from that in Embodiment Mode 1, is shown in FIG. 2 .
The structure shown in FIG. 2 includes a first region where part of a first electrode layer is thinner due to etching using an insulating film 219 as a mask, and the first region is in contact with a laminated layer containing an organic compound (a buffer layer 220 a and an organic compound layer 220 b ) of a memory cell. The insulating film 219 is provided at the boundary between adjacent memory cells to surround and cover the periphery of the first electrode layer.
A first electrode layer including layers 218 a to 218 c is a conductive layer forming a bit line of a memory element. The first electrode layer including the layers 218 a to 218 c has a first region with two layers 218 a , 218 b , a second region with three layers 218 a to 218 c , and a step at the boundary between the first region and the second region. Here, a titanium film as the layer 218 a , a film containing aluminum as its main component as the layer 218 b , and a titanium film as the layer 218 c are sequentially laminated.
In addition, a source line including layers 217 a to 217 c is also formed with the same laminated structure (three layers in total). The laminated structure (three layers in total) includes a film containing aluminum as its main component, which can serve as a low-resistance wiring, and a connection wiring including layers 225 a to 225 c of a connection portion is also formed at the same time.
Note that in FIG. 2 , a TFT (n-channel TFT or p-channel TFT) provided over a substrate 210 having an insulating surface is an element for controlling a current flowing to the organic compound layer 220 b of the memory cell, and reference numerals 213 and 214 denote source or drain regions. Further, the TFT shown in FIG. 2 has LDD regions 223 and 224 between a channel formation region and the source or drain regions.
A base insulating film 211 (here, a lower layer thereof is a nitride insulating film and an upper layer thereof is an oxide insulating film) is formed over the substrate 210 , and a gate insulating film 212 is provided between a gate electrode 215 and a semiconductor layer. In addition, a side face of the gate electrode 215 is provided with a sidewall 222 . Further, a reference numeral 216 denotes an interlayer insulating film formed with a single layer of an inorganic material such as silicon oxide, silicon nitride, silicon nitride oxide, aluminum nitride, or aluminum nitride oxide, or a laminated layer thereof.
By providing the buffer layer 220 a on the first electrode layer, a distance between the first electrode layer and a second electrode layer 221 in a memory element can be increased, and initial failure due to a short circuit of the memory element caused by surface unevenness of a metal electrode, or the like can be suppressed. In the case where the second layer 218 b of the first electrode layer and the organic compound layer 220 b have poor adhesion to each other, the buffer layer 220 a can improve adhesion when provided between these layers. In the structure shown in FIG. 2 , the second layer 218 b of the first electrode layer and the buffer layer 220 a are in contact with each other, and part of the first insulating layer 218 c is removed. With the structure in which part of the first electrode layer 218 c is removed and the film containing aluminum as its main component and the buffer layer 220 a are in contact with each other, electrical resistance of a memory element can be reduced.
The organic compound layer 220 b which is the second layer is formed with a single-layer or laminated structure of a layer formed of an organic compound material having conductivity. As a specific example of the organic compound material having conductivity, a material having a carrier transport property can be used.
Note that if there is no particular necessity, the buffer layer 220 a need not necessarily be provided.
In the case of the structure shown in FIG. 2 , the second electrode layer 221 is in contact with the second layer of the first electrode layer in the connection portion. By using materials containing the same metal element for their main components of the second electrode layer 221 and the second layer of the first electrode layer, they can be connected to each other with low contact resistance.
This embodiment mode can be freely combined with Embodiment Mode 1.
Embodiment Mode 3
In this embodiment mode, an example of a memory device, which has a different structure from those in Embodiment Modes 1 and 2, is shown in FIG. 3 .
The structure shown in FIG. 3 includes a first region where part of a first electrode layer is thinner due to etching using an insulating film 319 as a mask, and the first region is in contact with a laminated layer containing an organic compound (a buffer layer 320 a and an organic compound layer 320 b ) of a memory cell. The insulating film 319 is provided at the boundary between adjacent memory cells to surround and cover the periphery of the first electrode layer.
A first electrode layer including layers 318 a to 318 c is a conductive layer forming a bit line of a memory element. The first electrode layer including the layers 318 a to 318 c has a first region with a single layer, a second region with three layers, and a step at the boundary between the first region and the second region. Here, a titanium film as the layer 318 a , a film containing aluminum as its main component as the layer 318 b , and a titanium film as the layer 318 c are sequentially laminated.
In addition, a source line including layers 317 a to 317 c is also formed with the same laminated structure (three layers in total). The laminated structure (three layers in total) includes a film containing aluminum as its main component, which can serve as a low-resistance wire, and a connection wire including layers 325 a to 325 c of a connection portion is also formed at the same time.
Note that in FIG. 3 , a TFT (n-channel TFT or p-channel TFT) provided over a substrate 310 having an insulating surface is an element for controlling a current flowing to an organic compound layer 320 b of a memory cell, and reference numerals 313 and 314 denote source or drain regions. Further, the TFT shown in FIG. 3 has LDD regions 323 and 324 between a channel formation region and the source or drain regions.
A base insulating film 311 (here, a lower layer thereof is a nitride insulating film and an upper layer thereof is an oxide insulating film) is formed over the substrate 310 , and a gate insulating film 312 is provided between a gate electrode 315 and a semiconductor layer. In addition, a side face of the gate electrode 315 is provided with a sidewall 322 . Further, a reference numeral 316 denotes an interlayer insulating film formed with a single layer of an inorganic material such as silicon oxide, silicon nitride, silicon nitride oxide, aluminum nitride, or aluminum nitride oxide, or a laminated layer thereof.
By providing the buffer layer 320 a on the first electrode layer, a distance between the first electrode layer and a second electrode layer 321 in a memory element can be increased, and initial failure due to a short circuit of the memory element caused by surface unevenness of a metal electrode, or the like can be suppressed.
The organic compound layer 320 b as the second layer is formed with a single-layer or laminated structure of a layer formed of an organic compound material having conductivity. As a specific example of the organic compound material having conductivity, a material having a carrier transport property can be used.
Note that if there is no particular necessity, the buffer layer 320 a need not necessarily be provided.
In the case of the structure shown in FIG. 3 , the first layer 318 a of the first electrode layer can have a relatively flat surface since it is thinly formed over the flat interlayer insulating film 316 . Therefore, initial failure due to a short circuit of the memory element caused by surface unevenness of the metal electrode, or the like can be suppressed.
In the connection portion, the second electrode layer 321 and the first layer 325 a of the first electrode layer are in contact with each other, and a side face of a second layer 325 b is also in contact with the second electrode layer 321 . By employing the structure shown in FIG. 3 , a contact area in the connection portion can be increased.
This embodiment mode can be freely combined with Embodiment Mode 1.
Embodiment Mode 4
In this embodiment mode, an example of a memory device, which has a structure partly different from that in Embodiment Mode 2, is shown in FIG. 4 .
An example of performing etching using an insulating film as a mask is described in Embodiment Mode 2, whereas an example of performing etching with one more additional mask to remove part of a third layer of a first electrode layer is described in this embodiment mode.
The structure shown in FIG. 4 has a first region where part of the first electrode layer is thinner due to etching, and the first region is in contact with a laminated layer containing an organic compound (a buffer layer 420 a and an organic compound layer 420 b ) of a memory cell. An insulating film 419 is provided at the boundary between adjacent memory cells to surround and cover the periphery of the first electrode layer.
A first electrode layer including layers 418 a to 418 c is a conductive layer forming a bit line of a memory element. The first electrode layer including the layers 418 a to 418 c has a first region with two layers 418 a , 418 b , a second region with three layers 418 a to 418 c , and a step at the boundary between the first region and the second region. Here, a titanium film as the layer 418 a , a film containing aluminum as its main component as the layer 418 b , and a titanium film as the layer 418 c are sequentially laminated.
In the structure shown in FIG. 4 , the step at the boundary between the first region and the second region is also covered with the insulating film 419 .
In addition, a source line including layers 417 a to 417 c is also formed with the same laminated structure (three layers in total). The laminated structure (three layers in total) includes a film containing aluminum as its main component, which can serve as a low-resistance wiring, and a connection wiring including layers 425 a to 425 c of a connection portion is also formed at the same time.
Note that in FIG. 4 , a TFT (n-channel TFT or p-channel TFT) provided over a substrate 410 having an insulating surface is an element for controlling a current flowing to the organic compound layer 420 b of the memory cell, and reference numerals 413 and 414 denote source or drain regions. Further, the TFT shown in FIG. 4 has LDD regions 423 and 424 between a channel formation region and the source or drain regions.
A base insulating film 411 (here, a lower layer thereof is a nitride insulating film and an upper layer thereof is an oxide insulating film) is formed over the substrate 410 , and a gate insulating film 412 is provided between a gate electrode 415 and a semiconductor layer. In addition, a side face of the gate electrode 415 is provided with a sidewall 422 . Further, a reference numeral 416 denotes an interlayer insulating film formed with a single layer of an inorganic material such as silicon oxide, silicon nitride, silicon nitride oxide, aluminum nitride, or aluminum nitride oxide, or a laminated layer thereof.
By providing the buffer layer 420 a on the first electrode layer, a distance between the first electrode layer and a second electrode layer 421 in a memory element can be increased, and initial failure due to a short circuit of the memory element caused by surface unevenness of a metal electrode, or the like can be suppressed. In the case where the second layer 418 b of the first electrode layer and the organic compound layer 420 b have poor adhesion to each other, the buffer layer 420 a can improve adhesion when provided between these layers.
The organic compound layer 420 b as the second layer is formed with a single-layer or laminated structure of a layer formed of an organic compound material having conductivity. As a specific example of the organic compound material having conductivity, a material having a carrier transport property can be used.
Note that if there is no particular necessity, the buffer layer 420 a need not necessarily be provided.
This embodiment mode can be freely combined with Embodiment Mode 1.
Embodiment Mode 5
In this embodiment mode, an example of a memory device, which has a structure partly different from that in Embodiment Mode 4, is shown in FIG. 5 .
An example of removing part of a third layer of a first electrode layer is described in Embodiment Mode 4, whereas an example where the number of laminated layers in a first electrode layer is four and a fourth layer and a third layer are partly removed is described in this embodiment mode.
The structure shown in FIG. 5 has a first region where part of the first electrode layer is thinner due to etching, and the first region is in contact with a laminated layer containing an organic compound (a buffer layer 520 a and an organic compound layer 520 b ) of a memory cell. An insulating film 519 is provided at the boundary between adjacent memory cells to surround and cover the periphery of the first electrode layer.
A first electrode layer including layers 518 a to 518 d is a conductive layer forming a bit line of a memory element. The first electrode layer including the layers 518 a to 518 d has a first region with two layers 518 a , 518 b , a second region with four layers 518 a to 518 d , and a step at the boundary between the first region and the second region. Here, a titanium nitride film as the layer 518 a , a titanium film as the layer 518 b , a film containing aluminum as its main component as the layer 518 c , and a titanium film as the layer 518 d are sequentially laminated.
In the structure shown in FIG. 5 , the step at the boundary between the first region and the second region is also covered with the insulating film 519 .
In addition, a source line including layers 517 a to 517 d is also formed with the same laminated structure (four layers in total). The laminated structure (four layers in total) includes a film containing aluminum as its main component, which can serve as a low-resistance wiring, and a connection wiring including layers 525 a to 525 d of a connection portion is also formed at the same time.
Note that in FIG. 5 , a TFT (n-channel TFT or p-channel TFT) provided over a substrate 510 having an insulating surface is an element for controlling a current flowing to the organic compound layer 520 b of the memory cell, and reference numerals 513 and 514 denote source or drain regions. Further, the TFT shown in FIG. 5 has LDD regions 523 and 524 between a channel formation region and the source or drain regions.
A base insulating film 511 (here, a lower layer thereof is a nitride insulating film and an upper layer thereof is an oxide insulating film) is formed over the substrate 510 , and a gate insulating film 512 is provided between a gate electrode 515 and a semiconductor layer. In addition, a side face of the gate electrode 515 is provided with a sidewall 522 . Further, a reference numeral 516 denotes an interlayer insulating film formed with a single layer of an inorganic material such as silicon oxide, silicon nitride, silicon nitride oxide, aluminum nitride, or aluminum nitride oxide, or a laminated layer thereof.
By providing the buffer layer 520 a on the first electrode layer, a distance between the first electrode layer and a second electrode layer 521 in a memory element can be increased, and initial failure due to a short circuit of the memory element caused by surface unevenness of a metal electrode, or the like can be suppressed. In the case where the second layer 518 b of the first electrode layer and the organic compound layer 520 b have poor adhesion to each other, the buffer layer 520 a can improve adhesion when provided between these layers.
The organic compound layer 520 b as the second layer is formed with a single-layer or laminated structure of a layer formed of an organic compound material having conductivity. As a specific example of the organic compound material having conductivity, a material having a carrier transport property can be used.
Note that if there is no particular necessity, the buffer layer 520 a need not necessarily be provided.
This embodiment mode can be freely combined with Embodiment Mode 1.
Embodiment Mode 6
In this embodiment mode, one example of a structure of an organic memory is described below. FIG. 6A shows one example of a structure of an organic memory to be described in this embodiment mode, which includes a memory cell array 1222 in which memory cells 1221 are arranged in matrix; a bit line driver circuit 1226 including a column decoder 1226 a , a read circuit 1226 b , and a selector 1226 c ; a word line driver circuit 1224 including a row decoder 1224 a and a level shifter 1224 b ; and an interface 1223 which has a write circuit and the like and interacts with the outside. Note that the structure of a memory device 1216 described here is merely one example. Another circuit such as a sense amplifier, an output circuit, or a buffer may be included therein, and the write circuit may be provided in the bit line driver circuit.
The memory cell 1221 has a first wire 1231 forming a word line Wy (1≦y≦n), a second wire 1232 forming a bit line Bx (1≦x≦m), a transistor 1240 , and a memory element 1241 . The memory element 1241 has a structure in which an organic compound layer is interposed between a pair of conductive layers.
One example of a top surface structure of the memory cell array 1222 is shown in FIG. 6B .
In the memory cell array 1222 , the first wire 1231 which extends in a first direction and the second wire 1232 which extends in a second direction perpendicular to the first direction are provided in matrix. The first wire is connected to a source or drain electrode of the transistor 1240 , and the second wire is connected to a gate electrode of the transistor 1240 . Further, a first electrode layer 1243 is connected to a source or drain electrode of the transistor 1240 , to which the first wire is not connected, and a memory element is formed with a laminated structure of the first electrode layer 1243 , the organic compound layer, and a second conductive layer.
This embodiment mode can be freely combined with any one of Embodiment Modes 1 to 5.
Embodiment Mode 7
In this embodiment mode, a method for manufacturing an organic memory including an antenna is explained with reference to FIG. 7 . Note that FIG. 7 shows an example of using the memory element portion and the connection portion described in Embodiment Mode 1, and the same part as that in FIG. 1 is denoted by the same reference numeral.
Note that FIG. 7 shows an integrated circuit portion such as a bit line driver circuit and an antenna in addition to the memory element portion and the connection portion.
First, a peeling layer (also referred to as a separation layer) is formed over a glass substrate, and a base insulating film 11 is formed. Then, a plurality of transistors serving as switching elements of the memory element portion and an n-channel TFT 27 and a p-channel TFT 26 included in a CMOS circuit of the integrated circuit portion are formed over the base insulating film. Note that in this embodiment mode, one of a source electrode and a drain electrode of each transistor provided in the memory element portion has a function as a first electrode layer including layers 18 a to 18 c . The first electrode layer including the layers 18 a to 18 c can be formed using a vapor deposition method, a sputtering method, a CVD method, a droplet discharge method, a spin coating method, or various printing methods such as screen printing and gravure printing.
In addition, a connection electrode 28 to be connected to an antenna formed in a subsequent step is also formed in the same step as the first conductive layer including the layers 18 a to 18 c.
Subsequently, an insulating film 19 is formed to cover an end portion of the first electrode layer including the layers 18 a to 18 c . In addition, the insulating film 19 is also formed to cover the n-channel TFT 27 and the p-channel TFT 26 of the integrated circuit portion. The insulating film 19 can be formed using a droplet discharge method, a printing method, or a spin coating method. If necessary, the insulating film 19 is formed into a desired shape by patterning.
Next, a buffer layer 20 a and a layer 20 b containing an organic compound are formed over the first electrode layer including the layers 18 a to 18 c . Note that the buffer layer 20 a and the layer 20 b containing an organic compound may be entirely formed, or selectively formed so that the organic compound layers provided in respective memory cells are separated from each other.
Subsequently, a second conductive layer 21 is formed over the layer 20 b containing an organic compound. The second conductive layer 21 can be formed using a vapor deposition method, a sputtering method, a CVD method, a droplet discharge method, a spin coating method, or various printing methods such as screen printing and gravure printing in the same manner as the first conductive layer. A memory element is formed with a laminated structure of at least the first conductive layer including the layers 18 a to 18 c , the layer 20 b containing an organic compound, and the second conductive layer 21 .
In the integrated circuit portion, an electrode 29 is formed in the same step as the second conductive layer 21 . The electrode 29 is electrically connected to the connection electrode provided in an antenna connection portion. In addition, the electrode 29 can improve adhesion between an antenna to be formed later and the insulating film 19 .
Then, an antenna 30 is formed over the electrode 29 . Here, the case where the antenna 30 is provided over the insulating film 19 is described; however, the invention is not limited to this structure. The antenna can be provided below the first conductive layer including the layers 18 a to 18 c or on the same layer.
Note that there are two ways of providing an antenna used for data transmission. One is to provide an antenna over a substrate provided with a plurality of elements and memory elements; the other is to form a terminal portion over a substrate provided with a plurality of elements and memory elements and connect an antenna provided over another substrate to the terminal portion.
Subsequently, the memory element portion including a plurality of memory elements, the connection portion, the integrated circuit portion, and the antenna connection portion, which are provided over the peeling layer, are completely peeled off from the glass substrate. Then, a flexible substrate 32 is attached to the exposed base insulating film 11 with an adhesive layer 31 . A cross-sectional view at the stage after this step is completed corresponds to FIG. 7 .
The flexible substrate 32 corresponds to a laminated film of a film made of polypropylene, polyester, vinyl, polyvinyl fluoride, vinyl chloride, or the like, paper made of a fibrous material, or a base-material film (polyester, polyamide, an inorganic deposited film, paper, or the like) and an adhesive synthetic resin film (an acrylic synthetic resin, an epoxy synthetic resin, or the like), or the like. As the adhesive layer 31 , various types of curing adhesives can be given, for example, a reactive curing adhesive, a thermosetting adhesive, a photo-curing adhesive such as a UV curable adhesive, an anaerobic adhesive, and the like.
An insulating layer serving as a protective layer may be formed by a method such as an SOG method or a droplet discharge method so as to cover the antenna 30 . The insulating layer serving as a protective layer may be formed of a layer containing carbon such as DLC (Diamond-Like Carbon), a layer containing silicon nitride, a layer containing silicon nitride oxide, or an organic material, preferably, an epoxy resin.
A peeling method and a transfer method are not particularly limited. For example, a surface of a side on which the antenna is provided may be attached to a first substratum and the glass substrate is completely peeled off. Subsequently, the exposed surface of the base insulating film 11 may be fixed to the flexible substrate 32 that is a second substratum with the adhesive layer 31 . In this case, either or both heat treatment and pressure treatment may be performed thereafter to seal the memory element portion with the first substratum and the second substratum.
Note that the peeling layer is formed by a method such as a sputtering method or a plasma CVD method with a single layer or laminated layer of a layer formed of an element selected from tungsten (W), molybdenum (Mo), titanium (Ti), tantalum (Ta), niobium (Nd), nickel (Ni), cobalt (Co), zirconium (Zr), zinc (Zn), ruthenium (Ru), rhodium (Rh), lead (Pd), osmium (Os), iridium (Ir), and silicon (Si) or an alloy or compound material containing the element as its main component. A crystal structure of a layer containing silicon may be any of amorphous, microcrystalline, and polycrystalline structures.
In the case where the peeling layer has a single-layer structure, a tungsten layer, a molybdenum layer, or a layer containing a mixture of tungsten and molybdenum is formed, for example. Alternatively, a layer containing oxide or oxynitride of tungsten, a layer containing oxide or oxynitride of molybdenum, or a layer containing oxide or oxynitride of a mixture of tungsten and molybdenum is formed. Note that the mixture of tungsten and molybdenum corresponds, for example, to an alloy of tungsten and molybdenum. In addition, oxide of tungsten is referred to as tungsten oxide in some cases.
In the case where the peeling layer has a laminated structure, a tungsten layer, a molybdenum layer, or a layer containing a mixture of tungsten and molybdenum is formed as a first layer, and a layer containing oxide, nitride, oxyntride, or nitride oxide of tungsten, molybdenum, or a mixture of tungsten and molybdenum is formed as a second layer.
In the case where a tungsten layer is provided as the peeling layer, by applying mechanical force after forming the base insulating film and the element over the peeling layer, the substrate and the base insulating film can be separated from each other within the peeling layer or at the interface therebetween.
In the case where the peeling layer is removed by etching, it is preferable to form an opening to reach the peeling layer by etching the insulating film using a photolithography method.
Note that in the case of forming a laminated structure of a layer containing tungsten and a layer containing oxide of tungsten, the fact that a layer containing oxide of tungsten is formed at the interface between a tungsten layer and a silicon oxide layer by forming the layer containing tungsten and the layer containing silicon oxide thereover, may be utilized. This applies to the case of forming layers containing nitride, oxynitride, and nitride oxide of tungsten. After forming a layer containing tungsten, a silicon nitride layer, a silicon oxynitride layer, and a silicon nitride oxide layer may be formed thereover. Oxide of tungsten is expressed as WO X . X is 2 to 3, and there are cases where X is 2 (WO 2 ), X is 2.5 (W 2 O 5 ), X is 2.75 (W 4 O 11 ), X is 3 (WO 3 ), and the like. In forming oxide of tungsten, there is no particular limitation on the above given value of X, and it may be determined which oxide is formed, based on an etching rate or the like. Note that that which has the best etching rate is a layer containing oxide of tungsten (WO X , 0≦x≦3) formed by a sputtering method in an oxygen atmosphere. Accordingly, it is preferable to form a layer containing oxide of tungsten as the peeling layer by a sputtering method in an oxygen atmosphere for the sake of reduction in manufacturing time.
Alternatively, another peeling method may be used, in which amorphous silicon (or polysilicon) is used for a peeling layer and a gap is generated by releasing hydrogen contained in the amorphous silicon by laser light irradiation to separate the substrate.
In accordance with the above steps, a semiconductor device including a memory element portion and an antenna can be manufactured. In addition, in accordance with the above steps, a flexible semiconductor device can be obtained.
Further, mass production of the semiconductor device including a memory element portion and an antenna becomes possible by using a large-sized substrate (having a size of, for example, 680×880 mm, 730×920 mm, or larger). Note that in the case of forming a large number of semiconductor devices over one substrate, a separately dividing step becomes necessary.
This embodiment mode can be freely combined with any one of Embodiment Modes 1 to 6.
Embodiment Mode 8
In this embodiment mode, the case of using a semiconductor device of the invention as a wireless chip which can transmit and receive data without contact is explained with reference to FIGS. 8A to 8C .
A wireless chip 1310 has a function of communicating data without contact, and includes a power source circuit 1301 , a clock generator circuit 1302 , a data demodulation/modulation circuit 1303 , a control circuit 1304 for controlling another circuit, an interface circuit 1305 , a memory 1306 , a data bus 1307 , and an antenna (an antenna coil) 1308 ( FIG. 8A ).
The power source circuit 1301 is a circuit for generating a variety of power sources which are to be supplied to the respective circuits inside the semiconductor device, based on an AC signal inputted from the antenna 1308 . The clock generator circuit 1302 is a circuit for generating various clock signals to be supplied to the respective circuits inside the semiconductor device, based on an AC signal inputted from the antenna 1308 . The data demodulation/modulation circuit 1303 has a function of demodulating/modulating data which are communicated with a reader/writer 1309 . The control circuit 1304 has a function of controlling the memory 1306 . The antenna 1308 has a function of transmitting and receiving an electromagnetic field or electric wave. The reader/writer 1309 controls processing regarding communication with the semiconductor device, control of the semiconductor device, and data thereof.
The memory 1306 is formed with any of the structures of the organic memories described in Embodiment Modes 1 to 5. Note that a structure of the wireless chip is not limited to the above structure. For example, a structure with another component such as a limiter circuit for power source voltage or hardware dedicated to cryptographic processing may be used.
In addition, the wireless chip may supply a power source voltage to each circuit by an electric wave without a power source (battery) mounted thereon, by a power source (battery) mounted thereon in place of an antenna, or by an electric wave and a power source (battery).
In the case of using the semiconductor device of the invention as a wireless chip or the like, there are advantages in that communication is performed without contact, plural pieces of data can be read, data can be written in the wireless chip, the wireless chip can be processed into various shapes, the wireless chip has a wide directional characteristic and a wide recognition range depending on a frequency to be selected, and the like. The wireless chip can be applied to an IC tag with which individual information on persons and goods can be identified by wireless communication without contact, a label that can be attached to an object by performing labeling treatment, a wristband for an event or an amusement, or the like. Further, the wireless chip may be shaped by using a resin material, or may be directly fixed to metal that hinders wireless communication. Moreover, the wireless chip can be utilized for system operation such as an entrance/exit management system and an account system.
Subsequently, one mode of practical use of a semiconductor device as a wireless chip is explained. A side face of a portable terminal including a display portion 1321 is provided with a reader/writer 1320 , and a side face of an article 1322 is provided with a wireless chip 1323 ( FIG. 8B ).
When the reader/writer 1320 is held over the wireless chip 1323 included in the article 1322 , information on the article 1322 such as a raw material, the place of origin, an inspection result in each production process, the history of distribution, or an explanation of the article is displayed on the display portion 1321 . If the wireless chip is formed over a flexible substrate, the wireless chip can be attached to a curved surface of a product, which is convenient.
Further, when a product 1326 is transported by a conveyor belt, the product 1326 can be inspected using a reader/writer 1324 and a wireless chip 1325 provided over the product 1326 ( FIG. 8C ). Thus, by utilizing a wireless chip for a system, information can be acquired easily, and improvement in functionality and added value of the system can be achieved.
Note that the wireless chip of the invention can be mounted on paper money, coins, securities, certificates, bearer bonds, packing containers, books, recording media, personal belongings, vehicles, food, clothing, health products, commodities, medicine, electronic devices, and the like.
This embodiment mode can be freely combined with any one of Embodiment Modes 1 to 7.
The present invention can reduce the number of steps in mass-producing a semiconductor device including an organic memory. Further, a semiconductor device including an organic memory can be mass-produced using a large-sized substrate of 680×880 mm, 730×920 mm, or larger. | A semiconductor device that can transmit and receive data without contact is popular partly as some railway passes, electronic money cards, and the like; however, it has been a prime task to provide an inexpensive semiconductor device for further popularization. In view of the above current conditions, a semiconductor device of the present invention includes a memory with a simple structure for providing an inexpensive semiconductor device and a manufacturing method thereof. A memory element included in the memory includes a layer containing an organic compound, and a source electrode or a drain electrode of a TFT provided in the memory element portion is used as a conductive layer which forms a bit line of the memory element. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to attenuators and more particularly decade attenuators.
In traditional decade attenuators with multiple taps, compensation for the interaction between steps is difficult to impossible to compensate for. Variable capacitors have been utilized in the prior art attenuators but they perform poorly in extreme environments and they are sensitive to high volume production processes. These capacitors and special high voltage switches for use for high voltage attenuation are quite expensive and bulky.
In accordance with the preferred embodiment of the present invention, an attenuating divider circuit provides signal compensation by a compensation signal which varies with the divider output selected. The basic RC compensation provided for each attenuator path is fine-tuned by this compensation signal which varies with the divider output, i.e. attenuating path, selected. The adjustments in compensation can be accomplished by various techniques which cause the compensation signal to assume the desired electrical characteristics as the various attenuator paths are selected. In the preferred embodiment, variable resistors are provided as alternate paths for the compensating signal in response to the selection of the corresponding signal attenuation path in the divider.
The compensating signal is provided to a common electrical point of the divider via an additional signal compensation circuit element. The particular resistance value selected in combination with this additional signal compensation element, e.g. a capacitor, acts in shunt with compensation elements in the divider circuit to achieve a desired combined RC value for that attenuation path and thus provide the high frequency signal compensation of the output signal.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a circuit diagram of a first attenuator divider circuit with signal compensation in accordance with the preferred embodiment.
FIG. 2 is a circuit diagram of a second attenuator divider circuit with high frequency compensation in accordance with the preferred embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An input signal is received on a line 102. The signal on line 102 is selectively switched to line 129 via one of switches 109, 113, 117, or 125. If switch 109 is activated then no attenuation of the input signal occurs between line 102 and line 129. Successively greater attenuation of the signal on line 102 occurs if switch 113, 117, or 125 (in that order) is selected. This is because of the divider formed by resistors 106, 110, 114, and 120. In this circuit, the greatest attenuation occurs if switch 125 is selected and the attenuation is, of course, determined by the specific resistor values selected for resistors 106, 110, 114 and 120.
Capacitor 124 and capacitors 108, 112 and 116 (if they are electrically included in the circuit because of the activation of switches 125, 117 or 113) provide high frequency signal compensation by formation of the appropriate RC network with resistors 106, 110, 114 and 120.
While adjustment of component values for optimum frequency compensation for one attenuation path would seem readily achievable, it should be noted that variation of the component values to effect the desired compensation at one attenuation path of the divider will effect the compensation at other nodes because of the interdependence and interreaction of the node circuit elements. Therefore, the fine tuning of the frequency compensation for each attenuation level is best achieved in a manner which is independently adjustable for each attenuation path. Furthermore, a desirable attribute of such a compensation scheme would be operation at low voltages which were capable of semiconductor operation so that the use of electromechanical relays is not required as with previous techniques.
The fine tuning compensation technique of the preferred embodiment will now be explained. For initial discussion purposes it will be assumed that switch 150 is closed and resistor 160 is set to zero ohms of resistance between lines 142 and 152. The voltage divider output signal on line 129 drives unity gain amplifier 130 which provides the signal output on line 135. This output signal on line 135 in turn drives non-inverting amplifier 140 which has a gain of K. Amplifier 140 drives signal junction 119 through capacitor 118.
The effect of amplifier 140, since R160 (in this instance) is set to pass all of the signal, is dependent on its gain, K. If K is zero, then the output of amplifier 140 on line 142 will also be zero and hence capacitor 118 will act in parallel with capacitor 124. If K of amplifier 140 is set to one, the output signal on lines 142 and 152 will match the value of the input signal at the input of amplifier 140. There will be a zero voltage drop across capacitor 118 and therefore it will have no effect on the circuit operation. Similarly, if the gain of amplifier 140 is set to 2, the effect of capacitor 124 will be diminished by an amount equal to capacitor 118. In general:
Capacitance 124 effective=Capacitance 118+Capacitance 124 (1-K)
As illustrated above, network compensation can be accomplished by varying the effective capacitance of capacitors 118 and 124. One technique in accordance with the preferred embodiment would be to vary the gain, K, of amplifier 140. Alternatively, the effective gain of amplifier 140 can be preadjusted by the use of potentiometers 160, 162, and 164 which are switched into the circuit by closing the appropriate form A switch 150, 154, or 158, respectively. The selected switch 113, 117, or 125 is closed concurrently with the closing of switch 150, 154, or 158, respectively.
For example, when selecting the attenuation path by closing switch 117, switch 154 is also closed to allow adjustment of the compensation via variable resistor 162. In this case, the gain of amplifier 140 remains fixed at a level which is sufficient to allow suitable adjustment over the resistance ranges of variable resistors 160, 162, and 164. The adjustment of the variable resistor 160, 162, or 164 in the circuit has precisely the same effect as varying the gain of amplifier 140. The resistance values of resistors 160, 162, and 164 are chosen to be small enough so that the loading effects of capactior 118 take place at frequencies well above the intended frequency range of intended operation.
As different nodes are selected, via switches 125, 117, 113, and 109 the compensation signal provided through capacitor 118 continues to propagate upward through the divider, having no effect however if the zero attenuation path is selected via switch 109.
To more clearly envision this, imagine that the divider circuit attenuates in decade steps and the input is grounded, i.e. no input signal is present. A compensation signal on line 152 will enter the bottom divider node 119 via capacitor 118. Assume further that such signal has a level of one volt. One can assume that the RC time constants of each section are substantially equal to begin with since RC time constant matching of each section is a primary objective of the attenuator design.
With these assumptions in mind, the compensating signal level at the node between capacitors 112 and 116 will be 0.99 Volts while it will be 0.9 V at the node between capacitors 108 and 112. Thus 90% of the compensating signal is still effective at the most remote node for which compensation is being provided.
In general, the compensation at any divider tap can be approximately calculated by knowing the gain of amplifier 140, the capacitance of capacitors 118 and 124, and the network attenuation ratio from the bottom tap to the selected tap of the divider. The formula is:
Range=K×C.sub.118 /(C.sub.124 +C.sub.118)
Parasitic capacitances will effect the actual response of the network.
It should be noted that the entire circuit works at semiconductor device level voltages so that the switches indicated in the circuit diagrams can be fabricated using semiconductor techniques, i.e. the actual switches used could be CMOS devices rather than mechanical switches or relays.
An alternative to the above use of form A switches is shown in FIG. 2. In this circuit, the output of amplifier 140 is attenuated by a multiplying digital to analog converter 360 which provides the compensating signal on line 152. The digital control word received on line 362 which can be provided by a microprocessor or digital controller is used to program DAC 360 for some gain between zero and one. The signal from amplifier 140 is thus effectively multiplied by a proportional amount specified by the digital control word on bus 362. In a practical system, the same control computer would also specify the switch (109, 113, 117, or 125) which is to be closed, so for each range change, a corresponding compensation digital control word would be transmitted to DAC 360.
The following guidelines are useful in choosing element values in the application of these compensation methods. Adjustment range is given by the formula set forth above. It should be set by first making K (the fixed gain of amplifier 140) as large as practical and then choosing just enough capacitance for capacitor 118 to give acceptable adjustment range.
Section time constants should be chosen such that compensation capacitance dominates the divider performance at frequencies well below those where stray capacitance would affect the performance of the resistive divider by itself. Capacitor 124 is diminished in capacitance value from that predicted by an amount equal to the capacitance chosen for capacitor 118. This maintains the proper total time constant with both capacitors acting upon the bottom node. Stray capacitance including load and relay bridging capacitance if relays are used, can be nominally accounted for with slight adjustment of compensating element values. Since changing one element value affects the midband response flatness at all nodes, it is best to first analyze a proposed configuration using computer modeling or some other network analysis technique to predict node response sensitivities to element variations. Quick optimization may then be achieved. | A high voltage attenuator is discussed which includes a divider having a signal input line and a plurality of signal output lines for providing an attenuated electrical signal on a selected one of the signal output lines in response to a switching control signal. A compensation means is also coupled to said divider means to provide signal compensation to the attenuated electrical signal in response to the switching control signal, together with switching control means coupled to the divider means to provide the switching control signal. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2006-297044, filed Oct. 31, 2006, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a valve unit of an internal combustion engine in which a valve characteristic of an intake valve or an exhaust valve is continuously controlled.
2. Description of the Related Art
In a valve unit of a multicylinder reciprocating engine (internal combustion engine) mounted on an automobile, in order to reduce fuel consumption by exhaust gas measures or by improving pumping loss, a variable valve in which a characteristic of an intake valve (or an exhaust valve) is continuously and variably controlled is incorporated in a head part of a cylinder head covered with a rocker cover.
In most variable valve units, a structure is used in which a characteristic of an intake valve, e.g., an opening/closing timing or a valve lift amount is continuously varied by a rotational displacement of a control shaft received from a cam. A variable valve unit of this type is disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2005-299536.
In most methods of installing such a variable valve unit, a method is used in which, a cylinder head is mounted on a cylinder block on a main line for assembling engines, and each part of the variable valve unit is attached to each corresponding section of the cylinder head, thereby assembling the entire variable valve unit.
In recent times, in order to increase production efficiency of the main line, on the main line, work in which only camshafts and valves are attached to a cylinder head is performed. On a sub-line separate from the main line, a method is used in which a variable valve unit constituting a part of a cylinder head from a camshaft to a valve is modularized.
That is, only the variable valve unit, which is troublesome in assembly, is modularized on the sub-line, the modularized variable valve unit is returned to the main line, and the variable valve unit is attached to a cylinder head (which is already equipped with camshafts and valves). By doing so, a measure is used in which a working process taking much time is reduced on the main line. Assembling methods of such a type are disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2005-299536 and Jpn. Pat. Appln. KOKAI Publication No. 2005-299538.
Incidentally, the variable valve unit is required to continuously control valves of cylinders in accordance with the same valve characteristic so that a set performance can be exhibited in any operational state of an engine. For that purpose, the variable valve unit is required to undergo adjustment work for adjusting a valve drive output in accordance with a cam profile of each cam for each cylinder, thereby eliminating variation between cylinders.
However, in the above adjustment for eliminating variation between cylinders, troublesome and considerably time-consuming fine adjustment work for making relationships between cams and parts of the variable valve unit for receiving the cams with respect to the respective cylinders so that the continuously variable valve characteristic can be appropriately exhibited is required.
Particularly, in the technique disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2005-299536, a contrivance is employed in which an adjustment mechanism is incorporated in the variable valve unit, the adjustment mechanism having a structure in which a position of a part for receiving a cam is made adjustable, thereby facilitating the adjustment work. For this reason, the adjustment work can be performed only after the variable valve unit provided with parts for receiving cams of a camshaft is attached to the cylinder head provided with camshafts. Therefore, on the main line for assembling engines, considerably time-consuming adjustment work (adjustment for eliminating variation between cylinders) is still required, which is a factor for causing stagnation of the main line.
Furthermore, in the adjustment for eliminating variation between cylinders, not only simply making positional relationships between cams and parts for receiving the cams uniform, but also making uniform the valve characteristics on the basis of the continuously variable control shaft is needed. Accordingly, work for attaching a sensor for detecting a rotational displacement of the control shaft, and work for adjusting the sensor is required on the main line. Such work is also a factor causing stagnation of the main line. Particularly, the sensor is an important part for continuously and variably controlling the valve characteristic. Therefore, the attaching of the sensor must be performed in consideration of maintenance because maintenance of the sensor is required in a state where the assembly of the engine is finished or after the engine is completed as a product. Considering these requirements, considerably difficult problems must be solved to eliminate the stagnation of the main line.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide a valve unit of an internal combustion engine that can improve the productivity of the internal combustion engine.
The valve unit of the present invention comprises: a camshaft provided with a cam for each cylinder; a variable valve operating mechanism for receiving a displacement of the cam, outputting a valve drive output, and continuously variable-controlling the valve drive output in accordance with a rotational displacement of a control shaft provided substantially in parallel with the camshaft; a sensor for detecting the rotational displacement of the control shaft; and a retaining member for retaining the camshaft, the variable valve operating mechanism, and the sensor, wherein the sensor is exposed to the outside of the rocker cover, thereby fixing the camshaft, the variable valve operating mechanism, and the sensor to the cylinder head through the retaining member.
That is, in the valve unit, the camshaft and the sensor are also combined with the valve unit, and hence the valve unit becomes a structure in which cylinder-to-cylinder variation can be adjusted singly. In other words, unlike the conventional case, it is possible not only to complete the assembly of the valve unit on a line separate from the line for assembling internal combustion engines but also to perform adjustment of cylinder-to-cylinder variation, e.g., adjustment of cylinder-to-cylinder variation using a simulation system in which a cylinder head of an internal combustion engine is simulated. Accordingly, the work required on the main line is only work for attaching a valve unit, for which adjustment has already been finished, to a cylinder head on the main line. The cylinder-to-cylinder variation adjustment work and the troublesome work for attaching the sensor and adjusting the sensor, which become factors causing stagnation on the main line, are made unnecessary. Furthermore, the sensor is attached to the cylinder head in a state where it is arranged outside the rocker cover, and hence maintenance thereof can be facilitated.
In a desirable aspect of the present invention, a configuration including an adjustment mechanism capable of adjusting the valve drive output for each cylinder is employed in the variable valve operating mechanism.
In another desirable aspect of the present invention, the configuration is made such that a sensor for detecting the rotational displacement is arranged at an axial end of the control shaft, and the other end of the control shaft is coupled to an actuator mechanism for rotationally displacing the control shaft.
In another desirable aspect of the present invention, the retaining member comprises a holder member for holding one side of the camshaft in the diametric direction, the variable valve operating mechanism, and the sensor, a cap member for holding remaining one side of the camshaft, and a fixing bolt member which penetrate the holder member and the cap member, and can be screwed into the cylinder head.
In a further desirable aspect of the present invention, the Plurality of retaining members are provided so as to axis-support at least both ends of the camshaft and the control shaft, and the retaining members are connected to each other by the camshaft and the control shaft.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.
FIG. 1 is a partial cutaway perspective view showing a cylinder head of an internal combustion engine according to an embodiment of the present invention together with a valve unit mounted on the cylinder head.
FIG. 2 is an exploded perspective view showing the modularized variable valve unit together with peripheral units and devices.
FIG. 3 is an exploded perspective view for explaining structures of parts of the variable valve unit.
FIG. 4 is a cross-sectional view around a sensor taken along a line indicated by an arrow A in FIG. 1 .
FIG. 5 is a cross-sectional view around the cylinder head taken along line B indicated by an arrow B in FIG. 1 .
FIG. 6 is a cross-sectional view around the cylinder head taken along line C indicated by an arrow B in FIG. 1 .
FIG. 7 is a cross-sectional view taken along line D-D in FIG. 2 .
FIG. 8 is a cross-sectional view showing an engine equipped with a valve unit of an internal combustion engine according to a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A variable valve unit of an internal combustion engine according to a first embodiment of the present invention will be described below with reference to FIGS. 1 to 7 . FIG. 1 shows a perspective view of a head part of an engine main body in a reciprocating inline four-cylinder petrol engine, which is an example of a multicylinder internal combustion engine. FIG. 2 is a perspective view showing a state where the head part is disassembled. FIGS. 4 to 7 are cross-sectional views respectively showing states where respective parts (cross sections taken along lines A, B, and-C in FIG. 1 , and line D-D in FIG. 2 ) are cross-sectioned.
A reference numeral 1 in FIG. 1 denotes a cylinder head mounted on a head part of a cylinder block 2 (shown in only FIG. 5 by two-dot chain lines). A reference numeral 3 denotes a rocker cover covering an upper part of the cylinder head 1 . A reference numeral 4 denotes SOHC type variable valve unit which is in a space between the cylinder head 2 and the rocker cover 3 . The variable valve unit 4 is an example of a valve unit of the present invention.
The cylinder head 1 is provided with a head main body 1 x. As shown in FIGS. 1 , 2 , and 5 , the head main body 1 x is surrounded by a peripheral wall 1 a at an upper part thereof. A top surface 1 y of the head main body 1 x is made lower than a rocker cover attaching seat 1 b formed at an upper end part of the peripheral wall 1 a as shown in FIGS. 5 and 6 .
Combustion chambers 7 (shown in only FIG. 5 ) are formed on an undersurface of the head main body 1 x so as to correspond to four cylinders 6 (shown by two-dot chain lines in only FIG. 5 ) formed in the cylinder block 2 . A pair of intake ports 8 and a pair of exhaust ports 9 (both of which are shown in a part of FIG. 5 ) which extend from the combustion chamber 7 are formed on both sides (in the width direction) of the head main body 1 x.
To the intake ports 8 of these ports, a pair of normally-closed intake valves 8 a are attached. A pair of normally-closed exhaust valves 9 a are attached to the exhaust ports 9 . Stem ends of the valves 8 a and 9 a protrude upwardly from the top surface 1 y of the head main body 1 x. Incidentally, for example, an ignition plug is attached to each combustion chamber 7 , and an injector is attached to each cylinder (both are not shown).
In the variable valve unit 4 , a modularized structure in which various parts are assembled is employed. To specifically describe the modularization, as shown in, for example, FIGS. 2 and 5 , a variable valve operating mechanism 13 of the intake side having an adjusting function, a control shaft 14 (serving also as a rocker shaft for intake) for controlling the variable valve operating mechanism 13 , a camshaft 15 , a shaft displacement detection sensor 16 (corresponding to the sensor of the present application) for detecting a rotational displacement of the control shaft 14 , and a rocker arm mechanism 17 (only a part thereof is shown in FIG. 5 ) of the exhaust side are assembled by using a plurality of (five) retaining members 11 a to 11 c (only three representative ones are shown).
Structures of respective parts will be described below. The retaining members 11 a to 11 c are, as shown in FIGS. 1 and 2 , parts each having a wall-shape divided in accordance with an arrangement of each of the cylinders 6 (four), and arranged at the foremost part of the cylinder array, between the cylinders, and at the backmost part in parallel with each other. Incidentally, the retaining members may be only the foremost and backmost members in the case of modularization. However, it is desirable that the retaining member be provided between the cylinders in consideration of the rigidity and the like.
As shown in FIG. 3 , a two-piece structure provided with a wall-shaped holder member 18 a extending in the width direction (direction perpendicular to the cylinder array direction) of the cylinder head 1 , and a cap member 18 b to be combined with the holder member 18 a at a lower end part thereof, and a structure in which a holder member 18 a, a cap member 18 b, and a plurality of fixing bolt members 18 c to be attached to the members 18 a and 18 b so as to penetrate the members 18 a and 18 b are combined with each other are used for these retaining members 11 a to 11 c.
Of the above members, each of the holder members 18 a has the same structure, and as shown in FIG. 3 , an intake rocker shaft retaining hole 20 a and an exhaust rocker shaft retaining hole 20 b arranged in the lateral direction with a predetermined interval between them are formed in the middle stage on both sides of each holder member 18 a. On a top surface of the holder member 18 a, an arcuate attaching seat 21 is formed at a position between the intake rocker shaft retaining hole 20 a and the exhaust rocker shaft retaining hole 20 b and closer to the hole 20 b. On an undersurface of the holder member 18 a, a semicircular journal bearing surface 22 is formed at a position between the intake rocker shaft retaining hole 20 a and the exhaust rocker shaft retaining hole 20 b and closer to the hole 20 b. The entire undersurface of the holder member 18 a except for the bearing surface 22 is used as a cap attaching seat 23 .
For example, a plate-like member having an arcuate recession at a central part thereof is used as the cap member 18 b. A semicircular journal bearing surface 25 is formed at the central part on a top surface of the cap member 18 b, and the entire top surface except for the bearing surface 25 is used as a cap attaching surface 26 . Incidentally, flat undersurface parts on both sides on the undersurface of the cap member 18 b between which the journal bearing surface 25 is interposed are used as a module installation seat surface 27 .
Each of the foremost holder member 18 a and cap member 18 b has, unlike the other members, a pair of leg parts 29 formed so as to externally extend on both sides thereof. A journal bearing surface 22 , a cap attaching seat 23 , a journal bearing surface 25 , a cap-attaching surface 26 , and a seat surface 27 are also formed on the pairs of the leg parts 29 .
Incidentally, through holes 28 in which head bolts (not shown) are inserted are formed in the leg parts 29 . A sensor attaching part 30 is formed on the holder member 18 a arranged at the backmost position. In the sensor attaching part 30 , as shown in FIGS. 3 and 4 , a structure in which a cylinder part 31 a extending from the intake rocker shaft retaining hole 20 a toward the backmost position is formed, and a fan-shaped sensor attaching boss 31 b is formed at a distal end of the cylinder part 31 a is employed.
In the respective intake rocker shaft retaining holes 20 a, as shown in FIGS. 2 and 3 , a control shaft 14 (constituted of a hollow member) serving also as the intake side rocker shaft is rotatably inserted so as to allow the shaft 14 to extend from the foremost retaining member 11 a to the backmost retaining member 11 c. The exhaust side rocker shaft 34 (constituted of a hollow member) is inserted in the respective exhaust rocker shaft retaining holes 20 b so as to allow the shaft 34 to extend from the foremost retaining member 11 a to the backmost retaining member 11 c. Likewise, a support shaft 35 (constituted of a hollow member) is fitted in the respective attaching seats 21 so as to allow the shaft 35 to extend from the foremost retaining member 11 a to the backmost retaining member 11 c.
Likewise, the camshaft 15 is arranged between the respective journal bearing surfaces 22 and the journal bearing surfaces 25 so as to allow the shaft 15 to extend from the foremost retaining member 11 a to the backmost retaining member 11 c. A plurality of journals 37 (shown in FIG. 6 ) formed on the shaft part of the camshaft 15 are received between the journal bearing surfaces 22 and the journal bearing surfaces 25 , thereby rotatably supporting the camshaft 15 .
Incidentally, each of parts of the camshaft 15 between the respective journals 37 (between the cylinders) includes a cam group constituted of an intake cam 38 a arranged in the center and (two) exhaust cams 38 b arranged on both sides.
The variable valve operating mechanism 13 (intake side) is attached to parts of the support shaft and the control shaft between the above-mentioned holder members 18 a, and the rocker arm mechanism 17 (exhaust side) is attached to parts of the exhaust rocker shaft 34 (for each cylinder).
Here, the respective mechanisms will be described below. As shown in FIGS. 3 and 5 , a valve drive mechanism of a type called a swing cam type in which a swing cam 50 is used, for example, a mechanism in which a rocker arm 40 , a swing cam 50 , and a center rocker arm 60 are combined with each other is used as the variable valve operating mechanism 13 .
The above elements will be described below. As the rocker arm 40 , the one having a bifurcate arm shape is used. Specifically, the rocker arm 40 is provided with a pair of L-shaped rocker arm pieces 43 having needle rollers 41 rotatably provided between one ends of the pieces 43 and having adjust screw sections 42 serving as valve drive sections provided at the other ends of the pieces 43 .
Further, a part of the control shaft 14 between the holder members 18 a is swingably inserted in a pair of support holes 44 formed in intermediate parts of the respective rocker arm pieces 43 . Further, the needle rollers 41 are arranged on the support shaft 35 side, and the pair of adjust screw sections 42 are arranged on the opposite side of the support shaft 35 .
As shown in FIGS. 3 and 5 , a structure in which a supporting boss 52 having a cylindrical shape is provided at one end of an arm section 51 , a cam surface 53 extending in the vertical direction is provided at the other end of the arm section 51 , and a slide roller 54 is rotatably embedded in the lower part of the arm section 51 in such a manner that the outer circumferential surface thereof is exposed from the lower side is used for the swing cam 50 .
Incidentally, reference numeral 54 a denotes a shaft member for supporting the slide roller 54 . A part of the support shaft 35 between the holder members 18 a is swingably fitted in the supporting boss 52 . As a result of this, the cam surface 53 at the distal end of the arm section 51 is in rolling contact with the needle rollers 41 .
A pusher receiving rib 56 is protruded from an upper part of the supporting boss 52 . A pusher 57 having, for example, a piston structure is combined with the rib 56 at a lower position of the rib 56 in an inclined posture. This pusher 57 is supported by fitting a C-shaped leg section 58 formed on the side part thereof on a part of the exhaust side rocker shaft 34 .
Incidentally, an installation seat 59 is formed at a lower part of the pusher 57 . A structure is made such that when the variable valve unit 4 is attached to the cylinder head 1 by means of the installation seat 59 , an energizing force is imparted to the swing cam 50 (this is because when the installation seat 59 is provided on the cylinder head 1 , the pusher is rotationally displaced using the rocker shaft 34 as a fulcrum).
The center rocker arm 60 is, as shown in FIGS. 3 and 5 , constituted of an L-shaped part arranged at a position surrounded by the intake cam 38 a, slide roller 54 , and control shaft 14 .
The center rocker arm 60 includes a relaying arm section 61 extending toward the slide roller 54 above, and a fulcrum arm section 62 extending toward a part immediately below a part of the control shaft 14 located at a lateral position.
An inclined surface 65 for controlling the movement of the swing cam 50 is formed on a distal end surface of the relaying arm section 61 . This inclined surface is a flat surface having a lower part on the control shaft 14 side and a higher part on the rocker shaft 34 side. Further, a slide roller 63 is supported at an intermediate part at which both the arm sections 61 and 62 intersect each other so as to be rotatable in the same direction as the intake cam 38 a.
Further, in the relaying arm section 61 interposed between the intake cam 38 a and the swing cam 50 , the slide roller 63 is in rolling contact with the cam surface of the intake cam 38 a, and the inclined surface 65 of the relaying arm section 61 is bumped against an outer circumferential surface of the slide roller 54 of the swing cam 50 . As a result of this, the displacement of the intake cam 38 is transmitted to the swing arm 50 through the relaying arm section 61 .
Further, a support pin 66 is flexibly supported on the fulcrum arm section 62 by means of a pin 67 . A distal end of the support pin 66 is rotatably inserted in a through hole 68 formed on the lower side of the control shaft 14 in a direction perpendicular to the axial direction, whereby the control shaft 14 is caused to support the center rocker arm 60 .
By virtue of this support, when the control shaft is 14 rotationally moved, the rocker arm 60 that swings around the pin 67 (end of the support pin 6 ) serving as a fulcrum can move in a direction intersecting the camshaft 15 (in the lead angle direction or the lag angle direction) while changing the position at which the rocker arm 60 is in rolling contact with the center intake cam 38 a.
In this movement, the opening/closing timing and the valve lift amount of the intake valve 8 a can be simultaneously and continuously varied. That is, the upper part of the cam surface 53 is a base circle section (formed by, for example, an arcuate surface having the axis of the support shaft 35 as a center thereof), and the lower part of the cam surface 53 is a lift section (formed by, for example, an arcuate surface having the same shape as the cam shape of the lift region of the intake cam 38 a ) continuing from the base circle section.
When the slide roller 63 of the center rocker arm 60 moves in the lead angle direction or the lag angle direction of the intake cam 38 a, the posture of the swing cam 50 is changed, and the region of the cam surface 53 in which the needle rollers 41 move is changed.
In other words, the ratio of the base section to the lift section in which the needle rollers 41 travel is changed. A change in the ratio of the base section to the lift section accompanied by a change in the phase in the lead angle direction and a change in the phase in the lag angle direction continuously changes the valve lift amount of the intake valve 8 a while largely changing the opening/closing timing of the intake valve 8 a. In this case, the valve-closed period is more changed than the valve-opened period. This is output from the rocker arm 40 as the valve drive output. At this time, in order to prevent the alignment of the slide roller 54 with the inclined surface 65 from being shifted, a pair of guide walls 51 b extending from wall sections 51 a sandwiching the slide roller 54 from both sides (in the width direction) to both sides of the distal end of the relaying arm section 61 bumping against the slide roller 54 are formed on the wall sections 51 a as shown in FIGS. 3 and 5 .
Specifically, the guide walls 51 b are provided in such a manner that they cover the contact point at which the slide roller 54 of the swinging swing cam 50 and the inclined surface 65 of the center rocker arm 60 are in contact with each other. As a result of this, the center rocker arm 60 is prevented from being shaken around the support pin 66 serving as a fulcrum. To the part of the control shaft 14 in which the support pin 66 is inserted, an adjustment mechanism 70 is attached as shown in FIGS. 3 and 5 . In the adjustment mechanism 70 , a structure is employed in which a threaded hole 71 continuing from the through hole 68 and opening upwardly is formed at, for example, the part of the control shaft 14 , and, for example, a screw member 73 having a slot 72 for screw-driving at a head part thereof is screwed into the threaded hole 71 so that it can be advanced or retreated.
In other words, the adjustment mechanism 70 has a structure in which the protrusion amount of the support pin 66 is changed by a rotating operation of the screw member 73 , whereby the rolling contact position of the slide roller 63 is changed. Further, a change in the rolling contact position of the slide roller 63 changes the posture of the center rocker arm 60 and the posture of the swing cam 50 , thereby adjusting the valve opening/closing timing and the valve lift amount (each of which is a valve characteristic). The screw member 73 is locked by a locknut 74 . Incidentally, a reference numeral 75 denotes a notch forming a seat surface of the lock nut 74 .
A proximal end part of an arm member 78 extending in the radial direction of the control shaft 14 , i.e., in this case, extending upwardly is fixed (by a screw) to an end of the control shaft 14 protruding from the foremost holder member 18 a by means of, for example, a screw member 77 as shown in FIGS. 2 and 3 . Rotational movement necessary for continuous control of the valve characteristic is input from the end of the arm member 78 .
In the rocker arm mechanism 17 (exhaust side), a structure is employed in which a pair of rocker arms 80 are rotatably assembled on both sides of the leg section 58 of the pusher 57 at a part of the rocker shaft 34 , as shown in FIGS. 3 and 5 .
Specifically, each of the rocker arms 80 has a support hole 81 at an intermediate part thereof, has a roller member 82 serving as a contact piece at an end thereof, and has an adjusting screw section 83 serving as a valve drive section at the other end thereof.
Then, the part of the rocker shaft 34 between the holder member 18 a and the leg section 58 (pusher 57 ) is swingably inserted in the support holes 81 of the rocker arms 80 . Each of the roller members 82 is arranged on the exhaust cam 38 b side and the adjust screw section 83 is arranged on the opposite side. That is, each rocker arm 80 is in a state where it can be combined with the exhaust valve 9 a.
As shown in FIGS. 3 , 6 , and 7 , the fixing bolt member 18 c is inserted from the seat surface 90 formed on the top surface of each holder member 18 a directly above the rocker shaft 34 . The fixing bolt member 18 c linearly penetrates (skewers) a central part of the rocker shaft 34 in the radial direction, a wall part on the support shaft 35 side (one side of the camshaft 15 ), the support shaft 35 being adjacent to the camshaft 15 , and the cap part of the cap member 18 b on the rocker shaft 34 side.
The fixing bolt 18 c is obliquely inserted from each seat surface 21 a formed in the upper surface of the support shaft 35 arranged at the highest position. As a result of this oblique insertion, the wall part between the rocker shaft 34 and the control shaft 14 , the wall part between the camshaft 15 and the control shaft 14 , and the cap part of the cap member 18 b on the control shaft 14 side are obliquely and linearly penetrated (skewered) by the fixing bolt 18 c.
However, reference numerals 92 and 93 denote bolt insertion holes (only a part of them is shown in FIG. 3 ), which are formed linearly or obliquely linearly in the holder member 18 a and the cap member 18 b. Incidentally, as for the number of the fixing bolt members 18 c to be inserted obliquely, one bolt member 18 c is used in the holder member 18 a and the cap member 18 b arranged at the foremost part or the backmost part, and two bolt members 18 c are used in the holder member 18 a and the cap member 18 b arranged between the cylinders to which a load heavier than that applied to the member 18 a and 18 b arranged at the foremost part or the backmost part is applied (because a load incidental to the variable valve motion is applied to the member 18 a and 18 b from both sides).
Furthermore, the shaft displacement detection sensor 16 for detecting the rotational displacement of the control shaft 14 is detachably attached to the sensor attaching boss 31 b provided on the backmost holder member 18 a by means of, for example, screws.
That is, in the variable valve unit 4 , the variable valve operating mechanism 13 , the shaft displacement detection sensor 16 , the rocker arm mechanism 17 of the exhaust side, the camshaft 15 , and the adjustment mechanism 70 are modularized into a structure by the method in which each part is attached to a frame-like structure having high rigidity constituted of the shafts 14 , 34 , and 35 and the retaining members 11 a to 11 c.
Accordingly, each of the shafts 14 , 34 , and 35 plays a role of the frame, and hence the retaining members 11 a to 11 c can be provided solely at positions where they are required without increasing the size, and the weight of the variable valve unit 4 itself can be minimized.
Further, the shaft displacement detection sensor 16 is positioned so as to be protruded from the cylinder head 1 and the rocker cover 3 to the outside by appropriately setting in advance the cylinder part 31 a and the sensor attaching boss 31 b. Thus, when the variable valve unit 4 is accommodated in a space between the cylinder head 1 and the rocker cover 3 , the entire assembly other than the shaft displacement detection sensor 16 can be accommodated in the space between the cylinder head 1 and the rocker cover 3 , and only the shaft displacement detection sensor 16 is exposed to the outside.
By virtue of such modularization, the variable valve unit 4 becomes a structure in which cylinder-to-cylinder variation can be adjusted singly. Thus, in the variable valve unit 4 , cylinder-to-cylinder variation and the sensor output can be adjusted before the mechanism 4 is attached to the cylinder head 1 . As a result, in the variable valve unit 4 , cylinder-to-cylinder variation and the sensor output is adjusted before the mechanism 4 is attached to the cylinder head 1 , and then the mechanism 4 is attached to the cylinder head 1 as shown in FIGS. 2 and 7 .
This point will be specifically described below. It is recommended for the variable valve unit 4 , modularized before it is attached to the cylinder head 1 , to be subjected to adjustment of cylinder-to-cylinder variation and the sensor output on a sub-line separate from the mainline for assembling engines by using a simulation system in which a cylinder head of an engine is simulated.
For example, a modularized variable valve unit 4 is attached to a simulated cylinder head, and a simulated drive apparatus (not shown) is also attached thereto. It is only required to adjust the opening/closing timing and the valve lift amount so as to be uniform and appropriate in the respective cylinders with respect to the target lift by advancing or retreating the screw member 73 of the adjustment mechanism 70 of each cylinder, and attaching the shaft displacement detection sensor 16 so that a signal output conforming to the target lift can be obtained.
The variable valve unit 4 that has been adjusted is transferred by using a jig or a transportation apparatus (both are not shown) as it is so that the adjustment can be maintained so as to be set at a regular position of an actual cylinder head 1 (assembly of a cylinder block is already finished) on the main line for assembling engines, i.e., at module installation seats 94 and 300 (seat surfaces for receiving the seat surface 27 : shown in FIGS. 5 to 7 ), for example, already formed on the top surface 1 y.
Specifically, both the side parts (including the leg parts 29 ) of the cap member 18 b are placed on the module installation seats 94 and 300 , and the threaded part 18 d (formed only at each distal end) of each of the fixing bolt members 18 c on both sides protruding from parts near both sides of the camshaft 15 is screwed into each of the threaded holes 18 e (shown in only FIG. 7 ) formed in the module installation seats 94 and 300 .
As a result, the already adjusted variable valve unit 4 is attached to the top surface 1 y of the cylinder head 1 on the main line. Incidentally, each adjust screw section 42 of the intake side rocker arm 40 is arranged at a stem end of the intake valve 8 a. Each adjust screw section 83 of the exhaust side rocker arm 80 is arranged at a stem end of the exhaust valve 9 a.
The installation seat 59 bumps against the installation seat 1 c (shown in FIGS. 1 and 5 ) formed on the inner surface of the peripheral wall 1 a of the cylinder block 1 , the entire pusher 57 is supported by the leg section 58 , and the swing cam 50 is energized in a direction in which a distal end thereof is forced down.
On the other hand, as shown in FIGS. 1 to 3 , a driving source apparatus for driving the variable valve operating mechanism 13 , for example, an electrically-driven actuator unit 95 (corresponding to an actuator) is installed at the foremost part of the cylinder head 1 .
The electrically-driven actuator unit 95 includes a motor section 96 of a lateral (width direction of the cylinder head 1 ) type arranged outside the peripheral wall 1 a of the cylinder head 1 , a reduction gear section 97 (for reducing the motor output) connected to the front part of the motor section 96 , and a screw shaft 99 connected to the output section of the reduction gear section 97 through a universal joint 98 . These are formed into one part as a driving unit.
This electrically-driven actuator unit 95 is attached to the cylinder head 1 in a direction in which the axis thereof intersects the variable valve unit 4 by fixing the leg section 97 b formed on the casing 97 a of the reduction gear section 97 to the top surface 1 y of the cylinder head 1 or the rocker cover attaching seat 1 b by means of bolts.
In this way, the motor section 96 is caused to protrude toward the outside of the cylinder head 1 , and the screw shaft 99 is caused to extend to the arm member 78 end (variable arm mechanism 13 ) side. That is, the screw shaft 99 extends to the opposite side of the motor section 96 .
Incidentally, a part of the peripheral wall 1 a or the rocker cover 3 at which the electrically-driven actuator unit penetrates the wall 1 a or the cover 3 is formed into a fan-shaped opening.
A nut member 100 is screw-fitted on the screw shaft 99 so that it can be advanced or retreated. The nut member 100 is constituted of a pin-shaped member having a flange part 100 c at one end thereof, and having a threaded through hole 100 a formed in the axial direction thereof at an axis part thereof. The thread hole 100 a penetrates the nut member 100 in the diameter direction. The threaded hole 100 a of the nut member is screw-fitted on the screw shaft 99 so that it can be advanced or retreated. This nut member 100 is attached to the distal end of the arm member 78 , and the control shaft 14 can be driven by the electrically-driven actuator unit 95 .
That is, the nut member 100 is rotatably fitted in a support cylinder 78 a formed at the distal end of the arm member 78 (variable valve unit 4 ) and, for example, a C-shaped clip member 100 b is fitted on the distal end of the nut member 100 so as to allow it to prevent the nut member 100 from slipping off the support cylinder 78 a, thereby attaching the nut member 100 to the arm member 78 .
The part of the screw shaft on both sides of the nut member 100 penetrates a pair of elongated holes formed on both sides of the peripheral wall of the support cylinder 78 a and extending in the circumferential direction. When the motor section 96 is operated, the screw shaft 99 is rotated, and the nut member 100 is moved along the screw shaft 99 which is swingable. As a result, the arm member 78 is swung, and the control shaft 14 is rotated. In other words, by the driving of the electrically-driven actuator unit 95 , the opening/closing timing of the intake valve 8 a and the valve lift amount can be continuously controlled.
As shown in FIG. 2 , the rocker cover 3 is formed into a box-like shape in accordance with the shape of the cylinder head 1 . Further, at parts of the peripheral edge of the rocker cover corresponding to the penetration position of the shaft displacement detection sensor 16 and the motor section 96 a , fan-shaped notch parts 3 a (only a notch part for the sensor is shown in FIG. 4 ) for allowing the shaft displacement detection sensor 16 or the motor section 96 a to penetrate the rocker cover while sealing the penetration parts are formed.
This rocker cover 3 is set on the rocker cover attaching seat 1 b formed at the peripheral edge of the cylinder head 1 as shown in FIGS. 1 and 4 . As a result, of the units and devices to be mounted on the cylinder head 1 , the shaft displacement detection sensor 16 and the motor section 96 are exposed to the outside of the rocker cover 3 , and the remaining variable valve unit 4 , and the greater part of the electrically-driven actuator unit 95 are accommodated in the closed space between the cylinder head 1 and the rocker cover 3 .
The shaft displacement detection sensor 16 is exposed to the outside of the rocker cover 3 , and hence the shaft displacement detection sensor 16 can be replaced from outside while the rocker cover 3 is closed.
As described above, the variable valve unit 4 becomes a structure in which cylinder-to-cylinder variation and the sensor output can be adjusted singly by modularizing the camshaft 15 , the shaft displacement detection sensor 16 , and the adjustment mechanism 70 . As a result of this, the cylinder-to-cylinder variation adjustment and the sensor output adjustment, which require troublesome operations, can be performed at a place separate from the main line for assembling engines.
Accordingly, the only work required on the main line for engine assembly is that for attaching a variable valve unit 4 for which the cylinder-to-cylinder variation adjustment and the sensor output adjustment have been finished to a cylinder head 1 on the main line. The cylinder-to-cylinder variation adjustment work and the troublesome work for attaching the shaft displacement detection sensor 16 , which are regarded as factors in stagnation, are made unnecessary.
Therefore, the productivity of engines can be improved. Moreover, the shaft displacement detection sensor 16 is exposed to the outside of the rocker cover ( FIG. 4 ), and hence, in a completely assembled engine or an engine completed as a product, even when maintenance of the shaft displacement detection sensor 16 is required, it is easily possible to cope with the requirement.
Particularly, the shaft displacement detection sensor 16 can be replaced from outside the rocker cover 3 , and the replacement work of the sensor 16 can therefore be easily performed. Even when replacement of the shaft displacement detection sensor 16 is required after the engine is completed as a product, it is possible to quickly cope with the requirement.
Furthermore, the shaft displacement detection sensor 16 for detecting the rotational displacement is arranged at one end of the control shaft 14 , whereby the rotational displacement can be directly detected, adjustment accuracy can be enhanced, and accurate control can be enabled.
The other end of the control shaft 14 is coupled to the electrically-driven actuator unit 95 , whereby even the elastic torsion of the control shaft 14 caused by valve lift reaction force can be detected as the rotational displacement, and accurate control is enabled.
Moreover, in the variable valve unit 4 , modularization including the shaft displacement detection sensor 16 and the arm member 78 , which is an actuator coupling member, is enabled, and hence the number of assembly man-hours can be reduced.
Furthermore, by employing the structure in which the holder members 18 a for holding the one side of the camshaft 15 in the diametric direction, the variable valve operating mechanism 13 , the adjustment mechanism 70 , and the shaft displacement detection sensor 16 , the cap members 18 b for holding the remaining one side of the camshaft 15 , and the fixing bolt members 18 c penetrating the holder members 18 a and the cap members 18 b are combined with each other as the retaining members 11 a to 11 c, the fixing bolt members 18 c used for attachment to the cylinder head 1 can also be used as parts for modularization as they are, and the work for modularization and the adjustment work are performed on the basis of the fixing bolt members 18 c set as the standard, and hence highly accurate modularization of the variable valve unit 4 and highly accurate adjustment can be performed.
Next, a valve unit of an internal combustion engine according to a second embodiment of the present invention will be described below with reference to FIG. 8 . Incidentally, a configuration having the same function as the first embodiment will be denoted by using the same reference symbols as those in the first embodiment, and explanation of them will be omitted.
This embodiment differs from the first embodiment in including a variable valve operating mechanism 200 in place of the variable valve operating mechanism 13 . The other part of the structure may be identical to the first embodiment. The point of the second embodiment different from the first embodiment will be specifically described below.
FIG. 8 is a cross-sectional view showing an engine 10 of this embodiment. As shown in FIG. 8 , in this embodiment, the engine is provided with the variable valve operating mechanism 200 in place of the variable valve operating mechanism 13 . The variable valve operating mechanism 200 has a function of adjusting the opening/closing operation of an exhaust valve 9 a and not that of an intake valve 8 a.
The variable valve operating mechanism 200 has a structure in which the intake side and the exhaust side are replaced with each other in the structure of the variable valve operating mechanism 13 described in the first embodiment (accordingly, the configuration having the same function as the first embodiment is denoted by the same reference symbols).
In the variable valve operating mechanism 200 , the control shaft 14 doubles as a rocker shaft of the exhaust side. Further, on the intake side, an intake rocker shaft 201 is provided in place of the control shaft 14 .
An intake valve rocker arm (not shown) is attached to the intake rocker shaft 201 . The intake valve rocker arm drives (opens/closes) the intake valve 8 a. A structure for driving the intake valve 8 a in this embodiment may be a mirror image structure of the structure for driving the exhaust valve 9 a in the first embodiment.
Even when the variable valve operating mechanism 200 has a structure in which driving of the exhaust valve 9 a can be adjusted as in this embodiment, the same advantage as in the first embodiment can be obtained.
Incidentally, the present invention is not limited to the firs and second embodiments described above, and may be variously modified and implemented within the scope not deviating from the gist of the present invention. For example, the variable valve operating mechanism of the swing cam type is described as an example in the first and second embodiments. The present invention is not limited to this, and a variable valve operating mechanism of another structure may be used.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. | A valve unit of an internal combustion engine is accommodated in a space between a cylinder head and a rocker cover. The valve unit comprises a camshaft, a variable valve operating mechanism, a sensor, and a retaining member. The camshaft is provided with a cam for each cylinder. The variable valve operating mechanism receives a displacement of the cam, outputs a valve drive output, and continuously variable-controls the valve drive output in accordance with a rotational displacement of a control shaft provided substantially in parallel with the camshaft. The sensor detects the rotational displacement of the control shaft. The retaining member retains the camshaft, the variable valve operating mechanism, and the sensor. The retaining member expose the sensor to the out side of the rocker cover thereby to fix the camshaft, the variable valve operating mechanism, and the sensor to the cylinder head. | 5 |
TECHNICAL FIELD OF THE INVENTION
The field of this invention is structural polymeric composites. More particularly, the present invention pertains to polymeric matrices and laminated polymeric composites containing particulate by-products of corn or fibrous components of corn.
BACKGROUND OF THE INVENTION
Interest in natural products as renewable raw materials for industrial products has greatly intensified in the past fifteen years. Over-production in agricultural markets has led to an abundant supply of renewable resources and has created a driving force to develop new markets for these products. Ground sunflower stalks have been used as a raw material for particle board. However, due to low internal bond strength however, it was concluded that sunflower stalks made an acceptable particle board only for interior applications. Bamboo has also been utilized as a reinforcement in laminated structures. Tensile, flexure and impact strengths of bamboo fiber-reinforced plastic were measured and the bamboo composites were deemed commercially viable for structural applications.
About 9% of the total corn crop grown in the United States is currently used for non-food, industrial applications. Corn products produced by both wet milling and dry milling processes have continued to find new uses in non-food applications. The starch produced by wet milling has been successfully used as a filler for biodegradable plastics and styrofoam. The corn flour produced by dry millers has been used in numerous industrial applications including various building materials such as gypsum board, fiberboard and ceiling tiles, biodegradable plastics and paper.
In each of these applications, the corn starch or flour serves as a particulate constituent in what is essentially a composite material. In the manufacture of gypsum board, acid modified corn flour was gelatinized in-situ during drying of the board and served to control the rate of water loss during the drying. The soluble carbohydrates also aided in controlling the rate of crystallization of the gypsum, creating a strong bond between gypsum and its paper liner.
The existing uses of corn as a constituent of composites require processing of the corn (e.g., forming meal or starch). Further, those uses typically employ those parts of corn that are used for food production (e.g., kernels, cobs). There continues to be a need for composite materials that contain non-food components of corn and which composites can be made without preprocessing those components.
BRIEF SUMMARY OF THE INVENTION
The present invention provides compositions and methods relating to structural composites containing fibrous components of corn. A structural composite of the present invention is a laminated polymer composite that contains a fibrous component of a corn plant and a polymeric resin.
A laminated polymeric structural composite can be prepared by mixing a fibrous component of corn and a polymeric matrix and laminating the mix. The present invention also provides laminated structural composites formed by such processes.
Composites of the present invention have mechanical properties equal or greater than those of wood-based composites such as oriented strand board. An advantage of using fibrous corn components (e.g., husks) is that such components are readily available from what is considered a waste product of corn processing. The use of otherwise discarded husks without any additional processing, provides enormous economic savings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, which form a portion of the specification:
FIG. 1 shows the impact strength as a function of volume fraction of a corn starch additive in polyester;
FIG. 2 shows the normalized impact energy of a corn-based laminated polymer composite (cornboard) compared to laminated composites made using wood-based reinforcements (Hardboard, OSB-1, OSB-2); and
FIG. 3 shows the elastic modulus as a function of volume fraction of corn starch in a polyester;
FIG. 4 is a plan view of a quasi-unidirectional laminated composite according to an embodiment of the present invention;
FIG. 5 is a plan view of a quasi-isotropic laminated composite according to another embodiment of the present invention; and
FIG. 6 is a cross-sectional view of the laminated composite according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In one aspect, the present invention provides a structural polymeric composite that comprises a corn-based reinforcement. The corn-based reinforcement is a fibrous part of a corn plant such as the husks or stalks. A structural composite is a laminated polymer where the fibrous corn element serves as a primary reinforcement.
Any polymer matrix suitable for structural composites can be used to form a composite. Exemplary and preferred polymer matrices are epoxy resin, phenol-formaldehyde, polyester, polypropylene, polyethylene and the like. The selection of a particular matrix for inclusion in a composite of the present invention depends to a large extent on the desired use of the formed composite. By way of example, composites formed with epoxy resins are suitable for decorative-structural elements (e.g., counter-tops) while composites formed with phenol-formaldehyde or polyesters are suitable for mechanical-structural uses where mechanical strength is important. An especially preferred polymer matrix is phenol-formaldehyde, which is used to form oriented strand board.
A laminated polymer composite is prepared by mixing the fibrous corn component with the polymer matrix and then laminating the mixture. The laminated polymer composite can be a quasi-unidirectional laminate (FIG. 4) where the fibers of the fibrous component are aligned or a quasi-isotropic laminate (FIG. 5) where the fibrous component is randomly aligned relative to the plane of the laminate.
To form a quasi-unidirectional laminate, a stack is formed by alternately layering the fibrous component with layers of the polymer matrix. The polymer matrix can be added in the form of a liquid or powder. When forming a stack of fibrous components, a liquid matrix is preferred.
The fibrous component is corn husks or corn stalks. Corn husks are preferred because they can be used directly without any preparatory steps. Where corn stalks are used, it is necessary to remove pith from the stalk prior to mixture with the polymer matrix.
Composites can also be made simply by mixing husks with powdered or liquid polymer matrix. Typically, the husks and polymer are mixed in blender. After mixing (or forming the stack) the husk/polymer matrix mix is laminated using standard procedures well known in the art.
Lamination is accomplished by compressing the mixture under pressure at an elevated temperature. Both the temperature and pressure can vary over a wide range. The only limitations on temperature are 1) temperature must be sufficiently high to allow for compression and 2) temperature must not exceed the temperature at which degradation of the husk or polymer matrix occurs. Hot compressing typically occurs with temperatures of from about 50° C. to about 100° C. and, more preferably from about 70° C. to about 90° C. Temperature should be kept below 120° C. Pressure is typically from about 40 to about 60 psi.
Compression continues for a period of time suitable to compress the mixture to a desired density. Typically, compression continues, as is well known in the art, until there are no visible sign of porosity in the formed composite. Compression time will vary with compression temperature and pressure. Generally, compression time decreases as pressure and temperature increase. Where the temperature is about 80° C., compression or curing time is about 1 hour.
To facilitate handling of the formed composite, the mixture or stack is typically placed in a mold coated with a releasing agent. After compression, the composite is cooled and removed from the mold. The composite can then be cut and shaped as desired. Composites of any desired thickness can be prepared. To avoid overheating of the inner most portions of the composite, it is preferred to maintain thickness during compression at less than about 25 mm. Composites of greater thickness can be prepared by forming thinner composites and then compressing those composites together. A detailed description of the preparation of laminated polymer composites using corn husks can be found hereinafter in Example 2.
The following Examples illustrate preferred embodiments of the present invention and are not limiting of the specification and claims in any way.
EXAMPLE 1
Polymeric Matrix
To make starch filled composites, a specific volume fraction of starch particles was mixed thoroughly with the chosen polymer and then poured into silicon rubber or metal molds. For these studies, orthophthalic polyester (Superior Co.) was chosen for the matrix. The starch-polyester composites were allowed to cure for 24 hrs at room temperature and then post cured at 40° C. for another 24 hrs to insure full crosslinking. The processing temperatures are well below the gelatinization temperature of starch, so that the granule integrity was maintained. The starch/polyester was molded into circular 102 mm diameter ×6 mm thick discs for impact testing or into 6 mm thick dog-bone coupons (125 mm gage length) for tensile testing. Impact and tension tests were used to establish the baseline properties of the corn reinforced composite materials.
A Dynatup model 8250 drop tower was used to measure the impact resistance of the materials. A 12 mm diameter hemispherical instrumented striker impacts the center of a specimen that is circumferentially clamped over a 76 mm hole in a support base. Data is collected through the duration of the impact event to assess the load at the onset of damage, the peak impact load, and the energy absorption during the impact event. Results of impact tests on the corn-starch reinforced materials are shown in FIG. 1. Significant improvement in absorbed energy was found for starch content greater than 5% volume fraction.
Tensile tests were used to determine the elastic properties as well as the ultimate strengths. Tensile specimens were tested using a standard Instron machine with a 5000 lb load cell and a clip-gage extensometer. The elastic moduli measured from tensile tests of starch reinforced polyesters are shown in FIG. 3. As the starch content was increased, the elastic modulus was also found to increase reaching a maximum value between 20 and 30% volume fraction. Overall, an increase in modulus of about 20% was achieved.
EXAMPLE 2
Laminated Polymer Composite
Two types of husk laminates were made. Both types used an epoxy resin as the matrix. The first was a quasi-unidirectional lay-up in which the fibers 20, 22 of the husks 24, 26 were all aligned in the same general direction (FIG. 4). These laminates were used to obtain unidirectional mechanical test specimens so that upper and lower bounds could be obtained on tensile strength and stiffness. The second type of laminate was a quasi-isotropic lay-up in which the husks 28, 30 were chopped into short segments (up to 50 mm in length) and randomly distributed in the plane of the laminate (FIG. 5).
Both types of laminates were manufactured by hot pressing using a Tetrahedron MTP-14 laboratory hot press. A rectangular aluminum mold (203 mm×203 mm) was fabricated with a matching upper caul plate. The lay-up sequence was similar to that used in the aerospace industry. The mold was first coated with a releasing agent and then a gel coat was placed on the mold surface. The first layer of husks 32 were then placed onto the mold surface and coated with resin 34. Another layer of husks 36 was then deposited onto the first and coated with more resin 38. This sequencing was continued until the laminate thickness reached 12-13 mm. Next, a peel ply was placed on top of the laminate, followed by four plies of bleeder cloth and a release film.
The upper caul plate was then placed on top of the lay-up and the mold was transferred to the hot press. The cure schedule for these laminates called for maintaining 50 psi compaction pressure during cure at 80° for one hour. During curing approximately 50% compaction in thickness occurs. Final thicknesses were measured to be between 6 and 7 mm.
The impact response of quasi-isotropic husk laminates was measured as described in Example 1. A comparison of the results to two grades of OSB (oriented strand board) and masonite (hardboard) is shown in FIG. 2. Both the OSB and hardboard were fabricated using a phenol-formaldehyde resin, while the corn husk reinforced board used an epoxy matrix. The results have been normalized with respect to the plate thickness. The cornboard was found to be significantly more resistant to impact than either of the OSB grades and it compared favorably with the hardboard.
Table 1, below, summarizes the results of tensile tests on quasi-unidirectional husk laminates. Both longitudinal and transverse specimens were tested.
TABLE 1______________________________________ Elastic Modulus Tensile StrengthTest Direction (GPa) (MPa)______________________________________Longitudinal to the husk 3.37 32Transverse to the husk 1.97 15______________________________________
The data demonstrated that longitudinal reinforcement showed the highest strength and stiffness. The ratio of longitudinal to transverse moduli and strength was 1.71 and 2.13, respectively. The data in Table 2, below, compares the properties of the husk-reinforced epoxy composite with OSB particle board with a phenol-formaldehyde matrix.
TABLE 2______________________________________ Elastic Tensile Modulus StrengthTest Direction (GPa) (MPa)______________________________________Longitudinal Corn Husk Reinforced 3.37 32EpoxyAspen Planar Shaving Particleboard 2.5 25______________________________________
The data show that both the modulus and strength of longitudinal laminates exceeded those of particle board. | A structural polymeric composite containing corn-based material is provided. In one embodiment, a polymeric composite is a laminated polymeric composite that contains a fibrous component of corn. A method of making a structural composite using corn-based material is also provided. | 1 |
This is a continuation of application Ser. No. 07/558,132, filed Jul. 26, 1990 now abandoned.
FIELD OF THE INVENTION
This invention relates to a coupling for connecting elements in an automotive exhaust system. More particularly, it relates to a flexible decoupler for connecting the engine manifold to an exhaust pipe section.
BACKGROUND OF THE INVENTION
In the operation of an automotive vehicle the engine creates torque during periods of acceleration and deceleration. For engines which are aligned so that the crankshaft extends along the length of the vehicle, conventional connections between the engine manifold and the exhaust system are able to absorb the torque without problems. For engines arranged along a transverse axis, however, the torque stresses the normally rigid connection between the engine manifold and the exhaust system, which can eventually cause fatigue cracking of the engine manifold.
To prevent the transmission of torque forces to the engine manifold, it is necessary to replace the normally rigid connection between the engine manifold and the exhaust system with one that does not transmit the torque forces. This typically has been accomplished through use of a ball and socket joint, which allows the angle between the manifold and the exhaust system to vary without transmitting undesirable stresses to the engine manifold. Although this arrangement has been successful in preventing fatigue cracking of the manifold, the joint is not able to contain the exhaust gases, allowing them to leak out into the atmosphere without passing through the catalytic converter. This creates the potential danger of leaked exhaust gases entering the passenger compartment of the vehicle.
Further drawbacks in conventional coupling arrangements are the lack of thermal insulation in the connection between the engine manifold and the exhaust system and the high cost of such connectors.
It would be desirable to be able to unload the engine manifold from exhaust system torque in a more reliable and efficient manner, and to do so at a more economical cost.
SUMMARY OF THE INVENTION
The invention comprises a flexible coupling which is capable, with respect to the transmission of torque forces, of decoupling the engine manifold and the exhaust pipe system in an automotive vehicle. The coupling comprises a flexible metal tube which has an inlet tube extending through one end and an outlet tube extending through the other end. The inlet and outlet tubes comprise portions of an exhaust gas flow path through the coupling and have interior ends located within the coupling. Means are provided for connecting the ends of the flexible metal tube to the inlet and outlet tubes. The interior ends of the inlet and outlet tubes are arranged so as to be capable of substantial angular movement relative to each other upon bending of the flexible metal tube. Thus, forces which tend to cause angular movement between the engine manifold and the exhaust system are taken up by the flexible coupling instead of being transmitted to the engine manifold.
The coupling may be insulated by insulating the exterior of the flexible metal tube and providing a second flexible metal tube to hold the insulation in place. The flexible tubes may be connected to the inlet and outlet tubes in the manner described in the more detailed description hereinafter so as to provide a gas-tight coupling which effectively prevents the escape of exhaust gas.
In a preferred arrangement, the inlet and outlet tubes have enlarged upstream portions, enabling the enlarged portion of the outlet tube to overlap either the downstream end of the inlet tube or the downstream end of an intermediate tube length of similar shape positioned within the inner flexible metal tube. This overlapping arrangement, while maintaining sufficient clearance between the inner flexible metal tube and the inlet and outlet tubes and any intermediate tube, permits the relative angular movement between the inlet and outlet tubes.
The above and other aspects of the invention, as well as other benefits, will readily be ascertained from the more detailed description of the preferred embodiments which follow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a portion of an automotive exhaust system incorporating the coupling of the present invention;
FIG. 2 is an enlarged side elevation of the portion of FIG. 1 enclosed within the circle 2;
FIG. 3 is an enlarged longitudinal sectional view of the coupling taken along line 3--3 of FIG. 2;
FIG. 4 is a transverse sectional view of the coupling taken along line 4--4 of FIG. 3;
FIG. 5 is a transverse sectional view of the coupling taken along line 5--5 of FIG. 3;
FIG. 6 is an enlarged transverse sectional view of the corrugated strip enclosed in the circle 6 in FIG. 3;
FIG. 7 is a longitudinal sectional view similar to that of FIG. 3, but showing the coupling in flexed condition;
FIG. 8 is a partial longitudinal sectional view similar to that of FIG. 3, but showing a modified arrangement;
FIG. 9 is a longitudinal sectional view similar to that of FIG. 8, but showing the coupling in flexed condition; and
FIG. 10 is a partial longitudinal sectional view similar to that of FIG. 8, but showing another modified arrangement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, the upstream portion of an automotive exhaust system 10 is schematically illustrated as comprising an engine 12 and an engine exhaust manifold 14 connected to exhaust pipe 16 by the coupling 18 of this invention.
As shown in FIG. 2, the coupling 18 comprises an outer flexible tube 20 connected to end caps 22 and 24. The upstream end cap 22 is connected to an inlet tube 26 while the downstream end cap 24 is connected to an outlet tube 28. The direction of flow of exhaust gases from the engine manifold is indicated by flow arrows 30. Although the inlet and outlet tubes may be connected to the exhaust system in any effective manner, for purposes of illustration the inlet tube 26 is shown as being connected to the engine manifold 14 by means of mounting flanges 32 and bolts 34, and the outlet tube 28 is shown as being connected to the exhaust pipe 16 by means of mounting flanges 36 and bolts 38. The coupling is shown in the flexed condition caused by torque forces generated during engine acceleration and deceleration. Referring to FIGS. 3 and 4, it can be seen that the inlet tube 26 comprises a downstream portion 40 of relatively small diameter and an upstream portion 42 of relatively large diameter. Similarly, the outlet tube 28 comprises a relatively small diameter downstream portion 44 of the same diameter as the inlet tube portion 40 and a relatively large diameter upstream portion 46 of the same diameter as the inlet tube portion 42. In practice, the inlet and outlet tubes preferably would be formed from lengths of exhaust pipe which have been enlarged at one end to form the shape illustrated. The enlarged portion may be formed by any suitable means, such as by swaging or by welding a larger diameter tube to a standard exhaust pipe section. However formed, the larger diameter portions should be upstream of the smaller diameter portions rather than in the reverse positions to prevent problems with back pressure and eddy currents in the exhaust gas flow.
The large diameter portion 46 of the outlet tube 28 overlaps the small diameter portion 40 of the inlet tube 26 over a substantial portion of their lengths. The inside diameter of the enlarged portion 46 is greater than the outside diameter of the smaller portion 40 by an amount which provides for an annular space 48 between the portions 40 and 46 for a reason to be explained later.
A flexible metal tube or hose 50 surrounds the inlet and outlet tubes 26 and 28 and is connected to them by suitable means to secure the flexible tube and the inlet and outlet tubes together as a unit. As illustrated in FIG. 3, a continuous weld 52 extending around the circumference of the inlet tube 26 connects the inlet tube to the upstream end of the flexible tube 50, while a continuous weld 54 extending around the circumference of the outlet tube 28 connects the outlet tube to the downstream end of the flexible tube. Because the flexible tube 50 should be radially spaced from the large diameter portion 46 of the outlet tube 28 situated between the extremities of the flexible tube, the welds 52 and 54 preferably engage the large diameter portions 42 and 46.
The outer flexible metal tube or hose 20 surrounds and is radially spaced from the first flexible tube 50 so as to provide an annular space for receiving a layer of insulation 58. The insulation may be of any type that will provide adequate insulating properties for the coupling, that is, being able to withstand exhaust gas temperatures in the range of 1600° F. to 1800° F. Although other insulating materials are capable of withstanding temperatures up to 1600° F., refractory fiber insulation is the most practical choice from the standpoint of resistance to temperatures exceeding 1600° F. and from the standpoints of insulating ability, cost and weight. Its low density of 4 pcf to 16 pcf permits it to be wrapped around the inner flexible metal tube without damage and to compress as necessary during transmission of torque.
The outer flexible tube 20 is attached to the cylindrical legs 60 and 62 of the end caps 22 and 24 by continuous welds 64 and 66, which provide a seal to the insulation 58. The shoulder portions 68 and 70 of the caps 22 and 24 are attached to the inlet and outlet tubes by spot welds 72 and 74. This arrangement is shown also in FIG. 5, which is an end view of the downstream end of the coupling and shows the spaced spot welds 74. It will be understood that the spot welds 72 at the upstream end would be similarly arranged. The use of spot welds at these locations instead of continuous welds limits heat transfer by conduction and also provides a path for the escape of water vapor which may have condensed within the confines of the spaced flexible tubes. By maintaining tight tolerances between the end caps and the inlet and outlet tubes, moisture in the form of road splash will be prevented from gaining access to the insulation.
The flexible tubes 50 and 20 may be of any suitable construction which permits flexing. Preferably, since the flexible tubes are formed of metal in order to resist the temperatures to which they are exposed and to provide adequate strength, they are of corrugated construction, as shown in FIG. 3. Corrugated tubes are typically formed by winding a continuous corrugated strip around a forming mandrel at an angle to the mandrel and attaching the edge of the strip to the edge of the strip in the next convolution. The edges of the strips are typically formed to initially loosely fit into or engage with each other, after which a forming roller compresses the edge configuration to clamp the edges together to form a continuous interlocking gas-tight seam. Thus, as shown in FIG. 6, the edges of the strip 76 are bent in upon themselves at 78 and 80 to form recesses or pockets in which similar shaped edges of adjacent strips fit. The resulting tube is able to bend or flex without destroying its gas-tight construction. Although flexible metal tubes of this same general configuration are readily available, it will be understood that other tube designs capable of providing a similar function may be employed if desired. When the coupling of FIG. 3 is subjected to stresses tending to flex or bend it, the flexible tubes 20 and 50 will flex accordingly as illustrated in FIG. 7. The arrangement of FIG. 3, whereby the large diameter portion 46 of the outlet tube is spaced from both the inner flexible tube 50 and the overlapped small diameter portion 40 of the inlet tube, allows the flexible tubes to bend even though the inner flexible tube 50 is connected to the rigid inlet and outlet tubes. Thus as shown in FIG. 7, enough space has been provided for the outlet tube 28 to become angled with respect to the inlet tube 26. Note that the lengths of the overlapping portions 40 and 46 are sufficient to provide a barrier to the flexible tubes against direct impingement of exhaust gases. Without this barrier the flexible tubes would not be able to withstand the hostile exhaust gas environment and would ultimately fail. During such flexing movement of the coupling, the insulation between the flexible tubes will be compressed to a degree at the inside radius of the bend and will be subjected to tension at the outside radius of the bend. The preferred insulation, being fibrous, is quite capable of accommodating this type of movement.
The arrangement of FIG. 3 is suitable for relatively short couplings which provide enough space for the overlapping inlet and outlet tubes to have sufficient relative angular movement. If, however, the flex requirements of the coupling are severe or the coupling cannot accommodate long overlapping lengths of tubing, the arrangement of FIG. 8 is preferred. In this modification the basic elements are the same and bear the same reference numerals as in FIG. 3, but an intermediate tube 82 has been added between the inlet and outlet tubes. The intermediate tube 82 is comprised of a relatively small diameter portion 84 and a relatively large diameter portion 86 of the same diameters as those of the inlet and outlet tubes. The large diameter portion 46 of the outlet tube overlaps the small diameter portion 84 of the intermediate tube, while the large diameter portion 86 of the intermediate tube overlaps the small diameter portion 40 of the inlet tube. By maintaining an annular space between the overlapping portions of the intermediate tube and the inlet and outlet tubes, and between the intermediate tube and the inner flexible tube in the same manner as in the first embodiment, and further by making the overlapping portions of the tubes sufficiently long, the inlet, outlet and intermediate tubes are able to angularly move relative to each other upon flexing of the coupling. This is further illustrated in FIG. 9, wherein the floating arrangement of the intermediate tube within the coupling which enables such angular movement is illustrated.
It is possible to lengthen the coupling or maximize the flexing even more by providing additional intermediate tubes. The arrangement of FIG. 10 illustrates such a modification wherein two intermediate tubes 88 and 90 are positioned between the inlet and outlet tubes 26 and 28. Both intermediate tubes have a floating arrangement whereby they are not connected to any of the elements in the coupling other than by being in overlapping engagement with each other and with the inlet and outlet tubes. The overlapped tubes will angularly move somewhat in the fashion of vertebrae to permit the flexible tubes to flex in response to stresses induced by engine torque.
It will be appreciated that there are no set dimensions that must be adhered to since the individual requirements of specific installations will cause them to vary. The diameters of the tubes and the clearance between overlapped portions must be sufficient, however, to permit the necessary flexure while maintaining the overlapped portions of a length sufficient to prevent direct impingement of exhaust gases on the inner flexible tube. The flexure requirements will vary between types of vehicles. The maximum flex angle requirement found to date has been in the order of 14°.
It is preferred that the inlet, outlet and intermediate tubes be formed from ordinary exhaust pipe tubing. By way of example, the small diameter portions of the tubes utilized in one embodiment were 2 inches in outside diameter and the large diameter portions were 2 1/16 inches in inside diameter, leaving a gap of 1/32 inch between the overlapped portions. In addition, the large diameter portions were spaced from the inner flexible tube by about 1/8 inch, and the length of the overlapped portions of the tubes was about 5/8 inch.
It will now be appreciated that the coupling of the invention provides an economical means of decoupling an automotive exhaust system from the engine manifold in terms of the transmission of stresses and vibration from engine torque. In addition, the decoupler of the invention also allows for expansion and compression of the exhaust system, thereby decoupling the engine on a three dimensional axis. Further, because of its unique design, the decoupler also isolates engine vibrations from the exhaust system, acting as a noise and vibration dampener.
The coupling is simple in construction, with the inlet and outlet tubes being held together by their connection to the inner flexible tube. The continuous weld employed for this connection makes the coupling gas-tight, preventing the escape of exhaust gases. The coupling also lends itself to being insulated by enabling the inner flexible tube to be surrounded with insulation.
It will be apparent that the invention is not necessarily limited to all the specific features described in connection with the preferred embodiments, but that changes to certain features which do not alter the overall function and concept of the invention may be made without departing from the spirit and scope of the invention, as defined in the appended claims. | A flexible coupling for connecting an engine manifold to an exhaust pipe to relieve torque. Concentrically spaced flexible tubes, which have insulation filling the annular space between them, are connected to inlet and outlet tubes having interior ends located between the ends of the flexible tubes. The inlet and outlet tubes have enlarged upstream ends and smaller downstream ends. By overlapping the ends of the inlet and outlet tubes, the tubes are able to have relative angular movement when the flexible tubes bend due to engine torque. One or more separate tubes which also have enlarged and smaller upstream and downstream ends may be provided to overlap with the inlet and outlet tubes to allow bending of longer couplings. | 5 |
CONTINUITY
This is a divisional of U.S. patent application Ser. No. 315,950, filed Sep. 30, 1994, now U.S. Pat. No. 5,628,546.
TECHNICAL FIELD
This invention relates to chairs for patients undergoing treatment, and more particularly, to dental patient' chairs.
BACKGROUND OF THE INVENTION
Dental patient's chairs come in a variety of types, styles, and sizes. Traditional dental patients' chairs are adjustable, typically by means of a simple pivot between the seat and the backrest which allows for simple articulation of the back as it rotates about the pivot. Such traditional chairs are, however, problematic for a number of reasons. First, it is typically important that the patient's head does not move relative to the headrest. Any time movement of a traditional dental chair is desired, the backrest pivots about an axis common to the seat. Upon pivoting the backrest, a person typically must move anywhere from a few to several inches in the chair in order to be seated squarely on the seat cushion with the backrest in the proper supporting position. Necessarily, the position of the patient's head relative to the headrest will change. This requires the treating physician to readjust the headrest.
Further, with respect to the patient's head, the patient's jaw and skull relative to the patient's backbone must be oriented in an optimal position for the dentist, oral surgeon or other treating physician to access the areas of the mouth. If the head and jaw move relative to the patient's backbone during adjustment of the chair, the patient may not be able to open his or her mouth sufficiently or there may be some other impediment to accessing the mouth areas.
A primary problem with respect to traditional dental patients' chairs is that the pivot axis, particularly a simple pivot between the backrest and the seat, is not coincident with the axis of the human body "pivot." Therefore, the person's body and the seat when articulating will not remain in constant, identical contact with one another. One attempt to solve this problem has been to try to locate the axis of the chair pivot close to the axis that is assumed to be where rotation of the upper torso takes place relative to the lower body. This, however, creates two problems. First, this would require a large hinge mechanism on the chair well above the seat cushion level that would get in the way of the patient getting in and out of the chair.
Perhaps more importantly, the human body does not pivot like a simple hinge. Rather, the human body has one hinge between the upper legs and the pelvic bone, and a second hinge between the lower part of the backbone and that same pelvic bone. This creates a complex hinge mechanism that must be dealt with in a sophisticated way.
An overriding consideration in today's medical profession, including the dental profession, is contamination. With the ever-increasing presence of serious diseases, such as AIDS, hepatitis, and the like, contamination has become particularly important. A major problem with respect to any dental patient's chair is the need for the treating physician to adjust the chair manually. For example, the physician is typically required to manipulate a variety of manually controlled switches or buttons, such as to adjust the headrest, backrest, or even the light used in treating the patient. Each time such an adjustment is required, the treating physician must put down the instruments, and readjust the particular piece of equipment. Any contamination on the treating physician's gloves will contaminate any of these various manually operated adjustments. These same adjustments are those that are typically not thought of when sterilization takes place between patients, as compared to the physician's instruments and the like.
Another important consideration is the patient's comfort and sense of security. The patient should not feel that he or she is sliding up and down in the seat in an uncontrolled manner, particularly where critical angles of inclination are involved. This occurs when a simple pivot, described above, is used in a patient's chair.
Some attempts have been made to place a sliding mechanism in the backrest portion of a chair to allow for the back to move when the seat is being reclined. Once again, however, this does not recognize the complex pivot that occurs in the human body. In addition, any mechanisms added to the backrest of the chair will create an impediment to the doctor performing work on the patient. In designing a dental patient's chair, the backrest should be kept as thin as possible so the doctor can have maximum patient positioning freedom while keeping his knees and legs free to get close to his patient.
There is a need, therefore, to provide a dental patient's chair that can be completely and fully manipulated without the need of the treating physician to touch any part of the chair with his or her hands. There is a further need to develop a dental patient's chair that pivots in the same complex manner as the human body so that when the chair is reclined, the human body will follow both the backrest and the seat in the exact same manner. This would eliminate any need for the patient to readjust him or herself in the chair, and would maintain the head in the relatively same position on the headrest.
The present invention relates to a dental patient's chair that is fully and completely adjustable by the use of a unique foot control system that eliminates the need to manipulate any hand-operated control knobs or levers. The present invention also involves a sophisticated linkage assembly which allows the seat to pivot and move in the same manner as the human body when the human body articulates about the complex pivot created at the pelvic bone, the upper legs, and the lower part of the backbone. This allows the patient's body to remain in the same position relative to the backrest and the seat of the patient's chair as the chair is articulated in a variety of positions. Other advantages, features, and objects of the invention will become more apparent from the detailed description of the invention that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are described below with reference to the accompanying drawings, which are briefly described below.
FIG. 1 is a side elevation view of a dental patient's chair according to the present invention;
FIG. 2 is a side elevation view of the dental patient's chair of FIG. 1 showing the various linkage mechanisms of the chair;
FIG. 3 is a side elevation view of the dental patient's chair of FIG. 1 with a portion of the linkage broken away to show a drive mechanism for adjusting the chair;
FIG. 4 is a side elevation view of the dental patient's chair of FIG. 1 in a lowered position;
FIG. 5 is a side elevation view of the dental patient's chair of FIG. 1 showing the chair in a fully inclined position;
FIG. 6 is an exploded view of the linkage assemblies of the present invention;
FIG. 7 is a side elevation view of the headrest assembly;
FIG. 8 is a side elevation view of the headrest assembly in an alternate position;
FIG. 9 is a top view of a foot control apparatus according to the present invention;
FIG. 10 is a side elevation view of the foot control apparatus of FIG. 9;
FIG. 11 is a partial bottom view of the foot control apparatus of FIG. 9;
FIG. 12 is a sectional, exploded view of some of the components of the foot control apparatus shown in FIG. 11;
FIG. 13 is a bottom view of the foot control apparatus of FIG. 9 without the base;
FIG. 14 is an exploded side elevation view of the components of the foot control apparatus of FIG. 13.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
This disclosure of the invention is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws "to promote the progress of science and useful arts" (Article 1, Section 8).
FIG. 1 shows a dental patient's chair 20 generally comprising a backrest assembly 22, a seat assembly 24, a footrest assembly 26, an armrest assembly 28, a linkage assembly 30, a lift mechanism 32, and a base or platform 34. The dental patient's chair is operated solely and exclusively by a programmable foot control apparatus 200 which can be positioned anywhere on the ground at the rear end of the dental patient's chair. Ideally, it will be positioned for convenient operation by the treating physician. The foot control apparatus emits an infrared signal which is transmitted to and received by a PC board 160 mounted inside of the dental patient's chair. The chair shown in FIG. 1 includes a breakaway portion to show where the PC board 160 may be located.
FIGS. 2 through 6 show more specifically the various features of the dental patient's chair. The seat assembly 24 includes a seat frame 36 which is moved through a variety of horizontal and vertical positions as the chair articulates because of the main linkage assembly 30. The frame comprises side members 36 which are attached to one another by a cross bar 37. (FIG. 6 shows left and right components of the chair that are mirror images of one another by adding an "a" or a "b" designation to the component number). A pair of arm posts 38 are rigidly coupled to the frame 36. A pair of armrests 39 are coupled, in turn, to the arm posts 38.
The seat frame 36 moves generally relative to the main or reference frame 40. The reference frame comprises side members 40, which are secured together by a cross brace 41 and a tubular cross member 47. The seat frame 36 is attached to the reference frame 40 solely by means of a butterfly linkage member 42 and a boomerang-shaped linkage member 44. The main frame further comprises upstanding arms 46 which are fixedly coupled to the ends of tubular cross member 47. The top ends of arms 46 pivotally couple the backrest assembly thereto at triangular shaped brackets 50. A pair of push bars 48 are coupled at one end to the triangular pieces 50 and pivotally coupled at opposite ends to the butterfly linkage members 42. When the chair is articulated, the push bars 48 urge the lower portion of the butterfly bars 42 toward the front of the chair, which causes the top portion of the butterfly linkage members 42 to move the seat in a rearward position. The boomerang linkage member 44 moves the seat in an upward position as the seat frame 36 moves relative to the reference frame 40. The butterfly and boomerange members are different lengths and pivotally mounted in the manner shown so that the seat tilts when the it moves between the forward/rearward and upward/downward directions.
The backrest assembly 22 is coupled to the seat frame assembly 24 by means of a pair of triangular-shaped brackets 50 which are interconnected to one another by means of a cross bar (unnumbered), as shown in FIG. 6. A banana-shaped bracket 51 is fixedly coupled to the cross bar and the triangular-shaped mounting brackets 50. A pair of support stays 53 are cantilevered from the banana bracket 51 and provide a support basis for the backrest cushion 52 (FIG. 2). An adjustable headrest assembly 56 is inserted in between the stays 53 and secured in a relative position by means of a coupling member 54 which includes a ratchet mechanism 55. The headrest assembly includes a tongue portion 58 which is inserted through the coupling member 54, as the tongue member is inserted between the stays 53.
The footrest assembly 26 is pivotally coupled to the seat frame 36 by means of a pair of cam links 60. The footrest assembly 26 comprises a pair of parallel mainframe members 64 attached to one another by a cross member 65.
A pair of bearing wheels 66 are rotatably attached to the reference frame 40 for engaging the cam surface 62 of the cam links 60. Each of the cam links 60 includes a cam surface 62 for engaging the bearing wheels 66. As the seat frame 36 moves relative to the reference frame 40, the cam surface 62 engages the bearing wheel, which will change the orientation of the footrest assembly 26.
The reference frame 40 is vertically supported by means of a height adjustment assembly 32 which comprises essentially a parallelogram linkage. This height adjustment assembly specifically comprises a main vertical support member 68 and a pair of parallelogram support arms 70. The main vertical support member 68 and the parallelogram arms are pivotally coupled, on one end, to upstanding mounting brackets 72 on one end, and to a lower portion of the reference frame 40 on opposite ends. A vertical drive means in the form of a screw jack assembly 74 is used to move the chair vertically. The screw jack assembly 74 comprises a motor or drive means 76 which rotates a threaded extension portion 78. The motor is mounted to the base by means of a motor bracket 80 which is pivotally coupled to a base plate mount 82. A threaded coupling 86 is pivotally mounted, in turn, to a pair of flanges 84 which extend down from the main vertical support member 68. As the screw jack assembly rotates the threaded portion 78, the threaded coupling 86 is drawn toward the motor 76, which causes the parallelogram linkage to lower the dental patient's chair in a vertical position.
The inclining and reclining of the seat chair is actuated by a seat drive means in the form of a second screw jack assembly, which comprises a motor 92 which rotates a screw or threaded extension portion 94. The motor 92 is pivotally secured by means of a motor mounting bracket 96 to a mounting member 98 attached to the cross bar of the backrest assembly 22. The threaded extension portion 94 is threadably inserted into a threaded coupling 100 which is secured, in turn, to a coupling mount attached to the cross bar 37 of the seat frame 36. When it is desired to move the chair into an inclined position, the screw jack assembly 90 rotates the threaded portion 90 which draws the coupling 100 toward the motor 92. This causes the butterfly linkage member 42 and the boomerang-shaped linkage member 44 to rotate (counterclockwise as shown in FIG. 2). This causes the seat frame 36 to move simultaneously in backward and upward directions relative to the reference frame 40 in a manner which replicates the movement of the human body upon articulation. The specific degree and amount of vertical and horizontal movement of the seat frame 36 depends upon the lengths of the butterfly and boomerang linkage members. These have been determined by computer-simulation of the exact articulation of the human body.
With reference to FIG. 4, the various pivot points are disclosed. The lower parallelogram linkage, which allows for the vertical movement of the chair, is defined by pivot points 110, 112, 114 and 116. The boomerang-shaped member 44 is pivotally mounted to the reference frame at pivot point 118, and pivotally mounted to the seat frame at pivot point 120. The butterfly linkage member 42 is pivotally coupled to the reference frame 40 at pivot point 126 . The butterfly member is further pivotally coupled on one end to the push bar 48 at pivot point 122 and at an opposite end at pivot point 124 on the seat frame. The backrest assembly rotates about pivot point (on triangular shaped piece 50 just above point 130 in FIG. 4) when the backrest is rotated relative to the seat frame assembly.
FIG. 7 shows one possible position of the headrest assembly 56. The headrest assembly includes a headrest cushion 140 which is pivotally secured to a dual pivot member 42 at pivot point 144. The dual pivot member 142 is coupled, in turn, to the tongue member 58 of the headrest assembly at pivot point 46. In the position shown in FIG. 7, the headrest assembly is at an extended position for a tall person.
FIG. 8 shows an alternative position of the headrest assembly 56 with the headrest cushion 140 being articulated at pivot point 144 to allow the tongue 58 to be inserted into the seat cushion area 52 and to allow the dual pivot member 142 to be articulated down. In the position shown in FIG. 8, the headrest assembly 56 can be adjusted to suit a small person or child.
FIG. 9 shows a foot control apparatus according to the present invention. The foot control apparatus includes an outer shell 202 and a plurality of apertures 204, 206, 208, which allow infrared beams to be transmitted to receiving devices in the dental patient's chair. The foot control apparatus includes four main areas, A, B, C, and D, on the top surface of the shell 202. By manipulating the foot control apparatus (discussed below), the dental patient's chair is fully and completely adjustable without the need for the treating physician to adjust any hand-operated control mechanisms.
FIG. 11 shows a bottom view of a portion of the foot control assembly. A trapezoid-shaped piece 210 is mounted to the underside of the shell 202. The trapezoid piece provides an lower horizontal surface (since the foot control has a curved outer surface) which enables an even vertical force to be placed upon the other members of the foot control apparatus. A pair of spring steel members 212, 214 are mounted in a crosswise fashion to the underside of the trapezoid-shaped piece 210 by means of a fastener 216. The extreme ends of the spring steel members 212, 214 provide the means for creating the actuating force or forces to operate the foot control apparatus. A resilient spacer 218 is positioned under the trapezoid-shaped piece 210 to allows the cover to tilt in its mounted position.
As shown in FIGS. 13 and 14, the footrest assembly further comprises a circuit board 224 which is attached to the base 230 of the foot control apparatus through a spacer 222. A plurality of switches (not shown) are coupled to the circuit board. A plurality of fasteners 226 are inserted through the circuit board 224 through the spacer 220 and threadedly received by the base 230. A battery (not shown), which provides power to the circuit board and the infrared emitter (not shown), is held by a retaining clip 228 mounted to the base 230. A removable cover 231 is secured to the exposed, bottom side of the base 230 by means of a fastener 232. The cover 230 can be removed to provide access to the battery storage area. A plurality of rubber feet 234 are further attached to the bottom surface of the base 230.
When pressure is applied to any location of the outer edge of the cover, the cover will tilt and contact one or more switches mounted on the circuit board. That is, the spring arms will actuate one or more of the switches. This will case the microcomputer in the foot control to send a signal, preferably an infra red signal or signals, to the receiver on the patient's chair. These switches may be timer switches so that a tap or series of taps on a location of the edge of the cover will cause a particular signal to be sent from the foot control to the receiver on the patient's chair. The foregoing are but examples of the various signals that may be generated by the foot control and the various ways for actuating switches on the circuit board inside the foot control assembly.
In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents. | A dental patient's chair which is fully and completely adjustable which includes a foot control system that eliminates the need to manipulate any hand-operated control knobs or levers. The dental patient's chair includes a linkage assembly which allows the seat to pivot and move in the same manner as the human body when the human body articulates about the complex pivot created at the pelvic bone, the upper legs, and the lower part of the backbone. The dental patient's chair allows the patient's body to remain in the same position relative to the backrest and the seat of the patient's chair as the chair is articulated in a variety of positions. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The innovation relates to a floor strip for bridging a join between two floor coverings that border on one another.
[0003] 2. The Prior Art
[0004] A floor profile arrangement is shown in German Patent No. DE 201 17 167 U1, in which a base profile having two upright shanks accommodates a cover profile that engages over the two upright shanks with two crosspieces, so as to be adjustable in height. In order to bridge greater heights, the crosspieces are configured to be somewhat longer on the underside of the cover profile. In order to equalize excess lengths when pushing the floor profile and the cover profile together, depressions or perforations are provided in the side arms of the floor profile, which accommodate the excess lengths. Pivoting of the cover profile in the case of floor coverings having different thickness is not possible.
[0005] Another floor profile arrangement is shown in German Patent No. DE 203 20 273 U1, in which an articulation is provided on a base profile. An upright connecting part having a drive channel is held in the articulation in an articulated manner. A cover profile engages over the connecting part with two crosspieces molded onto its underside. The crosspieces form the guide, and the cover profile is fixed in place in the drive channel with screws that engage from above. In order to be able to pivot the cover profile even when the crosspieces have been pushed far over the floor profile, lateral recesses have been provided in the floor shank(s) of the floor profile, and, at the same time, the crosspieces have been shortened at the other locations, so that they offer the side guide only in partial regions. The crosspieces that are dually set onto the cover profile require broad joins between the adjacent floor coverings, particularly if two coverings having different thickness border on one another, and the cover profile has to be greatly inclined. Because of the low point of rotation and the crosspieces that stand far apart from one another, the cover profile is greatly displaced laterally when it is pivoted, and in many instances, the floor covering is not grasped sufficiently, so that the base profile has to be loosened and re-attached to the floor after it has been moved.
SUMMARY OF THE INVENTION
[0006] It is therefore an object of the invention to equalize great height differences in floor coverings having a different thickness, with a cover profile held in an articulated manner relative to the base profile, without any bump, and to hold the coverings together as tightly as possible.
[0007] This object is accomplished by a floor strip for bridging a join between two floor coverings that border on one another, comprising a base profile that can be fixed in place on the floor, two upwardly extending shanks molded on the base profile, and a cover profile having at least one cover wing that projects laterally. There is a downwardly directed crosspiece, which is connected with the base profile by way of an articulation. The articulation is formed by an articulation rail that is rounded on both sides and grasped between the shanks of the base profile. The shanks are upright but rounded on the inside. The articulation rail is formed by a solid material or by a sleeve, which has a longitudinal groove, into which the crosspiece and/or an attachment means that engages through the cover profile passes. In certain sections, the longitudinal groove passes completely through the articulation rail to form perforations, and the crosspiece of the cover profile has a greater depth in these regions.
[0008] Via the groove in the articulation rail, which passes all the way through, the crosspiece of the cover profile can be introduced further, specifically directly through the center of the articulation. As a result, the cover profile comes to rest lower on the floor covering, because the crosspiece does not get stuck in the articulation rail, but rather passes through all the way to the floor profile. During pivoting, the crosspiece that passes through the center of the articulation rail has the advantage that the join region between the adjacent coverings can be made narrow. Because of passing centrally through the articulation rail, the cover profile is hardly displaced laterally at all during pivoting, so that the floor coverings are sufficiently grasped in every slanted position, and the join is covered.
[0009] Even greater equalization of the height difference can be achieved if the base profile is provided with recesses that pass through it, under the section-wise perforations of the articulation rail. The depth region for inserting the crosspiece of the cover profile is increased even further with the recesses in the base profile below the continuous groove through the articulation rail. If one was previously able to utilize ¾ of the region of the diameter of the articulation rail as a holding or guiding part for the crosspiece to be inserted, and therefore several cover profiles having crosspieces of different lengths were required for floor coverings having different thickness, it has now become possible to equalize significantly greater difference ranges with one crosspiece length, and in particular, to do so by passing right through the center of the articulation all the way to the floor on which the base profile is fixed in place. The crosspiece cannot be inserted any deeper than that, unless one were to chisel out the floor underneath at these locations.
[0010] In order to sufficiently pivot the cover profile in any desired position, so that the floor covering is sufficiently grasped, even if the floor coverings have only a low height and the crosspiece must penetrate deep through the groove, it is advantageous to configure the recesses in the base profile to be so wide that the crosspiece of the cover profile that engages through the articulation rail has a pivoting freedom of 20°. It has been shown that pivoting freedom of 10° toward each side is sufficient for grasping the coverings. Since the articulation rail with its groove is situated directly above the recess of the base profile, the cutout for a pivot of 20° is only slight, so that the base profile is not weakened by this recess. As experiments have shown, it is possible to place even larger cutouts, because they are always provided only in certain sections. Sufficient rigidity remains for the base rail, even if it consists of plastic and not of metal, because it is fixed in place on the floor by means of being glued or screwed down.
[0011] In order to equalize the greatest possible height difference with the cover rail, it is practical to make its crosspiece quite long. The correct length for the crosspiece is obtained when the crosspiece of the cover profile has a depth directed downward, in the section region of the recesses that pass through, that reaches all the way to the floor in the lowermost position of the cover profile, so that it sits on the upwardly standing shanks of the base profile. This length can easily be measured, and it guarantees that the crosspiece touches the direct floor in its lowest position, and is not held back by the base profile.
[0012] Because the recesses in the articulation rail and the base profile are provided only in certain sections, and therefore have specific lengths, the extended crosspieces must be adapted to these lengths. For safety reasons, it is advantageous if the extended crosspiece of the cover profile that engages through the recess is configured to be shorter in the longitudinal rail direction than each of the lengths of the perforations and recesses provided in certain sections, through the articulation rail and the base profile. The cover profile may shift slightly, in the longitudinal direction, relative to the base profile and/or the articulation rail. Even then, the crosspiece should be able to engage through the recesses, in order to lock the cover profile in place quite low above the floor and grasp the covering.
[0013] In order for the cover profile to find sufficient hold in the articulation rail despite its shifting seat, the crosspiece of the cover profile engages through the groove passing through the articulation rail with a slide fit. The cover profile can be pulled out of the articulation rail relatively far, because of the greater depths of the crosspieces, and the crosspiece ends still have sufficient hold in the slide rail because of the seat for slide fit, and do not bend or actually fold over. The crosspieces with the greater depths are only provided in certain sections.
[0014] It is advantageous if the articulation rail, when it is configured as a sleeve, has edge ends directed upward on its upper longitudinal groove. An acute-angle toothed rib directed inward, in each instance, is molded on these edge ends as an end piece. The beaded edge on the groove of the sleeve-like articulation rail possesses an extension for holding the crosspiece of the cover profile, because in this way, additional side walls are created, which can rest against the crosspiece on both sides. The toothed rib that is molded on as an end piece holds the inserted crosspiece tightly in place even if it engages between the edge ends only with a slight length. The toothed ribs engage the crosspiece with a firm hold from both sides, at the required height. This can be from the outer end to below the laterally projecting cover wings of the cover profile. Therefore great height equalization is possible with one part.
[0015] In order for the seat and the hold of the cover profile to be even better and firmer if the crosspiece is pushed somewhat further into the articulation rail, the articulation rail has an additional toothed rib directed at an inward and downward slant inward on the edge ends, which stand upright, below the end piece. With the second toothed rib that is directed at a slant inward and downward, the crosspiece is grasped twice and therefore has no possibility of coming loose.
[0016] It is advantageous if the slanted outer edge ends of the longitudinal groove of the articulation rail serve as a stop at the ends of the shanks of the base profile. The cover profile orients itself, in terms of its slanted position, essentially by supporting its wing edges on the floor covering. As long as the edges have not yet reached the floor covering, it is advantageous if the cover profile does not angle off too greatly, in order to remain in the pivot range when it is set down. Practice has also shown that pivoting of 20° is sufficient for adaptation to the floor coverings having different thickness.
[0017] In order for the cover profile to be able to hold itself in the articulation rail with its crosspiece, the crosspiece of the cover profile and the insides of the longitudinal groove in the solid material of the articulation rail are equipped with a surface structure that engage into one another. The surface structure can be a fine graining with which a hold is possible with almost step-free displacement. However, reciprocal furrowing or tooth-provision is also possible, in order to achieve an advantageous hold for the cover profile, which can also be adjusted if it has become loose over time and fixation in place only occurs by way of the surface structure. Since the sleeve-like articulation rail is already equipped with toothed ribs, these have a firm grip on the crosspiece of the cover profile if the crosspiece has a marked surface structure.
[0018] Finally, the firm seat for the cover profile is increased in every height position if the surface structure extends on both sides over the entire surface of the crosspiece. An attempt is made, with the innovation, to cover a greater height difference of floor coverings, without using additional parts or actually replacement parts. Consequently, it is advantageous if the crosspiece of the cover profile is as long as possible, thereby can be pulled far out of the groove of the articulation rail, and nevertheless finds sufficient hold in the articulation rail that it also holds the floor covering. On the other hand, it should be possible to push the crosspiece quite deeply through the articulation rail, all the way to the floor, in order to grasp coverings having a thin wall, and to still find sufficient hold in the articulation rail groove even then. This can be achieved if the surface structure extends on both sides over the entire surface of the crosspiece.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.
[0020] In the drawings, wherein similar reference characters denote similar elements throughout the several views:
[0021] FIG. 1 shows a floor strip that can pivot, pulled apart;
[0022] FIG. 2 shows another floor strip, joined together;
[0023] FIG. 3 shows the floor strip, joined together, in a low arrangement;
[0024] FIG. 4 shows an articulation rail in sleeve form;
[0025] FIG. 5 shows a floor strip cut open from the side, broken down in an exploded view;
[0026] FIG. 6 shows another floor strip, and
[0027] FIG. 7 shows the previous floor strip, pulled apart in an exploded view and cut open from the side.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0028] As can be seen in FIG. 1 , floor strip 1 consists of a base profile 2 , which has a lateral flange 3 , with which it is fixed in place on the floor. Furthermore, two shanks 4 that are molded on and are directed upward proceed from base profile 2 , which shanks are rounded on the inside and serve as articulation bearings 5 . In articulation bearing 5 , an articulation rail 7 is held by rounded inside surfaces 6 of shanks 4 , so as to rotate. Articulation rail 7 is laterally adapted to the rounded regions of inside surface 6 of shanks 4 , and has a groove 8 that is open toward the top, into which a crosspiece 9 of a cover profile 10 engages, which is molded onto the underside of cover profile 10 . Cover profile 10 has two lateral wings 11 , one of which could be angled away if cover profile 10 is used as an edge delimitation. With the two edges 12 , cover profile 10 grasps the floor coverings, not shown, which form a join at the abutment point, which join is bridged by cover profile 10 . Crosspiece 9 engages into the groove 8 of articulation rail 7 , in order to hold itself or at least to give cover profile 10 a good guide in the vertical direction, when the profile is pressed onto the floor covering.
[0029] In order to make it possible for cover profile 10 to be pressed more deeply onto base profile 2 , and for crosspiece 9 not to sit on the bottom of groove 8 in articulation rail 7 , articulation rail 7 is configured so that groove 8 passes completely through it, in certain sections. The sections that are completely open or cut out are indicated with 13 . Crosspiece 9 has extended depths 14 at these perforations 13 , which are present in certain sections, which depths are configured to be slightly shorter than section-wise perforations 13 , in the longitudinal direction of floor strip 1 . In this way, it is guaranteed that extended depths 14 will pass through perforations 13 even if they are slightly displaced in the longitudinal direction. Because of the greater depth 14 , crosspieces 9 can be drawn further out of groove 8 and hold thicker floor coverings. Crosspieces 9 nevertheless still find sufficient hold in groove 8 .
[0030] In order to be able to equalize an even greater height difference, an even greater depth 14 was given to crosspiece 9 in certain sections. For this purpose, base profile 2 was also provided with corresponding cutouts 16 , on bottom flange 15 , below articulation rail 7 , specifically directly below section-wise perforations 13 . These cutouts 16 in base profile 2 can be seen in FIG. 2 .
[0031] In FIG. 2 , the crosspiece 9 of cover profile 10 is inserted in the uppermost position, and is held by the last elevation of furrows 17 of groove 8 . Since groove 8 of articulation rail 7 is configured as a drive channel having a furrowed or ribbed surface structure 18 , a screw, not shown, that passes through cover profile 10 could be provided in addition to crosspiece 9 . Crosspiece 9 would have a recess at this point, so that the screw finds sufficient grip in the drive channel. It is important that crosspiece 9 engages centrally through the articulation rail 7 and articulation bearing 5 , and furthermore through base profile 2 , in order to make the deepest possible depth with crosspiece 9 , and remain in the tightest space.
[0032] In FIG. 3 , the same floor strip 1 as in FIG. 2 can be seen, but here cover profile 10 is completely pressed down, so that crosspiece 9 , with its extended length 14 , engages entirely through articulation rail 7 and through cutout 16 of base profile 2 , all the way to floor 19 . In this position, cover profile 10 sits on top of shanks 4 of base profile 2 , which project upward, or on top of top groove edges 20 of articulation rail 7 , if these project out of articulation bearing 5 . Crosspiece 9 is configured to be so wide that it sits in the groove with a slide fit, with its smooth wall, and can be displaced without resistance. With this configuration, cover profile 10 gets its hold in groove 8 , i.e. in the drive channel, from a screw that passes through. Cutout 16 is cut out so wide, in base profile 2 , that crosspiece 9 , which passes through articulation rail 7 , can pivot freely by at least 20° with its extended depth 14 , and thereby brings cover profile 10 into the desired slanted position so that it is set down on the floor coverings on both sides with edges 12 of wings 11 , and is able to hold them. Cover profile 10 is reinforced with a reinforcement rib 29 on each wing 11 , on its underside. This reinforcement rib 29 offers cover profile 10 greater rigidity, even if the wall thickness of wing 11 is only 1.5 mm.
[0033] In FIG. 4 , floor strip 1 is pulled apart, in an exploded view, and additionally cut longitudinally. As a result, it is very easy to see recesses 16 in base profile 2 , which are cut out of floor flange 15 in certain sections. Furthermore, one can see the rounded inside surface 6 of articulation bearing 5 , which is part of the one shank 4 , in which articulation rail 7 , shown above it, is mounted. Groove 8 provided in articulation rail 7 has a surface structure 18 of furrows that run longitudinally, in connection with which crosspiece 9 of cover profile 10 slides by when it is inserted into the groove 8 . Above recesses 16 of base profile 2 , passage perforations 13 of groove 8 are provided in articulation rail 7 , through which extended depths 14 engage, which are also provided in certain sections, like perforations 13 and recesses 16 . As can be seen, extended depths 14 extend over a shorter section in the longitudinal direction than perforations 13 and recesses 16 that are provided in certain sections, which are essentially disposed one on top of the other. Extended depths 14 are provided to be so long and at sufficient intervals that in the case of the uppermost position according to FIG. 2 , cover profile 10 , with its crosspiece 9 , i.e. its depth 14 , still finds sufficient hold in the groove 8 of articulation rail 7 .
[0034] As is evident from FIG. 5 , crosspiece 9 and its extended depth 14 of cover profile 10 are completely covered with a tooth pattern in the longitudinal direction as surface structure 18 . Articulation rail 7 is also configured accordingly; this will be discussed in greater detail in connection with the next figure. In FIG. 5 shows depths 14 that have been molded onto crosspiece 9 in certain sections, and perforations 13 and cutout or recesses 16 that are provided in certain sections of articulation rail 7 disposed below, and base profile 2 , shown again below that. Perforations 13 and recesses 16 are provided so that crosspieces 9 can engage completely through the articulation, all the way to floor 19 , with their depths 14 , in order to thereby lose height if crosspiece 9 nevertheless has a great depth. Depths 14 have a shorter length 20 , in the longitudinal direction of the strip, than perforations 13 with their length 21 in articulation rail 7 , and recesses 16 with their length 22 in the base profile 2 , whereby lengths 21 and 22 are the same.
[0035] In FIG. 6 , articulation rail 7 is shown as a sleeve, which is preferably produced from plastic having a Shore hardness of approximately 80 to 90. This sleeve shape has the required rounded surfaces 23 on the side, with which it is held in the articulation bearing 5 , by inside surfaces 6 of base profile shanks 4 , so as to rotate. Toward the top, sleeve-like articulation rail 7 is provided with a slot or a groove 8 for accommodating crosspiece 9 of cover profile 10 , edge ends 24 of which are drawn upward. Edge ends 24 have a toothed rib 25 , directed into groove 8 as the end piece, which assures sufficient fixation of crosspiece 9 . In order to further increase the attachment of crosspiece 9 in articulation rail 7 , another toothed rib 26 , directed inward, is molded on below toothed rib 25 , at a slight distance, like a saw tooth. Lower base 27 of sleeve-like articulation rail 7 is provided with perforations 13 , in certain sections, so that depths 14 of crosspiece 9 can pass through without resistance when penetrating deeper, and cover profile 10 loses height.
[0036] In FIG. 7 , the assembly of a floor strip 1 having a sleeve-like articulation rail 7 can be seen. Base profile 2 is attached to the floor with its side flange 3 . Sleeve-like articulation rail 7 is mounted between upright shanks 4 of base profile 2 , so as to rotate, and the rail is held in inside surfaces 6 of articulation bearing 5 with its rounded side surfaces. In base profile 2 , section-wise cutout 16 in the floor flange 15 is configured to be wider for the pivot range of crosspiece 9 . Above cutout 16 , perforation 13 for passage of crosspiece 9 or its extended depth 14 is provided in sleeve-like articulation rail 7 . Cover profile 10 , with its crosspiece 9 formed on the underside, and with depth 14 that is extended in certain sections, is inserted into groove 8 of articulation rail 7 . Toothed rib 25 molded onto high-drawn edge end 24 engages into ribbed surface structure 18 of depth 14 , and already provides a firm hold. In this position, the greatest hold of cover profile 10 is assured. Cover profile 10 can be pressed down completely, until it sits on the floor coverings, not shown, with its edges 12 of cover wings 11 . With floor coverings having different heights, cover profile 10 will pivot with articulation rail 7 , until both edges 12 have contact with the floor covering. If the floor covering is very low, crosspiece 9 will penetrate very far into groove 8 of articulation rail 7 , and in the bottommost position, depths 14 pass through perforations 13 and cutouts 16 all the way to floor 19 , whereby then, the wings come to lie on the upper end 28 of shanks 4 . When edge ends 24 of articulation rail groove 8 look out of upright shanks 4 of the base profile, cover profile 10 , in its lowermost position, already sits on these edge ends 24 , and section-wise depths 14 touch floor 19 . In the angled position, the outermost edge end 24 of the longitudinal groove 8 of the articulation rail 7 lays itself against the upper end 18 of the shank 4 of the base profile 2 , and utilizes it as a stop.
[0037] The innovation is not restricted to the exemplary embodiments disclosed above. Instead, a plurality of variants, modifications, and combinations of individual details described in different embodiments is possible, which also make use of the idea of the invention, and therefore fall within the scope of protection.
LIST OF REFERENCE NUMERALS
[0038]
[0000]
1
floor strip
2
base profile
3
side flange
4
shank
5
articulation bearing
6
inside surfaces
7
articulation rail
8
groove
9
crosspiece
10
cover profile
11
wing
12
edge
13
perforation
14
extended depth
15
floor flange
16
cutout, recess
17
furrows
18
surface structure
19
floor
20
length of the depth 14
21
length of the perforation 13
22
length of the recess 16
23
rounded surface
24
edge ends of the groove
25
toothed rib
26
toothed rib (saw tooth)
27
lower base of the articulation rail
28
shank end
29
reinforcement rib | A floor strip for bridging a join between two floor coverings that border on one another comprises a base profile that can be fixed in place on the floor, two upwardly extending shanks molded on the base profile, and a cover profile having at least one cover wing that projects laterally. There is a downwardly directed crosspiece, which is connected with the base profile by way of an articulation. The articulation is formed by an articulation rail that is rounded on both sides and grasped between the shanks of the base profile. The shanks are upright but rounded on the inside. The articulation rail is formed by a solid material or by a sleeve, which has a longitudinal groove, into which the crosspiece and/or an attachment means that engages through the cover profile passes. In certain sections, the longitudinal groove passes completely through the articulation rail, and the crosspiece of the cover profile has a greater depth in these regions. | 4 |
BACKGROUND OF THE INVENTION
[0001] Field of the Invention: This invention relates to the field of general purpose computer systems and to the efficient and coherent processing of DMA transactions between I/O devices and shared memory.
BACKGROUND OF THE INVENTION
[0002] General purpose computer systems are designed to support one or more central processors (CPUs) on a common CPU bus, one or more external I/O devices on one or more standard I/O buses, a shared system memory, and a system controller that serves as a communications interface between the CPU bus, the I/O bus, and the shared system memory. All of the CPUs and at least one, but typically most, of the I/O devices can communicate with the shared system memory. Cache memory has been incorporated into the CPUs of such computer systems in order to minimize the number of bus cycles or bandwidth needed to service transactions between the CPUs and the shared memory. This CPU cache architecture frees up bandwidth for other devices, such as I/O, to access the shared memory thereby speeding up the overall computer system operation.
[0003] With multiple system devices able to write to and read from the shared memory it is necessary to prevent inconsistencies in the value of data between a version in CPU cache and a version in shared memory. This is accomplished by implementing a data value consistency protocol in the computer system. This protocol is referred to as a cache coherency protocol and it typically is incorporated into the functionality of each processor in the form of a cache controller. A common protocol used to maintain coherency is called snooping.
[0004] The external I/O devices mentioned above can be, for example, disk drives, graphical devices, network interface devices, multimedia devices, or I/O processors and they are typically designed to interface to standard bus protocols, such as the PCI bus protocol. Alternatively, the I/O bus and external I/O devices could be replaced by another CPU bus and CPU units, so the Computer System would have two CPU subsystems. I will refer to the external I/O devices simply as I/O devices. In order to more rapidly move information between these I/O devices and the shared system memory, computer designers invented a mechanism for off-loading this rapid information movement from the CPU. This mechanism is called Direct Memory Access (DMA).
[0005] In order to maintain CPU cache coherency, it is necessary to ensure that all DMA read and write transactions between I/O devices and shared memory adhere to coherency rules. However, standard I/O devices may provide only partial support for cache coherency functionality. In this case, the system controller can incorporate functionality that operates to enforce cache coherency. Regardless, a cache coherency protocol is run by every CPU in the system that supports on-chip cache. As the cache memory and associated coherency functionality are tightly integrated into the design of each CPU device, the CPU is much better positioned in the computer system to perform this cache coherency protocol efficiently.
[0006] Some system controllers are designed to be used in multiple different standard modes of operation; two of which are a coherent mode and a non-coherent mode. The non-coherent mode is well suited to very rapidly move large amounts of data between I/O and shared memory while the coherent mode is better suited for processing housekeeping type transactions which are typically small transactions dealing with the properties of data as opposed to the data itself. For example, these types of transactions would contain status information such as packet received or sent, checksum information, or information about the next DMA transaction. These housekeeping types of transactions might not be directly controlled or generated by an application program.
[0007] More specifically, when a system controller is operating in the non-coherent mode of operation, it transmits DMA requests from I/O directly to the shared memory. Although this is the highest bandwidth communications path between I/O and the shared memory, such non-coherent transactions may result in the creation of inconsistencies in the various versions of data stored at different locations in the computer system.
[0008] On the other hand, when a system controller is operating in the coherent mode, it receives DMA requests from the I/O and buffers them, and then utilizes its own coherency functionality to communicate with the cache at each CPU. This communication could be a message to flush cached data before a read request or invalidate cached data before a write request. As a system controller's coherency functionality does not operate nearly as efficiently as the CPUs coherency functionality, processing DMA requests in the coherency mode takes much more time than processing the same DMA request in the non-coherent mode. Therefore, it is not desirable to utilize the coherent mode of system controller operation to process DMA requests.
[0009] In order to successfully complete I/O transactions in the non-coherent mode, it is necessary for the I/O device drivers to enforce coherency. Unfortunately, standards-based I/O device drivers do not usually arrive from the manufacturer ready to support cache coherency for I/O-processor bus transactions that operate in a non-coherent manner, so typically it is necessary for the customer to modify the I/O device driver to enable such non-coherent operation. Such modification of the I/O device driver can be time consuming and costly and defeats the purpose of using general purpose, standards based I/O units.
[0010] One method for enforcing cache coherency during DMA transactions between I/O and shared memory is to inhibit the CPU cache from storing portions of shared memory that were accessible to the I/O units. In other words, the CPU cache would be effectively turned off and the CPU would be forced to access shared memory, as needed, on a word-by-word basis. This would serve to unnecessarily slow the operation of the processor and hence the entire system.
[0011] As mentioned above, another solution to the cache coherency problem is to incorporate cache coherency functionality into the system controller. Essentially, the system controller buffers all I/O requests until the transactions can be processed such that the value of all versions of the data are maintained in a coherent fashion. This process can involve the flushing or invalidating of cache as mentioned previously.
[0012] Although providing cache coherency at the system controller has resulted in the rapid processing of DMA transactions between I/O and shared memory, and although this cache coherency functionality does rapidly complete DMA transactions that involve merely housekeeping transactions, the system controller coherency functionality continues to be a significant bottle-neck for DMA transactions that involve the movement of large amounts of data from shared memory directly to I/O units (data reads) and to lesser extent slows DMA transactions involving large amounts of data from I/O units to shared memory (data writes).
SUMMARY OF THE INVENTION
[0013] I have discovered that it is possible to significantly increase the data rate of DMA transactions between I/O devices and shared memory, without the need to modify the I/O device drivers, by disabling the system controller coherency protocol and programming the system controller to transmit the I/O request directly to the CPU bus. Further, I have discovered that it is possible to increase the data rate for certain DMA transactions between I/O units and shared memory and at the same time very efficiently utilize the CPU bus by transmitting particular types of DMA transactions between I/O and shared memory either directly to shared memory or directly to the CPU bus. My method increases the data rate for certain types of DMA transactions and very efficiently utilizes the CPU bus thereby increasing overall system performance.
[0014] In the preferred embodiment of the invention, a general purpose computer system is used to assign two memory address ranges to the I/O bus address space. When the I/O device generates a DMA transaction request, a system controller that has been programmed to recognize the memory address ranges forwards requests with addresses that correspond to a particular range directly to either a CPU bus or to a memory controller.
[0015] In another embodiment of the invention, the general purpose computer only assigns one memory address range to the I/O bus address space and the system controller forwards all DMA requests with addresses that correspond to the range directly to the CPU bus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a block diagram of a general purpose computer system;
[0017] FIG. 2 is a block diagram of the I/O interface device incorporated into a general purpose computer system;
[0018] FIG. 3 a is a flow chart describing a DMA read transaction;
[0019] FIG. 3 b is a continuation of the flow chart of FIG. 3 a; and
[0020] FIG. 3 c is a continuation of the flow chart of FIG. 3 b.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] FIG. 1 is a high-level block diagram of a general-purpose computer system 10 , hereinafter referred to as the computer system, which can be employed to implement the novel DMA transaction process described by this application. Such a computer system will typically have one or more central processing units (CPUs) 11 a, b, and c, and associated cache memory in communication with a CPU bus 22 . The CPU(s) enable much of the computer system's functionality. Among other things, they make and compare calculations, signal I/O devices to perform certain operations, and read and write information to memory. The cache associated with each CPU acts as a buffer, local to each CPU, for the storage of a version of data contained in the shared memory 40 . Cache provides a mechanism for each CPU to very rapidly access a version of data that is contained in shared memory without using any CPU bus cycles. The CPU could be, for instance, a MPC7410 Power PC processor sold by the Motorola Corporation.
[0022] Continuing to refer to FIG. 1 , a system controller 30 is in communication with the CPU bus 22 , with shared memory 40 , and with one or more I/O buses 52 & 53 . Generally speaking, the system controller acts as a communication interface between the CPU bus 22 , the I/O bus(s) 52 and 53 , and the shared memory 40 . All transactions directed to the shared memory from either the CPU bus or from the I/O buses are processed by the system controller. The system controller that I used in the computer system is the GT64260B system controller, sold by Marvell Semiconductor, Inc. but almost any other system controller could be used that provides similar functionality. A more detailed discussion of the system controller functionality will be undertaken later in this application with reference to FIG. 2 .
[0023] Continuing to refer to FIG. 1 , the I/O bus used in my implementation conforms to the PCI bus standard. Generally, the I/O bus serves as a way of expanding the computer system and connecting new peripheral devices, which are in this case represented by the external I/O devices. To make this computer system expansion easier, the industry has developed several bus standards. The standards serve as a specification for the computer system manufacturer and the external I/O device manufacturer. There are many I/O bus standards that can be utilized in the computer system described in this application, but for the purpose of explanation, I will refer to the well-known PCI bus standard. The I/O devices 50 and 70 are in communication with the I/O bus 52 . These I/O devices could be disk drives, multimedia devices, network interface devices (NIC), printers, or any other device that provides information to and requests information from the computer system and which do not contain cache memory. Typically, I/O devices operate under the general control of the CPUs and the operating system. Alternatively, there could be more than one I/O bus incorporated into the computer system. I/O bus 53 , could also adhere to the PCI bus standard or another I/O standard. Alternatively, but not shown, either or both bus 52 and 53 could be processor buses that support communication between one or more CPUs and non-cachable I/O devices In this case, I/O requests could be generated by either an I/O device or by one of these CPUs on behalf of an I/O device.
[0024] The shared memory 40 in this case is the MT48LC32M8 SDRAM sold by Micron Technology, Inc., although any type of random access memory, supported by the system controller could be used. The shared memory provides a single address space to be shared by all of the CPUs in the computer system and it stores data that the CPUs use to make calculations and operate the computer system and stores data that the external I/O devices can use or modify.
[0025] FIG. 2 represents a block diagram of the system controller 30 with associated CPU bus 22 , CPU and cache 20 , I/O buses 52 & 53 , I/O device 50 , and I/O processor 60 . Going forward, I will refer to both the I/O device 50 and the I/O Processor 60 as I/O devices. The system controller 30 , surrounded by a dotted line, incorporates a range of functionalities including, among other things, CPU and I/O bus interface logic 310 and 320 respectively, memory control 330 , CPU bus arbitration 370 , cache coherency in the form of a snoop address decoder 350 , and system control registers 360 . All of the system controller functionality, with the exception of the CPU arbitration 370 , is connected to the system controller Bus 340 . The system control registers 360 are used to control the behavior of all aspects of the system controller 30 . These registers are typically programmed once by software at initialization of the computer system 10 , however, some or all of the control registers 360 can be modified during the computer system operation. For example, certain system controllers can be programmed to control the size of DMA read requests, or decode interrupt signals, or signal interrupt completion.
[0026] In general, system controllers are available that are designed to be used in multiple standard modes of operation. Two standard modes are the non-coherent and coherent modes. The non-coherent mode is well suited to move large amounts of data between I/O devices and shared memory very rapidly while the coherent mode is better suited for processing housekeeping-type transactions which are typically small transactions dealing with the properties of data as opposed to the data itself. For example, housekeeping transactions could contain status information such as packet received or sent, checksum information, or information about the next DMA transaction. These housekeeping types of transactions might not be directly controlled or generated by an application program. Housekeeping type transactions should be exposed to the coherency protocol mentioned earlier. The Marvell Corporation GT64260B system controller product manuals explain how the controller can be programmed to enable both of these standard operational modes.
[0027] More specifically with reference to FIG. 2 , the CPU bus interface logic 310 incorporates CPU master unit 311 and CPU slave unit 315 . As these units suggest, the system controller can operate as a CPU bus master or CPU bus slave, depending upon which system resource generates the transaction request. The CPU master unit 311 , among other things, performs read, write, and cache coherency operations on the CPU bus at the direction of the PCI bus interface logic 320 or the memory controller 330 . The CPU slave unit 310 , among other things, decodes CPU bus signals to detect requests in assigned memory address ranges, forwards these requests to the memory controller or the PCI interface logic, for instance, and drives CPU bus signals to provide data and signal completion in compliance with the CPU bus protocol.
[0028] Continuing to refer to FIG. 2 , the CPU master unit 311 incorporates a read and a write buffer 312 and 313 respectively. The CPU master read buffer 312 stores up to four read requests that it receives from other system controller units. The read buffer operates to increase multiple read transaction efficiency by allowing multiple read transactions to be in progress simultaneously. The CPU master write buffer 313 functions to store write requests from other computer system resources (i.e., CPUs, I/O, or memory controller) until the requesting unit or device is ready to service the request. The write buffer 313 can store up to four write requests. The CPU slave 315 generally provides address decoding, buffers read/write transactions, forwards requests to other resources in the computer system, and drives CPU bus signals to provide data and signal completion in compliance with the MPC7410's CPU bus protocol. Specifically, the CPU slave unit incorporates a read buffer 316 , a write buffer 317 , and an address decoder 318 . The CPU slave read buffer unit buffers read data from a computer system resource until the CPU is ready to accept it. Up to eight read transactions can be buffered in this manner. The CPU slave write buffer 317 is utilized to post write transactions, that is, the write address and data can be stored in this buffer until the requested computer system resource is ready to perform the write transaction. The CPU slave write buffer can post up to six write transactions. The CPU slave address decoder 318 associates memory address ranges with other computer system resources, for instance, an I/O device and it controls how certain transactions will be performed.
[0029] The PCI bus interface logic 320 incorporates the PCI address decoder 325 and the PCI read and write buffers numbered 322 and 323 respectively. The PCI bus interface logic can be programmed to decode I/O bus signals in order to detect requests from I/O devices in assigned memory address ranges, forwards these requests to other computer system resources, and drives I/O bus signals to provide data and signal completion in compliance with the PCI bus protocol. In compliance with the PCI specification, the registers that control the interface logic are accessible via the so-called PCI configuration space. Also, as previously mentioned, certain properties of the PCI interface logic are controlled by the system controller registers 360 . Alternatively, the PCI interface logic could be programmed to decode processor bus signals if a processor bus instead of an I/O bus was incorporated into the computer system 10 .
[0030] In the preferred embodiment of the invention, the PCI address decoder 325 operates to decode I/O bus signals in order to detect a request from I/O devices in two assigned memory address ranges. These address ranges correspond to addresses on the I/O bus at which I/O devices expect to access the shared memory. Depending upon the I/O request address detected, the interface logic forwards the request directly to either the memory controller unit or the CPU master unit. For example, a first memory address range could be assigned to all transactions that contained only data information and a second memory address range could be assigned to handle DMA requests that contained housekeeping information. In this case, the PCI address decoder is programmed to operate such that DMA requests detected in a first memory address range will cause the request to be forwarded directly to the memory controller 330 in a non-coherent manner and DMA requests detected in a second memory address range will cause the request to bypass the standard system controller coherency functionality and be forwarded directly to the CPU master 311 in the coherent manner suggested by my invention. The Marvell system controller product manuals contain enough information so that someone skilled in the art of computer design having read this description would be able to understand how to program the address decoder to operate in the manner described above. The preferred embodiment of the invention enables the computer system to take advantage of the efficiencies associated with processing DMA requests containing address information on the CPU bus 22 and the efficiencies associated with sending DMA requests containing only data directly to the memory controller.
[0031] In another embodiment of the invention, a single memory address range is assigned to handle all DMA requests from a particular I/O device. In this embodiment, the PCI address decoder is programmed to operate such that all DMA requests detected in the assigned memory address range will cause the request to be forwarded to the CPU bus interface logic which then propagates the request onto the CPU bus 22 where it is exposed to the cache coherency protocol. This method for processing DMA requests is particular advantageous when the request contains housekeeping-type information as it is important that this type of request be exposed to the cache coherency protocol. Placing this type of request onto the CPU bus is the most efficient method for processing them in a coherent manner and speeds up the overall operation of the computer system.
[0032] The one or more assigned memory address ranges could be of almost any size, limited only to the amount of shared memory assigned to any particular I/O device. It should be understood that the addresses contained in any particular address range do not have to be compact or contiguous. So, for example, if a range was composed of some number of smaller blocks of compact memory addresses, these number of blocks would be considered to be a single, logical memory address range.
[0033] So in the preferred embodiment of my invention, the shared memory could be mapped to an I/O device such that DMA requests with addresses corresponding to the last sixteen Mbytes of a two hundred and fifty six Mbyte block of shared memory space would be forwarded directly to the memory controller and DMA requests with addresses corresponding to the balance of the two hundred fifty six Mbytes (0-239 Mbytes) would be forwarded directly to the CPU bus 22 . In another embodiment, the memory could be mapped to an I/O device such that all DMA requests with addresses corresponding to any address in the entire two hundred and fifty six Mbyte block of shared memory space would be forwarded to the CPU bus.
[0034] The PCI target read buffer 322 is used by the computer system to support a type of pipelined read transaction. Under certain circumstances, the PCI target may have forwarded one or more read transactions to a computer system resource even though there is no active PCI bus read transaction in progress. Delayed reads and read prefetches are two such circumstances that would result in read transactions being buffered at the target read buffer. Read prefetches are typically used to speculatively bring data into the read buffer before the data is actually referenced. Read prefetches increase performance and decrease latency when large blocks of data are read and are recommended to be used with my invention.
[0035] The PCI target write buffer 323 is used to post write transactions. Specifically, the write address and data can be stored in the write buffer until the requested computer system resource is ready to perform the write. This allows the PCI target to terminate the bus cycle earlier, freeing the bus for other operations. Up to four write transactions can be posted by the write buffer.
[0036] The memory controller 330 accepts read and write transactions from the CPUs and from the I/O devices, manipulates the shared memory control, address, and data signals to perform reads and writes, and returns completion status and read data to the requesting computer system resource. The memory controller also generates coherency operations and forwards them to the CPU bus if these have been specified by the snoop address decoder 350 . The snoop address decoder is used to decode ranges of addresses on each bus that are subject to one of several types of coherency management.
[0037] As previously mentioned, with the exception of the CPU arbitration unit 370 , all of the system controller functional units are in communication with the system controller bus 340 . The CPU arbitration unit operates to resolve multiple simultaneous requests for the CPU bus 22 by, for example, any one of the CPUs 11 or another device on the CPU bus, or by the CPU master 311 .
[0038] An example of a DMA transaction that uses the preferred embodiment of my invention will now be described with reference to the DMA read transaction logical flow diagram of FIG. 3 a, b, and c. I have elected to describe a read transaction because my invention is particularly well suited to processing DMA read transactions in a very efficient manner. I will not describe a DMA write transaction in this application as I believe that it is obvious, to someone skilled in the art, how my invention would be utilized in this manner. The DMA transaction description that follows assumes that the PCI and CPU bus maps use the same base address for memory. Further, it should be understood that the steps and the sequence of the steps described with reference to FIGS. 3 a, b, and c could be different depending upon the system controller used and the manner in which the computer system registers are initialized. The following description is not meant to limit the scope of my invention to this embodiment only.
[0039] At Step 1 , the computer operating system programs the PCI address decoder 325 to discriminate between two memory address ranges and it programs the CPU slave decoder to respond to all shared memory addresses. The computer operating system also programs the CPU's cache to only cache data associated with the memory address range that corresponds to an I/O transaction processed in a coherent manner. The above two ranges are pre-selected by the user. Typically, the computer operating system would be able to run some routines in order to determine the address ranges used for certain types of DMA transactions, i.e., data or housekeeping transactions. These ranges may be identical on the CPU and 1 , 0 buses or the I/O bus addresses may be mapped to equivalent ranges of CPU addresses.
[0040] Step 2 starts when the DMA engine 520 associated with I/O device 50 on the I/O bus 52 generates a read request and drives it onto the I/O bus. Typically this would be a burst read. It should be understood that any device on either I/O bus 52 or 53 could generate a DMA read request and I only refer to a particular I/O device on a particular bus for the purpose of illustration. The process whereby a computer system operates to control DMA functionality by an I/O device will not be explained here as this is well know to those skilled in the art of computer software design. This read request could contain housekeeping information, it could contain data information, or it could contain both housekeeping and data information.
[0041] In Step 3 , the PCI interface logic 320 detects the read request on the I/O bus 52 and passes the request to the PCI address decoder 325 . As mentioned previously, the PCI address decoder operates to associate ranges of I/O addresses with computer system resources. In the preferred embodiment shown in FIG. 3 , the address decoder is programmed to associate I/O addresses with either a first or a second memory address range but in another embodiment of the invention, there could be only a single memory address range.
[0042] In Step 4 , the address decoder operates to associate the I/O address with the first memory address range or not. If the I/O address corresponds to the first memory address range, the process continues to Step 5 , otherwise it proceeds to Step 5 a.
[0043] At Step 5 , the PCI interface logic 320 checks to see if the requested read data is already buffered in PCI read buffer 322 , due to any prefetching operation conducted by the computer system. If so, then the transaction jumps to Step 13 , if not, then the interface logic proceeds to terminate the bus transaction with retry. Retry makes the PCI bus available for other transactions until the read data is ready. The DMA engine will keep retrying the request until read data is available. At the same time that the interface logic generates a retry, the DMA request is sent directly to the CPU Master 311 in Step 6 .
[0044] In Step 7 , after receiving the DMA request, the CPU master 311 signals the arbitration unit 370 to arbitrate for the CPU bus 22 . In Step 8 , the arbitration unit generates control signals that make the CPU bus available to the CPU master unit or if not, keeps arbitrating for the CPU bus. Assuming that arbitration for the CPU bus is successful, then in Step 9 the CPU master unit performs a read transaction, typically a burst read, at the address specified by the request. Continuing to refer to Step 9 , the CPU's coherency protocol observes the transaction request address and enforces coherency. It may be necessary at this point, depending upon the result of the coherency operation, to interrupt or terminate the bus cycle to write data cached at a CPU back to shared memory. The system controller I used requires that the CPU be run in a mode where the cycle is retried after cached data is written to memory. Other system controllers and/or CPU's may be able to perform the memory update simultaneously with the read cycle. If the cycle is terminated, as in Step 10 , the process would go back to Step 7 and the CPU master would rerun the cycle. If the cycle was not terminated, the process would proceed to Step 11 .
[0045] In Step 11 , the memory controller 330 drives suitable signals to read the requested data from shared memory 40 , drives the data onto the CPU bus 22 , and signals that the data is ready. In Step 12 , the CPU master 311 receives the data and sends it to the PCI interface logic 320 or the CPU master might temporarily store the data in the read buffer 312 until the PCI interface logic is ready to accept the data. Referring to Step 12 , if the PCI interface logic 320 has buffered additional read requests, the process returns to Step 4 and the read request would be processed as before in parallel with Step 14 . Regardless, the process proceeds to Step 14 , and when the PCI interface logic has collected enough data to satisfy all or a programmatically-specified portion of the original read request, the PCI interface logic drives the data to the I/O bus 52 and signals that the read transaction is complete. At Step 15 , the requesting I/O device captures the data driven by the PCI interface logic and issues a new read request if the original request has been only partially completed.
[0046] Now returning to Step 4 , if the I/O address does not correspond to the first memory address range, the PCI address decoder 325 associates the I/O address with the second memory address range and then, in Step 5 a checks to see if the requested data is already buffered in the PCI read buffer 322 . If not, then the PCI interface logic 320 proceeds to terminate the read transaction on a retry and at the same time sends the read request directly to the memory controller 330 . The memory controller processes the read request in a manner similar to that of Step 11 except that the CPU bus and the coherency protocol is not involved. After the requested data has been fetched, the memory controller drives the data back to the PCI interface logic and the process proceeds to Step 14 .
[0047] The embodiments of my invention described in this application are not intended to be limited to single CPU or I/O bus implementations, nor is my invention limited to one or two memory address ranges. I can foresee that a system controller could operate in modes that would permit the definition of three or more memory address ranges that could be used to further improve computer system DMA processing performance. | The data rate at which DMA transactions are processed by a General Purpose Computer System can be significantly improved by directing housekeeping type transactions directly to the CPU bus and by directing data type transactions directly to Shared Memory. By assigning memory address ranges to particular I/O devices and by programming PCI Interface Logic on a System Controller to detect these ranges and to direct DMA requests directly to either the CPU bus or to the Memory Controller depending upon the address range detected, the speed with which DMA transactions can be processed is enhanced. | 6 |
This is a continuation of U.S. application Ser. No. 07/979,797, filed Nov. 19, 1992 now abandoned which, in turn, is a division of application Ser. No. 07/859,833, filed Mar. 30, 1992 (which issued on Apr. 20, 1993 bearing U.S. Pat. No. 5,203,392.
FIELD OF THE INVENTION
The present invention relates to a rolling door combined with a mechanism which controls the raising and lowering of the door. The so-called "rolling door" comprises a curtain including a plurality of interconnected relatively pivotal horizontal slats and a pair of vertical guides positioned on both sides of the curtain for guiding the curtain for vertical movement between a first or raised position and a second or lowered position. More particularly, the mechanism is used to regulate the raising and lowering of a rolling fire door. During normal ambient conditions, the mechanism holds the door open; however, if a fire occurs, the mechanism releases the fire door permitting a regulated closing of the door to secure the opening and to prevent the fire from spreading from one location to another.
SUMMARY OF THE INVENTION
This invention addresses the need for a mechanism which can control the opening and closing of a door, particularly a fire door. The present invention is such a mechanism comprising a speed reduction gearing, a governor, and a brake combined with a rolling fire door. The mechanism, by itself, controls the speed of the door when it is closing under the gravitational pull on the door. Additionally, a motor or a hand chain assembly which is manually operated, may be attached to the input shaft of the mechanism to further control the opening and closing of the door.
BACKGROUND OF THE INVENTION
Operating mechanisms to control the raising and lowering of doors have been used for many years. Among the doors so controlled are fire doors including fire doors of the type comprising a plurality of horizontal slats pivotally connected to one another to enable the fire door to be reeled in when raised and unreeled when lowered. There are numerous prior art mechanisms known and used for raising and lowering such fire doors both in normal or non-emergency conditions and during a Fire. In such operating mechanisms, electric motors are commonly included to raise the door. However when a fife occurs, these operating mechanisms disengage the motor from the fire door and allow the door to close either under the urging of an auxiliary spring activated by mechanical means or by the gravitational pull on the door resulting from the release of tension from a torsion spring counterbalancing mechanism. Previously known fire doors primarily rely on mechanical means such as pendulum or oscillating governors, friction discs operating in viscous fluid baths, mechanical ratchets, cams or arms to release the fire door and govern its descent to secure the opening. However, these devices are unreliable because they often jam or cease functioning while the door is descending. The torsion spring counterbalancing mechanisms are also unreliable, expensive and difficult to adjust to assure that the door will move downwardly at a safe rate to a secure closed position. Centrifugally operative break type governors have also been employed to control the downward velocity of a fire door. However, such governors have always acted in conjunction with a low speed shaft connected to the door, which low speed shaft is difficult to control by devices responsive to centrifugal force. These problems are compounded by the fact that repeated use of the auxiliary springs and the springs in the counterbalancing mechanism often result in deformation due to excessive heating, as during a fire, and to general mechanical fatigue. Therefore, the need exists for an improved fire door operating mechanism for regulating the raising and lowering of the door which effectively controls the fire door's movement without the need of springs or unreliable mechanical means.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiment of the invention will be explained in further detail and in reference to the drawings, in which:
FIG. 1 is a perspective view of a rolling fire door and a regulating mechanism embodying the present invention with some pans broken away in order to reveal other parts;
FIG. 2 is a sectional view in enlarged scale of the mechanism shown in FIG. 1 taken along line 2--2 in FIG. 1;
FIG. 3 is a cross-sectional view of a releasing mechanism taken along line 3--3 in FIG. 2;
FIGS. 4 and 5, when taken together with FIG. 4 on the left make up an exploded perspective view of the interior of the regulating mechanism;
FIG. 6 is a schematic cross-sectional view of the door in a closed position; and
FIG. 7 is a schematic cross-sectional view of the door in an open position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention relates to a rolling door combined with a mechanism which controls the raising and lowering of the door. More particularly, the mechanism is used to regulate the raising and lowering of a fire door and is shown in FIGS. 1 to 5 and is generally designated by the reference numeral 10. The regulating mechanism 10 combined with a fire door 12 comprises a fire door assembly 14.
FIG. 1 shows a fire door 12 which comprises a curtain 16 including a plurality of interconnected relatively pivotal horizontal slats 18, which are kept in alignment by endlocks 20. As shown and presently preferred, endlocks 20 lock each end of alternate slats to act as a wearing surface, to maintain slat alignment and to retain the curtain 16 when there are wind pressures in a pair of vertical guides 22, here shown as channels, positioned on either side of the curtain 16. Other forms of endlocks may be employed. The pair of vertical guides 22 are for vertically guiding the movement of the slats 18 inside the guides 22 to a first or raised position (FIG. 7) and to a second or lowered position (FIG. 6). While the preferred embodiment for the fabrication of the slats 18 of the curtain 16 is either galvanized or stainless steel, other fireproof or fire retardant materials may be used without departing from this invention, such as, for example, materials according to Underwriters Laboratories (UL) and/or National Fire Protection Association (NFPA) requirements. The guide 22 is secured to a wall or door frame or other structure 28 by a mounting angle 26. Since the guides 22 are preferably made of metal or the like, they are slotted to allow for heat expansion of the metal when a fire occurs to prevent the guides 22 from deforming and making the fire door nonfunctional. As shown and presently preferred, at the bottom of the curtain 16, two angles 30a and 30b are attached to the bottom slat 32 to form a bottom bar 34 to reinforce the bottom of the curtain 16 (FIG. 6). Like the guides, be bottom bar 34 is slotted to provide for the heat expansion of the metal.
The top of the curtain 16 is fixed to a horizontally elongated rotatable member 36 for winding and unwinding the curtain 16 around the member 36 to respectively raise and lower the curtain 16. (See FIGS. 6 and 7) In its preferred embodiment, the elongated rotatable member 36 is a hollow barrel, tube or shaft. The member 36 may also be a solid or partially solid member, tube, shaft, barrel or the like. The curtain 16 is shown as connected to the rotatable member or barrel 36 by a starter slat 38. In its preferred embodiment, the barrel 36 is supported by at least two plugs 40 with one being inserted at each end of the barrel 36. The barrel 36 could also have a shaft or tube extending the entire length of the barrel. Although the present invention does not require any type of spring such as a torsion spring counterbalancing mechanism to assist the closing of the door 12 under gravitational pull, a torsion spring my be incorporated within the barrel 36 to act if necessary as an additional closing means. The shafts 42 of the plugs are then attached to endplates 44 to provide support for the barrel 36. Ball bearings (not shown) positioned in the endplates 44 enable the shafts 42 of the plugs 40 to rotate. The endplates 44 are mounted to the mounting angle 26 which is secured to the wall 28. A hood 46 which is typically a sheet metal housing, is mounted horizontally between the endplates 44 and secured to a lintel 48 which is a horizontal member spanning and carrying the load above an opening for a fife door and usually constitutes a pan of a wall, beam or the like directly above the door opening. The hood 46 encloses the coiled curtain 16 to act as a fire stop by closing off the space between the coiled curtain and the lintel. A hood or fire baffle 50 (FIGS. 6 and 7) which is a hinged sheet metal piece within the hood 46 acts as an additional fire stop. A temperature sensitive actuator 88, such as a fusible link, releasably holds the baffle 50 in a raised position. However, during a fire, the fusible link will melt and release the baffle 50 which then drops down to close the space between the top of the curtain 16 and the hood 46 to prevent smoke and fire from passing under the lintel 48 and over the barrel 36.
The preferred embodiment of the present invention includes the regulating mechanism 10 mounted or attached to the right endplate 44 directly in front of the barrel 36 outside of the hood 46 (FIG. 1 ). Alternatively, the regulating mechanism 10 may be attached to either endplate and may be placed directly in front of the barrel 36, either under or outside of the hood or in axial alignment with the rotatable member 36. For reasons that will become apparent hereinafter, additional speed reduction gearing would be preferably included if the regulating mechanism 10 was axially aligned with the rotatable member 36. The preferred embodiment for the means for operatively connecting the rotatable member 36 to the output shaft 56 of the regulating mechanism 10 comprises a chain drive (FIG. 2). The chain drive 54 includes one or more drive sprockets 58 used in connection with a like number of roller chains 60 and may have a variety of configurations. In the present embodiment, a large drive sprocket 52, is attached to the plug shaft 42 and a small drive sprocket 62 is attached to the output shaft 56 of the regulating mechanism 10 with the sprockets 62, 52 being in driving relation by a roller chain 60. In the present embodiment, the chain drive 54 creates a 5 to 1 ratio between the output shaft 56 of the regulating mechanism 10 and the shaft 42 of the plug 40 thereby decreasing the speed of the rotatable member 36 in order to control the winding and unwinding of the curtain 16. It is to make up for the omission of this 5:1 ratio that additional reduction gearing is preferred when the mechanism 10 is aligned with the rotatable member 36.
The preferred embodiment of the regulating mechanism 10 is shown in FIGS. 2 to 5. The preferred embodiment of the present invention has means for rotating the input shaft of the regulating mechanism. This rotating means may comprise a motor 64 having a high-starting torque, a conventional hand chain assembly 66, hand crank (not shown) or the like. The motor 64 may be a constant-speed, multi-speed, adjustable-speed or varying-speed motor or the like. Additionally; the motor 64 may be driven pneumatically, electrically or hydraulically. Under normal operation, power is fed to the motor 64 via a control box (not shown). Also an additional electrical power source for the motor 64, such as a generator, battery or the like (not shown), may be connected to the motor to provide auxiliary power in case of a power failure. As shown and preferred, the drive shaft of the motor 64 (not shown) passes through the hand chain assembly 66 to drive a shaft 68 engaging a coupling 76. The shaft 68 drives the coupling 76 to in turn drive an input shaft 78 which passes through a cylindrical hole 80 of the means for releasing a brake 82 and in a support plate 85 for the releasing mechanism 82. The input shaft 78 drives an output shaft 56 of the regulating mechanism 10 in order to raise or lower the fire door 12.
The releasing mechanism 82 is housed in the sheet metal cylindrical covering or housing 86 which is axially aligned and attached to a hand chain assembly 66, the function of which will be described below (FIG. 4). The releasing mechanism 82 comprises a sash chain 90 connected to a temperature sensitive means 88 such as a fusible link or the like (FIG. 3). The fusible link as shown comprises two pieces of metal held together by low melting-point solder. While the fusible link is intact, the sash chain 90 pulls a plunger 106 of a plunger mechanism 92 to compress a compression spring 104 inside a plunger mechanism 92 to prevent the plunger 106 from contacting a lever 98 (FIG. 3). When the ambient temperature surrounding the fire door reaches a predetermined value, the low melting-point solder melts and the fusible link separates, releasing the tension on the sash chain 90. With this tension removed, the compression spring 104 releases the plunger 106 to engage the lever 98 to disengage the brake 84 (FIG. 4). The preferred embodiment for the brake is an electromagnetic brake of the shoe-type. Additionally, the brake may be magnetically, hydraulically or pneumatically operated or a combination of the above. Preferably, it is a continuous duty, spring-set, solenoid-activated brake. The brake 84 includes brake shoes 108 which are movable between a braking position and a released position, a movable chain 96 (FIG. 3) and means for moving the brake shoes between a braking and a released position or brake moving means 100 here shown in the form a brake cam. When the fusible link is replaced and the sash chain 90 retracts the plunger 106, the expandable spring 94 attached to the lever 98 pulls the lever 98 back, which in turn moves the brake cam 100 to its original position to reengage the brake 84.
As shown, the movable chain 96 provides another way of releasing the brake 84. The movable chain 96 is connected to the lever 98 which releases the brake 84 by movement of the brake cam 100. In the preferred embodiment of the present invention, the brake 84 is axially aligned and located directly under the release mechanism 82. The lever 98 is attached to a tension spring 94, brake cam 100 and a solenoid 102. When the lever 98 is pulled down by the movable chain 96, brake moving means or cam 100 pivots to disengage the brake shoes 108 of the brake 84 to allow the input shaft 78 to rotate and permit the fire door 12 to rotate.
Yet another way to disengage or engage the brake 84 here optionally included is by the lever 98 being moved by the solenoid 102. When the fire door 12 is in a raised or open position, the brake 84 is engaged and the solenoid 102 is in an "open" position. An electric signal may be seat to the solenoid 102 by a control box (not shown) to actuate the solenoid 102 to a "closed" position. This disengages or releases brake 84 to permit the door to move to its closed position. When the fire door 12 thus closes, the signal to the solenoid 102 is reversed by the operation of a limit switch to be described hereinafter and the solenoid 102 releases the lever 98 which in turn reengages the brake 84.
By engaging or disengaging the brake 84, the input shaft 78 of the regulating mechanism 10 is either held stationary or allowed to rotate, respectively. When the brake 84 is engaged and the brake shoes 108 are in a brake position, the brake shoes 108 are engaging a cast iron barrel 110 which surrounds the brake shoes 108 and which is attached to and rotates the input shaft 78. The brake shoes 108 hold the cast iron barrel 110 stationary which in turn prevents the input shaft 78 from rotating. When the brake 84 is released, the brake shoes 108 are in a released position and are not engaging the iron barrel 110. This allows the iron barrel 110 to rotate which in turn allows the input shaft 78 to rotate. Attached to the cast iron barrel is a governor 112 which is a mechanical device that limits the rotational speed of shaft 78 and barrel 110 to thereby control the speed of descent of the door during automatic closure. In its preferred embodiment, the present invention comprises a centrifugal governor 112 preferably including two brake shoes 114 which are connected to each other at a pivot point 116 and are connected to shaft 78 and drum 110 as by a pin 111 to rotate therewith. Two tension springs 118 hold the brake shoes 114 in a closed position until the input shaft 78 is rotated at or above a preset speed at which point the brake shoes 114 begin to separate due to centrifugal force and thus apply a braking friction against the inside of a housing 120 to slow the speed of the input shaft 78. Thus, for example, the governor may be set to operate when the input shaft 78 rotates in excess of 1700 revolutions/rain (RPM) to prevent the input shaft 78 from exceeding that rotational speed. Additionally, the governor may operated pneumatically or hydraulically.
The input shaft 78 is then connected to a splined shaft 122 which drives a speed reduction gearing 124. The speed reduction gearing 124 may be of any suitable type but, as shown and preferred, comprises a planetary gearing assembly 126 which is housed in a gear housing 128 having its internal surface toothed to mesh with the planetary gears 132 and 138. The planetary gearing assembly 126 creates a large gear ratio of the order of 77:1 between the input shaft 78 and the output shaft 56 thereby decreasing the speed of the output shaft 56 to approximately 22 RPM, assuming the speed of input shaft 78 is 1700 RPM. Of course, other selected maximum speeds for the input shaft 78 will result in either a lower speed for the output shaft, or the use of a different gear ratio in the planetary gearing or some combination thereof as design criteria mandates. Additionally, the planetary gearing assembly 126 can be driven forward or backward unlike conventional worm gear or helical gear units which can not be driven backwards in this design configuration. The preferred embodiment of the present invention includes at least two sets of axially aligned planetary gearing, with the sun gear being a splined shaft 122 with at least 3 planet gears 132 surrounding it. The splined shaft 122 is connected to and rotates a drive plate 134 which in turn engages another splined shaft 136 which in turn rotates another set of planet gears 138 which in turn drives a drive plate 140. The low speed output shaft 56 is connected to the drive plate 140.
A limit switch sprocket 144 is connected to the low speed output shaft 56 which extends through a base 146 to engage the drive sprocket 62 of the chain drive 54. The regulating mechanism 10 is then mounted to the fire door 12 by the base 146 which preferably has three bolts for attachment to the fire door 12 to allow the base to move easily. The limit switch assembly 152 controls the extent of upward and downward movement of the fire door 12 and is driven by the limit switch rolling chain 148. The output shaft 56 rotates the limit switch sprocket 144 which in turn drives a limit switch sprocket rolling chain 148 to rotate a second limit switch sprocket 154 to engage the limit switch assembly 152 so that the upward and downward movement of the curtain 16 is controlled.
This configuration of the chain drive 54 and the speed reduction gearing regulates the speed of the door 12 closing and opening. The chain drive 54 which is placed between the regulating mechanism 10 and the rotatable member 36 of the door 12 has a speed reduction ratio of for example 5 to 1 and the planetary gearing assembly 126 has for example a speed reduction ratio of 77 to 1. Therefore the total speed reduction ratio between input shaft 78 and the rotatable member 36 to control the raising and lowering of the door 12 results in a 385 to 1 mechanical advantage thereby resulting in a reduced power requirement to raise and lower the door 12. However, with the governor on the high speed end of the power train, its regulation is sensitive and precise.
The regulating mechanism 10 may also be configured with the motor 64 being placed between the speed reduction gearing and the governor to control the raising and lowering of the curtain. This will not adversely affect the operation of the door as the governor will continue to act on the high speed portion of the power train. Additionally, the brake may be placed either before or after the speed reduction gearing of the regulating mechanism without adversely affecting the operation of the door as the brake will continue to prevent the output shaft of the regulating mechanism from rotating when the brake is engaged and allow the output shaft to rotate when it is disengaged.
Operation
If a fire occurs with the fire door in its raised position, the fusible link 88 melts, releasing the sash chain 90 which releases the plunger 106 by decompressing the compression spring 104. The plunger 106 pushes the lever 98 to engage the brake moving means or cam 100 to release the brake 84. Once the brake 84 has been released, the cast iron barrel 110 is released and the input shaft 78 is free to rotate as is the entire power train. This permits the door to start moving downwardly under the urging of gravity. As the door moves down, it rotates the elongated member 36 which through the chain drive 54 rotates shaft 56, which through planetary gearing 132 and 138 rotates shaft 78 and drum 110 at a high speed. In the preferred embodiment of the present invention, the governor 112 regulates the speed of the input shaft 78 once the input shaft 78 begins to rotate at a speed of 1700 RPM and maintains the input shaft 78 speed at slightly over 1700 RPM allowing the fire door 12 to close at a very gradual speed to prevent injury to escaping personnel and damage to the door. Additionally, during the closing of the door, the regulating mechanism 10 does not disengage the motor 64 from the door 12. The motor 64 remains connected and thus operatable to open or close the door if there is electrical power available.
Once the door is in its lowermost position, the raising of the door is easily accomplished by operating a control panel to energize the motor to raise the door without the need for any adjustments or manipulations of the equipment or regulating mechanism other than resetting the door by pulling the sash chain 90 which in turn pulls the plunger 106 of the plunger mechanism 92 away from the lever 98 and replacing the fusible link 88 to hold the sash chain 90 in place. As will be described in greater detail hereinafter, the ordinary control mechanism for the motor (not shown), would preferably include an "Up" button, a "Down" button and a "Stop" button, which buttons, through conventional control means will operate the polarity of energization of the motor so as to cause it to rotate in an "Up" direction or a "Down" direction. In a lowered position, when the "Up" button is actuated, the motor 64 will be actuated to move the door upwardly. When the door 12 moves to the uppermost position, the limit switch assembly 152 will operate to de-energize the motor and to reset the solenoid control brake 84 and thereby relock the door in the up or raised position.
The present invention may also be used for a door that is capable of high cycle operation, i.e., 50,000 to 100,000 cycles or runs. A control box (not shown) may be connected to the motor 64 to allow the regulating mechanism 10 to raise and lower the door. A control station for the control box, including buttons, switches or the like, may comprise an "Up" button, a "Down" button and a "Stop" button. When the "Up" button on the control panel is pressed or engaged, the control box sends a signal to the solenoid 102 which releases the brake 84. The brake 84 disengages the input shaft 78 to allow the motor 64 to drive the input shaft 78 which in turn drives the regulating mechanism 10 to drive the output shaft 56 to wind the curtain 16 around the barrel 36 of the door. When the "Down" button is pressed the motor 64 drives the shafts and the regulating mechanism 10 in the opposite direction to unwind the curtain 16 from the barrel 36 until the curtain 16 closes. When the curtain 16 reaches a predetermined limit due to the configuration of the limit switch assembly 152, the power to the motor 64 is cut off and a signal is sent to the solenoid 102, which re-engages the brake 84. The door stops at an open position or closed position because of the limit switch assembly 152. The stop button or switch can stop-the motor 64 from either raising or lowering the curtain 16.
In emergency situations, the hand chain assembly 66 can operate the door 12 during a power failure or removal of the motor 64 for inspection or servicing. The hand chain assembly 66 is activated when a lever chain 74 is pulled to engage a lever 72. The lever 72 activates the hand chain assembly 66 so that a hand chain 70 can then be pulled to rotate the shaft 68 of the coupling 76 to rotate the input shaft 78 of the regulating mechanism 10.
Additionally, a safety edge device may be incorporated with the bottom bar 34 so that in the event a person was beneath the door as it was closing, the safety edge device would be triggered and would immediately reverse the door to the open position momentarily and then again permit the door to begin its descent to secure the opening from a fire. The safety edge device would continue to work so long as electrical power is provided to the motor. It is for this reason among others that auxiliary power may be desirable.
It should be understood that the preferred embodiments and examples described are for illustrative purposes only and are not to be construed as limiting the scope of the present invention which is properly delineated only in the appended claims. | A mechanism for controlling the raising and lowering of a door comprising a speed reduction gearing, a high speed input shaft and a low speed output shaft connected to the gearing, and a governor mounted on the input shaft for regulating the input shaft's rotational speed. More particularly, the mechanism is provided with a brake having a movable brake shoe, a temperature sensitive link and an elongate member having a central portion coupled to the brake shoe. As well, the first portion of the elongate member is engageable with the temperature sensitive element and a second portion of the elongate member is engageable with the actuator. In this way, the elongate member is provided for moving the brake shoe to the release position in response to one of (1) the temperature sensitive link upon the temperature reaching a predetermined temperature and (2) the actuator. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to liquid metering apparatus generally and more particularly to an apparatus for supplying a liquid additive to a flow of liquid. The device according to this invention uses the flow of a liquid to enable a specific quality of additive to be injected into said liquid.
DESCRIPTION OF PRIOR ART
The prior art utilizes a reciprocating pump to inject an additive fluid into the main fluid that drives the reciprocating pump. However such pumps operate on only one-half of their reciprocating motion and contrary to the present device which injects like amounts of additive fluid on both the up stroke and downstroke of the reciprocating motion.
Prior art devices of the reciprocating pump type which are powered by a first fluid to power the additive fluid also are so structured so that upon failure of a part and loss of reciprocating movement blocks the flow of the first fluid so that if, for example, the device was being used as a poultry watering system, the blocked reciprocation would deprive the poultry of all water supply, whereas in the instant device, bypass valves become activiated which allows for continued flow of the primary fluid.
SUMMARY OF THE INVENTION
Flowing driving water enters the main pump and drives a water motor which in turn operates an additive pump which draws an additive liquid from a container and injects it into the flowing driving water as the later exits the pump. The additive pump and main pump are sized so as to give a certain ratio of additive liquid to the driving water.
The water motor comprises a housing having a diaphragm piston therein which is driven back and forth by diverting the flowing incoming driving water alternately from one side of the diaphragm piston to the other side thereof. The driving water is diverted from one side of the piston to the other side thereof by a system of inlet and outlet valves which are activiated instantaneously at the extremes of the piston stroke by an over-center spring mechanism.
When the incoming water drives the piston down, it forces water below the piston out of the pump through the outlet valves. When the piston reaches the bottom of its stroke, the over-center spring reacts and pulls the inlet and outlet valves up thus allowing incoming water into the bottom side of the piston. The piston is pushed up and water above the piston is pushed out of the outlet valves. When the piston reaches the top extreme of the stroke, the over-enter spring snaps in the opposite direction and pushes the inlet valves down again thus starting the cycle over again.
The additive pump consists of a double piston so as to inject an equal amount of additive fluid on the up and down stroke. The additive pump attaches to and is reciprocated by the up and down motion of the diaphragm piston and pumps one-half of the desired additive on the up stroke and one-half on the down stroke of the additive pump so that a continuous flow of additive fluid is pumped into the driving water at a location where it exits from the pump, so that the water within the driving pump is not contaminated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view in longitudinal section of a device according to the invention;
FIG. 2 is a cross sectional view taken along the lines 2--2 in FIG. 1;
FIG. 3 is a view in longitudinal section of a device according to the invention in another operative position; and
FIG. 4 is a cross sectional view taken along the lines 4--4 in FIG. 3.
DETAILED DESCRIPTION
Referring now to the drawings and Particularly FIGS. 1 and 2, the upstroke position of the pump 10 is shown. An inlet valve 12 is in its upper position in the pump body 11, in which position, a tapered valve seat 13, on the upper end of the valve 12, carrying an "o-ring" 14 is seated against a tapered shoulder 15 formed in the pump body 11. A valve stem 16 connects the upper tapered valve seat 13 to a lower tapered valve seat 17, carrying an "o-ring" 18, which at this time is spaced from a tapered shoulder 19 formed in the pump body 11. Flowing water enters the pump body 10 through a inlet line 20 and flows downwardly past the lower valve seat 17 and tapered shoulder 19 to fill a lower cavity 21 formed below a diaphragm piston 22, the periphery of which piston being secured in and sealed in the surrounding body portion 11 of the pump 10.
The water in cavity 21 forces the diaphragm piston 22 upwardly thereby forcing against any water above the piston from the downward stroke thereof, which will be hereinafter explained. The water above the diaphragm exits the pump body 11 through the upper end of an outlet valve 23. The upper end of the outlet valve 23 has a tapered shoulder 24 thereon carrying an "o-ring" 25 thereon, which at this time is spaced from a tapered valve seat 26, thereby allowing water to flow therepast and out though the outlet line 27. During the upstroke, the lower end of the outlet valve 23 has a tapered shoulder 28 thereon carring an "o-ring" 29 which at this time is seated against a tapered shoulder 30 formed in the pump body 11 thereby blocking the outlet line from any water entering the pump 10 through the inlet line 20 and present in the cavity 21. The outlet line 27 thereby drains the cavity 31 above the diaphragm piston 22 during the upstroke of the piston 22.
The diaphragm piston 22 has rigidly secured in the center thereof a vertically extending piston rod 32, which is mounted for vertical reciprocal movement in the pump body 11. As seen in FIG. 1, at the upper end of the piston rod 32 is pivotally secured the left end of a first linkage rod 33 by a pivot pin 34. Intermediate the ends of the linkage rod 33, the latter is pivotally mounted to the pump body 11 by a pivot pin 35. The right end of the linkage rod 33 is secured to the left end of a spring in the form of an "o-ring" 36. The right end of the o-ring 36 is secured to the upper end of a second linkage rod 38, by a pivot pin 37a, while the left end of the linkage rod 38 is pivotally mounted to the pump body 11 by a pivot pin 39.
The pivot pin 37a is mounted in a slot 40 formed in a valve bridge 41. The valve bridge 41 is secured to and joins the upper ends of valves 12 and 23. When the diaphragm piston 22 moves toward its upper position, from the position shown in FIG. 1 no immediate movement of the valve bridge 41 takes place, but when the piston 22 moves to its upper position, the linkage 33 and 38 joined by the spring o-ring 36 goes over-center and with a snap action takes the position shown in FIG. 3 thereby rapidly reversing the positions of the valves 12 and 23. Prior to going over-center the linkage 33 and 38 do not cause movement of the valves 12 and 23. Similarly, as seen in FIGS. 3 and 4, the over-center linkage 33 and 38 do not cause movement of the valves 12 and 23 on the down stroke until the piston 22 reaches its downward position.
Referring now to FIGS. 3 and 4, the downstroke position of the piston 22 is shown. The inlet valve 12 is in its lower position and its valve slot 13 and o-ring 14 are spaced from the shoulder 15. The lower valve seat 17 and its o-ring 18 are seated against the tapered shoulder 19. Flowing water enters the pump body 10 through inlet line 20 and flows upwardly past the valve seat 13 and tapered shoulder 15 to fill the upper cavity 31 formed above diaphragm 22 thereby forcing diaphragm 22 downwardly and forcing any water in cavity 22 out past the lower open end of valve 23 and out of the pump body through line 27.
Since the piston 22 only causes movement of the valve 12 and 23 through the action of the over center linkage 33 and 38, if the joining o-ring 36 breaks, the diaphragm piston 22 will move to its extreme up or down position depending if the inlet water is forcing it to its up stroke or downstroke. The direction of the water flow cannot change from one side of the piston 22 to the other, so the piston stops its up and down movement and water flow from the inlet line 20 to the outlet line 27 stops, since the water coming into either the upper or lower chamber is trapped and cannot flow through. This stopping of water can result in serious problems such as the shut off of drinking water to livestock. To prevent this shut off of water flow when the unit has stopped operation due to a failure, by pass valves have been supplied in the diaphragm piston. The valves are spring loaded so that during normal operation they remain closed but when the piston moves to its extreme position after a failure, however, these valves push against the pump body 11 and are forced open allowing water to pass through the piston and out the outlet.
More particularly, as seen in FIG. 1 a pair of by pass valves 42 and 43 are seen which are spring loaded closed. When the diaphragm piston 22 moves farther up from its position shown in FIG. 3, the top of valve 42 will strike the pump body 11 thereby forcing the valve 42 open and allowing water to flow through the piston 22 to fill both chambers 21 and 31 and out of chamber 31 past valve 23 which is now open. Contrarily, if the piston 22 moves farther down from its position shown in FIG. 1, then the bottom of valve 43 will strike the pump body 11 thereby forcing valve 43 open and allowing water to flow through the piston 22 to fill both chambers 21 and 31 and out of chamber 21 past valve 12 which is now open.
An additive pump 44 is disposed in an extension 45 of the pump body 11. The extension has an upper bore 46 which is coaxial with and one-half the cross sectional area of a lower bore 47. A piston rod 48 connects to the lower end of piston rod 32 and extends in a sliding and sealing relationship through the lower end of chamber 21. The piston rod 48 has an upper piston 49 in bore 46 and a lower piston 50 in bore 47 with the piston 49 having one-half the area of piston 50. A supply line 51 for additive fluid 51a connects to the bottom of extension 45 and a check valve 52 is located at the junction. When piston 50 moves up, check valve 52 is opened and when piston 50 moves down, check valve 52 closes. Piston 50 has a check valve 53 therethrough and when piston 50 moves upwardly, valve 53 closes, and when piston 50 moves downwardly, valve 53 opens.
As the pump piston rods 32 and 48 move up, a quantity of additive fluid is drawn through check valve 52 and into the bore 47 below piston 50 as shown in FIGS. 1 and 2. The quantity of fluid is equal to twice the amount of fluid which is desired to be injected into the quantity of water moving through the chambers 21 and 31 and out through line 27. An additive line 54 joins the bores 46 and 47 to the outlet line 27 and is connected to the extension 45 at the junction of the bores 46 and 47.
As the piston rods 32 and 48 are pushed down, check valve 52 closes and additive fluid is forced up through check valve 53 into the chamber between pistons 49 and 50. Piston 49 is one-half the area of piston 50 so that the chamber between the pistons 49 and 50 will only contain one-half the volume of additive being forced into it from the chamber below piston 50. The other one-half of this volume is forced out through line 54 to the outlet line 27. When the pump pistons 32 and 48 are pulled up again, check valve 53 closes, a quantity of additive fluid is drawn up into the chamber below the piston 50, and the remainder of the one-half volume between pistons 50 and 49 is forced out through line 54. By matching the volume of water required to move the diaphragm piston 22 with the volume of the additive fluid drawn up and inserted by the pistons 49 and 50, a given ratio of additive to water will be maintained.
In order to prime the additive pump, and referring to FIGS. 1 and 3, a small indentation 55 is formed in the wall of the lower bore 47 intermediate the ends thereof. As the piston 50 moves across the indentation 55 at the top of the stroke, additive liquid leaks around the seal and fills up the cavity below the piston thus priming the additive pump.
Although the above description relates to a presently preferred embodiment, numerous modifications can be made therein without departing from the spirit of the invention as defined in the following claims: | A proportioning pump for liquid additive metering having a housing with a diaphragm piston therein and inlet and outlet primary fluid lines to said housing for moving said diaphragm piston up and down. Additive pistons for pumping an additive liquid into said primary fluid with said additive pistons being moved by said diaphragm piston. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to a godet used for advancing, guiding, and heating an advancing synthetic filament yarn during the processing of the yarn. A godet of this general type is known, for example, from German Utility Model No. 1694542.
When heat treating an advancing yarn by means of a godet that advances the yarn, it is necessary that the rotating godet casing have over its entire surface a uniform surface temperature. To this end, the godet is conventionally heated by a radiation heater that is arranged in the interior of the godet and aligned substantially parallel to the godet casing.
Since the yarn loops several times about the godet casing along an axial contact length, it is also necessary that the godet casing have a substantially constant surface temperature along the entire contact length. However, in this connection, major heat losses are usually incurred in the end regions of the godet by thermal conduction or by circulating cooling air.
DE 195 32 036 C1 addresses this problem, and proposes that an adjustable cover be arranged between the radiation heater and the godet casing, so that in the godet casing heating zones are formed, which are more or less intensely heated depending on the adjustment of the cover. However, this arrangement has the considerable disadvantage of poor efficiency, since the cover shields from the godet casing the heat that is permanently generated by the radiation heater.
Likewise, the arrangement disclosed in U.S. Pat. No. 4,880,961 concerns a mode of operation of the radiation heater with poor efficiency, since the heat generated by the radiation heater must penetrate a wall of different thicknesses, so as to heat the godet casing.
Accordingly, it is an object of the invention to provide a godet of the above described type wherein the godet casing is heated by means of radiation heat such that the contact length of the godet has a substantially constant surface temperature.
A further object of the invention is to provide a godet, in which the energy generated by the heater results in heating the godet casing without significant losses.
SUMMARY OF THE INVENTION
The above and other objects and advantages of the present invention are achieved by the provision of a godet which comprises a godet support frame and a drive shaft rotatably mounted to the support frame. A tubular support is fixedly mounted to the support frame so as to coaxially surround the drive shaft, and a casing is fixed to the drive shaft so that the tubular outer wall of the casing is spaced outwardly from the tubular support. A radiation heater, which comprises at least one heating coil, is wound about the tubular support, and the heating coil exhibits different spacings between adjacent windings of the coil so as to provide non-uniform heating along the axial length of the casing.
The special advantage of the invention lies in the fact that the heat may be radiated as a function of the temperature distribution over the length of the godet casing. Thus, the radiation heater may generate a higher level of heat radiation in particular in the end regions of the godet casing. To achieve this result, the radiation heater is constructed with a heating coil which has over its length different spacings between adjacent windings. Thus, the zones that require in the godet casing a greater heat input based on heat conduction, exhibit a relatively small spacing between the windings of the heating coil.
The godet of the present invention permits the realization of any desired temperature profile along the contact length of the godet surface. In this connection, it is possible to predetermine with advantage the heat radiation both by the number of the windings of the heating coil and by the configuration of the spacings between adjacent windings.
A further advantage of the godet in accordance with the invention, resides in the fact that the godet casing is heated both by heat radiation and by convection. In this connection, use is made of the effect that by the rotation of the godet casing, an air current develops within the godet casing in the annular space formed between the godet casing and the radiation heater. This air current leads to a transfer of the energy from the heater to the godet casing by convection. It has been found that in such an arrangement the radiation heater is capable of operating in a range below the normal temperature range from 800 to 1,000° C.
In a further development of the invention, the heating coil of the radiation heater is embedded in a protective tube, which is spirally mounted to the tubular support. This avoids direct contact with the heating coil, for example, while changing a godet casing.
For purposes of embedding the heating coil, it is preferred to have an electric insulation sleeve arranged between the tabular support and the heating coil. This allows the heating coil to be mounted directly to the circumference of the tubular support and so as to be able to release its radiation heat undiminished in the direction toward the godet casing. This embodiment is preferably suitable for heating the godet casing to higher temperatures in a range of 300° C., since the portion of energy transferred by convection is especially large. The air current that is present between the godet casing and the heating coil has direct contact with the heating coil.
To increase the heat energy released by the radiation heater, it is advantageous to provide a reflector arranged between the tubular support and the radiation heater. Furthermore, this arrangement will also limit the heat energy that is released toward the interior. In particular for avoiding high storage temperatures, it is advantageous to position a heat insulation sleeve between the reflector and the support.
In accordance with a further preferred embodiment, an additional radiation heater is arranged on the tubular support opposite to the inner end wall of the godet casing. As a result thereof, an additional heat input is generated both into the outer peripheral region of the godet casing and into its end wall. This additional radiation heater thus inputs a heat energy into the region of the godet which is normally subjected to the greatest cooling.
The arrangement of the present invention has shown that a low surface temperature of the heating coil in a range from 500 to 800° C. will suffice to heat the godet casing to a temperature of about 250° C.
In one embodiment of the invention, a plurality of radiation heaters are provided which are disposed in a serial arrangement along the length of the tubular support. The heaters thus define separate heating zones, and the heaters are independently controllable. This embodiment can be used in particular for godets with a relatively long contact length from about 250 to 300 mm. The heat energy that is differently input into the zones of the godet is directly generated by the independently adjustable radiation heaters. The heating of the godet casing with several radiation heaters has also the advantage that it permits adjustment of a finely graduated surface temperature and enables a highly sensitive control of the surface temperature with fast recovery times. In this connection, the zones may have identical widths or different widths, with the windings in the heating coils being arranged equally or differently spaced apart from one another within a zone.
It is also desirable to provide a plurality of axially spaced apart annular ribs on the tubular support which are respectively disposed between adjacent heaters. The ribs are radially sized to provide an air gap of a few millimeters between the ribs and the godet casing. As a result, the respectively defined heating zones are heated as a function of the radiation heater associated thereto.
In the above embodiment, it is advantageous to mount a plurality of temperature sensors on the casing in radial alignment with respective ones of the heaters, and with each heater being controlled in a control circuit as a function of the measured temperature. This arrangement offers the possibility of being able to predetermine a temperature profile of the contact length by means of the control system.
The axial lengths of the heaters may be non-uniform. In this embodiment, the heating coils of the radiation heaters have different heating lengths, so that their specific load may be varied. In particular, it is possible to reach in the radiation heaters arranged in the opposite end regions of the godet, which are shorter than the heating coils of the radiation heaters in the center region of the godet, a specific load in a range of about 5 watts per square centimeter.
BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages, features, and applications of the invention will now be described in more detail with reference to the drawings, in which:
FIG. 1 is a sectioned side elevation view of a godet having a radiation heater in accordance with the present invention;
FIGS. 2-4 are views similar to FIG. 1 and illustrating additional embodiments of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 are each a schematic, axially sectioned view of a godet. Unless otherwise specified, the following description will apply to both figures. The godet is mounted on a stationary godet support frame 2, and it includes a drive shaft 3 which is mounted in cantilever fashion to the support frame by bearings 11, 13 so as to rotate about the axis of the shaft. A tubular support 4 is fixedly mounted to the support frame so as to be coaxial with and radially spaced from the drive shaft 3.
The godet further includes a casing 1 which includes a tubular outer wall and an end wall 25. In its center, the end wall 25 is provided with a collar 9 which is coaxial with the outer wall of the casing 1. Through end wall 25 and collar 9 a bore 10 extends, which flares out conically at the end of the collar. Inserted in formfitting manner into bore 10 is the free end of the drive shaft 3 which is in the form of a cone 8. A clamping element 5 secures the end wall 25 and the collar 9 to the cone 8 of the drive shaft 3. The drive shaft 3, with the casing 1 assembled thereto, is driven by a drive 12 which is mounted to the support frame 2.
The tubular support 4 is positioned between the projecting portion of the drive shaft 3 and the godet casing 1, and the godet casing surrounds the shaft in a cup shaped manner.
Both the projecting portion of drive shaft 3 and the collar 9 extend through the tubular support 4, and the free end of the tubular support is spaced from the end wall 25. Likewise, between godet casing 1 and the tubular support 4, an annular space 28 is formed, which accommodates a radiation heater 6. The radiation heater 6 comprises a heating coil 19, which spirals in a plurality of windings 26 around the tubular support 4. The heating coil 19 is connected to a connection 14 arranged on the godet support frame 2. Via connection 14, the radiation heater is supplied with electric power.
In the embodiment shown in FIG. 1, the heating coil 19 is inserted into a protective tube 7. Thus, the protective tube 7 is spirally wound around the tubular support 4 and attached thereto.
The winds of the protective tube 7 with heating coil 19 are wound around the support 4 in such a manner that the axial spacings between adjacent windings are smaller in the end regions of the support than the spacings of adjacent windings in the center region of the support. Between the protective tube 7 and the inside diameter of godet casing 1, a spacing is formed, which is typically sized from 6 to 15 mm. As a result of differently distributing the windings over the heating length of the radiation heater, it is accomplished that the regions of the godet casing which face the regions of the radiation heater with small spacings between windings 26, are heated to a greater extent. Thus, more heating energy is supplied to the regions which are subjected to greater heat losses.
To conduct heat radiation purposefully outward toward godet casing 1, as shown in the lower half of FIG. 1, it is advantageous to arrange a reflector 17 between the protective tube 7 and the tubular support 4. To prevent an excessively large amount of heating energy from reaching the drive shaft 3 and, thus, bearing 11, a layer of heat insulation 18 is arranged between the reflector 17 and the support 4.
In FIG. 2, the circumference of the tubular support 4 mounts an electrical insulation sleeve 20. The insulation sleeve contains in its circumference a spirally extending groove 31. The windings 26 of groove 31 are formed over the length of the support with different spacings between each other. In particular toward the inner end of the godet casing, the windings are arranged with a smaller spacing between one another than in the center region of the godet casing. Inserted into groove 31 is the heating coil 19. Thus, the heating coil 19 has no protective cover toward annular space 28 or godet casing 1. This arrangement permits a substantial increase in the portion of heat that is transferred by convection. The convection in annular space 28 is favored by an air current that is generated by rotating godet casing 1. As a result it is possible to compensate significantly for heat losses that occur at higher rotational speeds due to air currents developing in the peripheral region. Furthermore, energy of the radiation heater is input more efficiently into godet casing 1.
FIGS. 3 and 4 are each a schematic, axially sectioned view of a godet, whose casing is heated by a plurality of serially arranged radiation heaters.
The layout of the godet shown in FIG. 3 corresponds substantially to the layout of the godet shown in FIG. 1, so that the description of FIG. 1 is herewith incorporated by reference. In FIG. 3, the support 4 mounts, in serial arrangement, radiation heaters 6.1, 6.2, 6.3, 6.4, and 6.5. In this arrangement, each radiation heater 6.1-6.5 consists of a heating coil 19, which is embedded in a protective tube 7. The protective tube 7 winds helically around the tubular support 4. Each of the heating coils 19 is connected via connection 14 to an electric power supply unit. The support 4 mounts an annular rib 16 between adjacent radiation heaters 6.1, 6.2 and 6.2. 6.3 and 6.3, 6.4 and 6.4, 6.5. The ribs 16 are arranged in the shape of disks around the support 4, with an air gap 27 being formed between the outside diameter of the ribs 16 and the godet casing 1. The air gap 27 is substantially smaller than the spacing between radiation heaters 6 and godet casing 1 and amounts to only few millimeters.
In the arrangement shown in FIG. 3, the winds of protective tube 7 are equally spaced apart, so that each heating zone 29.1-29.5 that is formed between two adjacent ribs is uniformly heated over the length of heating coil 19. To realize zones which are heated with a higher heating energy on the godet casing, the lengths of the heating coils 19 of individual radiation heaters 6.1-6.5 are different. In the arrangement shown in FIG. 3, the radiation heaters 6.1 and 6.5 are each constructed with short heating coils. As a result, the specific load of the heating coil is increased, so that a larger amount of heating energy is released to the respective heating zones 29.1 and 29.5. The radiation heaters 6.1 and 6.5 are again located in zones, in which greater heat losses are incurred in the godet casing.
The radiation heaters 6.1-6.5 are mounted with their respective protective tubes 7 to the tubular support above a reflector 17 and a heat insulation sleeve 18.
In the end regions of the godet and in particular on end wall 25 of godet casing 1, a relatively great cooling occurs in conventional godets, since the end wall 25 is not heated or only inadequately heated, and since the end wall 25 represents a relatively large heat dissipation surface. To compensate for this cooling effect, the free end of the support 4 mounts an additional radiation heater 15, which is opposite to the end wall 25. Via this additional radiation heater 15, heating energy is supplied primarily to the end region of godet casing 1 and its end wall 25, so as to compensate for the energy dissipation in the aforesaid regions. As a result of this compensation, the region of the outer surface of godet casing 1, which has a substantially constant temperature on its contact length, is enlarged with respect to its length dimension, so that without increasing the constructional overall length of the godet, it is possible to enlarge the contact length on the godet.
In the godet shown in FIG. 4, the support 4 mounts again, in serial arrangement, a plurality of radiation heaters 6.1-6.4. In this embodiment, the heating coil 19 of each heater is embedded in an electrical insulation sleeve 20 that is provided with screw-thread type grooves 31. The electrical insulation sleeve 20 is mounted to the support 4. In like manner, as previously described with reference to FIG. 3, adjacent radiation heaters are separated from one another by annular ribs 16. Each of the thus-formed heating zones 29.1-29.4 is associated with a temperature sensor 21.1-21.4 accommodated in the godet casing. The temperature sensors 21.1-21.4 are connected to a data transmitter 24 arranged at the end of drive shaft 3. The data transmitter 24 transmits measured data between the rotating and the stationary structural components of the godet. The measured data are then supplied to a control device 22, which connects to a control system 30. The control system 30 assumes the control of the energy supply to the radiation heaters 6.1-6.4. Thus, it is possible to control each individual radiation heater as a function of the surface temperature of the godet casing, or to adjust a desired temperature profile along the contact length of godet casing 1.
Such a control has the advantage that material-specific properties, which influence the heat flow, do not affect the desired surface temperature of the godet casing.
In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation. | A godet for advancing, guiding, and heating an advancing synthetic filament yarn, which includes a rotating godet casing, which is cup shaped and is mounted over a stationary, tubular support. In the space formed between the godet casing and the support, a radiation heater is arranged on the circumference of the support, and the radiation heater is formed by a heating coil which is wound about the support with a plurality of windings. The coil has over its length different spacings between adjacent windings to provide non-uniform heating along the length of the casing and thereby compensate for the non-uniform cooling of the casing which naturally occurs. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to provisional patent application 61/307,238, filed Feb. 23, 2010.
FIELD OF THE DISCLOSURE
[0002] This disclosure relates in general to equipment and methods for cementing liner strings within a wellbore, and particularly to equipment that is utilized when the liner string serves as the drill string.
BACKGROUND
[0003] Oil and gas wells are conventionally drilled with drill pipe to a certain depth, then casing is run and cemented in the well. The operator may then drill the well to a greater depth with drill pipe and cement another string of casing. In this type of system, each string of casing extends to the surface wellhead assembly.
[0004] In some well completions, an operator may install a liner rather than an inner string of casing. The liner is made up of joints of pipe in the same manner as casing. Also, the liner is normally cemented into the well. However, the liner does not extend back to the wellhead assembly at the surface. Instead, it is secured by a liner hanger to the last string of casing just above the lower end of the casing. The operator may later install a tieback string of casing that extends from the wellhead downward into engagement with the liner hanger assembly.
[0005] When installing a liner, in most cases, the operator drills the well to the desired depth, retrieves the drill string, then assembles and lowers the liner into the well. A liner top packer may also be incorporated with the liner hanger. A cement shoe with a check valve will normally be secured to the lower end of the liner as the liner is made up. When the desired length of liner is reached, the operator attaches a liner hanger to the upper end of the liner, and attaches a running tool to the liner hanger. The operator then runs the liner into the wellbore on a string of drill pipe attached to the running tool. The operator sets the liner hanger and pumps cement through the drill pipe, down the liner and back up an annulus surrounding the liner. The cement shoe prevents backflow of cement back into the liner. The running tool may dispense a wiper retainer following the cement to wipe cement from the interior of the liner at the conclusion of the cement pumping. The operator then sets the liner top packer, if used, releases the running tool from the liner, and retrieves the drill pipe.
[0006] A variety of designs exist for liner hangers. Some may be set in response to mechanical movement or manipulation of the drill pipe, including rotation. Others may be set by dropping a ball or dart into the drill string, then applying fluid pressure to the interior of the string after the ball or dart lands on a seat in the running tool. The running tool may be attached to the liner hanger or body of the running tool by threads, shear elements, or by a hydraulically actuated arrangement.
[0007] In another method of installing a liner, the operator runs the liner while simultaneously drilling the wellbore. This method is similar to a related technology known as casing drilling. One technique employs a drill bit on the lower end of the liner. One option is to not retrieve the dell bit, rather cement it in place with the liner. If the well is to be drilled deeper, the drill bit would have to be a drillable type. This technique does not allow one to employ components that must be retrieved, which might include downhole steering tools, measuring while drilling instruments and retrievable drill bits.
[0008] Published application US 2009/0107,675, discloses a system for retrieving the bottom hole assembly by setting the liner hanger before cementing the liner. If the liner is at the total depth desired after retrieving the bottom hole assembly, the operator then runs a cementing assembly on a running tool back into engagement with the liner hanger. The cementing assembly includes a tieback assembly that stabs into sealing engagement with an upper portion of the liner string. A packer may also be included with the cementing assembly for sealing an annulus surrounding the liner. In addition, a cement retainer carried by the cementing assembly is pumped down to a lower end of the liner and latched after cementing. The cement retainer prevents backflow of cement.
SUMMARY
[0009] In the method disclosed herein, a valve assembly that is biased to a closed position is attached to a running tool assembly. A downward extending stinger of the running tool assembly extends through the valve assembly, holding the valve assembly in the open position. The running tool assembly and the valve assembly are placed into engagement with well conduit. The operator then performs one or more operations on the well conduit with the running tool assembly, including pumping a fluid through the stinger and the valve assembly while the valve assembly is in the open position. The operator then lifts the stinger from the valve assembly, causing the valve assembly to move to the closed position. The operator retrieves the running tool assembly from the conduit, leaving the valve assembly in engagement with the well conduit.
[0010] While in the closed position after the stinger is lifted, the valve assembly blocks upward flow of a fluid from below the valve assembly. In one embodiment, the valve assembly also blocks downward flow of a fluid from above the valve assembly.
[0011] In one method, the operation performed while the valve assembly is open includes pumping a cement slurry down the well conduit and back up an annulus surrounding the well conduit to cement the well conduit within a borehole. The operator may also pump a cement retainer from the running tool assembly down the well conduit into latching engagement with the well conduit near a bottom of the well conduit. The cement retainer prevents the cement slurry from flowing down the annulus and up the well conduit. After the cement retainer has latched, lifting the stinger closes the valve assembly. The closure of the valve assembly prevents the cement slurry from flowing down the annulus and up the well conduit in the event of failure of the cement retainer.
[0012] After lifting the stinger, the operator may circulate a cleaning liquid through the stinger while the valve assembly is in the closed position. The valve assembly blocks downward flow of the liquid past the valve assembly into the well conduit.
[0013] The operator may also mount a tieback assembly to the running tool assembly and secure the valve assembly to the tieback assembly. When lowering the running tool assembly into the well, the operator stabs the tieback assembly sealingly into the well conduit. Normally, the tieback assembly includes a packer. After cementing, the operator sets the packer above the cement slurry and within the annulus surrounding the well conduit.
[0014] In one embodiment, the valve assembly includes a tubular housing having an axis. A pair of valve seats is mounted within the housing in axial alignment with each other. A flapper valve element is secured bra hinge to each of the seats for pivotal movement between open and closed positions. Each of the flapper valve elements is biased to the closed position in contact with one of the seats. One of the valve elements pivots in a first direction when moving from the closed to the open position. The other of the valve elements pivots in a second direction when moving from the closed position, such that when, both are in the closed position, fluid flow through the housing is prevented in both directions.
[0015] Preferably, an annular seal interface is located axially between the valve elements for sealingly engaging a tubular stinger inserted through the seats while the valve elements are in the open position. The seats may be on opposite ends of a tubular body having an outer diameter scaled to an inner diameter of the housing. The annular seal interface may be located in a bore of the body axially between the seats.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIGS. 1A-1C comprise a half-sectional view of a liner string having a bottom hole assembly installed for drilling with the liner string.
[0017] FIGS. 2A-2C comprise a half-sectional view of a packer and cementing assembly for installation with the liner string after the bottom hole assembly is retrieved.
[0018] FIGS. 3A-3B comprise a half-sectional view of a running tool assembly for running the packer and cementing assembly of FIGS. 2A-2C .
[0019] FIGS. 4A-4F comprise a half-sectional view of the running tool assembly of FIGS. 3A-3B positioned within the packer and cementing assembly of FIGS. 2A-2C and the packer and cementing assembly inserted into an upper end of the liner string.
[0020] FIG. 5 is a half-sectional view of the valve assembly carried by the running tool assembly in FIGS. 3A-3B and 4 A- 4 F.
DETAILED DESCRIPTION
[0021] Referring to FIGS. 1A and 1C , a string of casing 11 has been previously installed and cemented in the wellbore. A liner string 13 extends down from casing string 11 to the total depth of the wellbore, but has not yet been cemented in place. The term “liner string” refers to a string of well pipe that does not extend all the way up to the wellhead; rather it will eventually be cemented in the wellbore with its upper end a short distance above the lower end of casing string 13 . The terms “casing” and “liner” may be used interchangeably. In this embodiment, liner string 13 will normally have been deployed by drilling the wellbore at the same time the liner string 13 is being lowered into the well.
[0022] Referring to FIG. 1C , a cementing retainer profile 17 , such as an annular recess, is also located near the lower end of casing string 13 . During liner drilling, a bottom hole assembly (BHA) 19 extends from the lower end of liner string 13 . BHA 19 is shown in dotted lines because it will be retrieved in this example before the cementing occurs. BHA 19 includes a drill bit 21 and normally additional equipment, such as an underreamer and optionally surveying instruments and directional drilling equipment.
[0023] Liner string 13 also includes a torque or profile sub 23 ( FIG. 1B ), which is near the upper end of liner string 13 in this embodiment. Torque sub 23 has an internal profile 25 , such as vertical splines. A liner running tool 27 releasably secures an upper section of a work string, such as drill pipe 26 ( FIG. 1A ), to torque sub 23 of liner string 13 for transmitting torque to liner string 13 and supporting the weight of liner string 13 . A lower drill pipe section 28 ( FIG. 1C ) extends downward from torque sub 23 through liner string 13 and is secured to BHA 19 . Rotating drill pipe 26 ( FIG. 1A ) by a drilling rig (not shown) will cause lower drill pipe section 28 to rotate BHA 19 , applying drilling torque to drill bit 21 . Torque sub 23 also causes liner running tool 27 to rotate, which in turn rotates torque sub 23 because of its engagement with profile 25 . This results in the entire liner string 13 and BHA 19 rotating. Drilling fluid is pumped down upper drill pipe string 26 , lower drill pipe string 28 and out bit 21 of BHA 19 . Published application US 2009/0107675 describes more details of the liner drilling system illustrated in FIGS. 1A-1C . Other systems for drilling with liner string 13 are feasible, including having the torque sub located near the lower end of liner string 13 rather than at the upper end as shown in FIG. 1B .
[0024] Referring to FIG. 1B , liner string 13 also includes a lower polished bore receptacle 29 located above torque sub 23 . Lower polished bore receptacle 29 is a cylindrical member having a smooth bore for sealing purposes. A liner hanger 31 ( FIG. 1A ) mounts to the upper end of lower polished bore receptacle 29 . Liner hanger 31 will be placed in a set position before removing drill pipe strings 26 , 28 , running tool 27 and BHA 19 . Liner hanger 31 may be a type that can be reset in order to retrieve BHA 19 for repair or replacement. If resettable, the operator can run BHA 19 back, re-engage running tool 27 with torque sub 23 and release liner hanger 31 to continue drilling. Alternately, liner hanger 31 may be a type that is set only once and remains set. Liner hanger 31 has slips 33 that grip the inner diameter of casing string 11 and support the weight of liner string 13 when set. At the completion of drilling, liner hanger 31 will be set near but above the lower end of casing string 11 .
[0025] Once the well has been drilled to total depth and BHA 19 and running tool 27 are retrieved, liner string 13 will be in condition for cementing. Referring to FIGS. 2A-2C , a packer and cementing assembly 35 will be lowered into engagement with liner hanger 31 , upper polished bore receptacle 29 and the upper portion of torque sub 23 . FIGS. 2A-2C illustrate packer and cementing assembly 35 as it would appear prior to lowering into casing 11 . Packer and cementing assembly 35 includes on its lower end a tieback seal nipple 37 , as shown in FIG. 2 C. Tieback seal nipple 37 is a tubular member having seals 41 located on its outer diameter. Seals 41 are adapted to sealingly engage the inner diameter of lower polished bore receptacle 29 ( FIG. 1B ). Tieback seal nipple 37 has an optional latch 39 on its lower end with gripping members that will engage a grooved profile in the upper end of torque sub 23 , as shown in FIG. 4D .
[0026] Referring to FIG. 2B , a valve assembly 43 connects to the upper end of tieback seal nipple 37 in this example. Valve assembly 43 comprises a mechanism that has an open position and a closed position. In the closed position, valve assembly 43 seals against pressure from below and optionally against pressure from above. In the open position, valve assembly 43 may allow fluid to flow through in both directions. In this example, valve assembly 43 comprises an upper flapper valve element 45 and a lower flapper valve element 47 , each of which will pivot between an open position shown in FIG. 2B and a closed position, shown by dotted lines in FIG. 5 . Referring to FIG. 5 , each flapper element 45 and 47 is connected by a hinge 49 to a valve seat 50 . Although the valve seats 50 could be separate elements, in this example, one valve seat 50 comprises an upper end portion of a tubular central body 51 . The other valve seat 50 comprises a lower end portion of body 51 . Also, in this example, the upper seat 50 faces upward and the lower seat 50 faces downward. When in the closed position, as shown by the dotted lines, upper flapper 45 will seal against the upward facing seat 50 , and lower flapper 47 will seal against the downward facing seat 50 . When moving from the closed to the open position, one of the flappers 45 will pivot in one direction and the other in an opposite direction. For example, upper flapper 45 pivots upward when opening and lower flapper 47 pivots downward while opening. Upper and lower flappers 45 and 47 are biased by conventional springs (not shown) to the closed position.
[0027] The positions of flappers 45 , 47 may be reversed; flapper 47 may be biased to seal pressure from above and flapper 45 from below. In that instance flapper 47 would pivot upward to open and flapper 45 would pivot downward to open. Hinges 49 are shown to be on the same side of central body 51 , which is the left side as shown in FIG. 5 . Alternately, hinges 49 could be on different sides of central body 51 .
[0028] Central body 51 is secured within the bore of a tubular housing 53 with its outer diameter in sealing engagement with the bore of tubular housing 53 . Central body 51 preferably is rigidly attached to tubular housing 53 and may be secured within tubular housing 53 in various manners, including retainer rings, press-fitting or welding. Flappers 45 and 47 can be held in the open position by a central tubular member that will be subsequently explained. The bore of central body 51 has a seal interface for sealing against the tubular member. In this embodiment, the seal interface comprises seals 63 mounted in annular grooves in the bore of central body 51 . Valve assembly 43 is formed of a drillable material, such as aluminium. Rather than flapper valve elements, another assembly that would work for the same purpose would include upper and lower ball valves. Central body 51 includes an upper adapter 59 on its upper end and a lower adapter 61 on its lower end. Referring back to FIG. 2B , adapters 59 , 61 have threads that attach housing 53 into packer and cementing assembly 35 ( FIG. 2A ).
[0029] Still referring to FIG. 2A , a liner top packer 67 secures to the upper end of top adapter 59 . Liner top packer 67 may be a conventional packer for sealing between liner string 13 and the inner diameter of casing 11 ( FIG. 1A ). In this example, liner top packer 67 is set by weight although it could be rotationally or hydraulically set. Liner top packer 67 has a body 69 that is tubular and has a conical upper end 71 . Elastomeric packer elements 73 are located around body 69 . A set of slips 75 is positioned on conical upper end 71 . An inner tubular body of liner top packer 67 has an interior set of left-hand threads 78 , but other attachment devices besides left-had threads are feasible. A setting sleeve 76 surrounds the inner tubular body and engages the upper end of slips 75 . Packer 67 is shown in the unset position in FIG. 2A . To set, a downward force on setting sleeve 76 will cause slips 75 to be expanded over conical surface 71 and will also deform packer elements 73 radially outward. Slips 75 will engage the inner diameter of casing 11 ( FIG. 1A ) to hold liner top packer 67 in the set position.
[0030] An optional upper polished bore receptacle 77 may be mounted to the upper end of setting sleeve 76 . Upper polished bore receptacle 77 is utilized for sealing purposes in case of problems in sealing tieback seal nipple 37 ( FIG. 2C ) to lower polished bore receptacle 29 ( FIG. 1A ) if another packer is required for sealing to casing string 11 . Prior to cementing, packer and liner top assembly 35 of FIGS. 2A-2C will be lowered into engagement with torque sub 13 , lower polished bore receptacle 29 and liner hanger 31 , as shown in FIGS. 1A and 1B . Packer and liner top assembly 35 will remain in the wellbore after cementing.
[0031] FIGS. 3A and 3B illustrate a running tool assembly 79 , most of which will be retrieved after cementing. Running tool assembly 79 includes an adapter 81 at the upper end for securing it to a work string such as a string of drill pipe. Running tool assembly 79 includes a packer setting tool 83 , which secures to the lower end of adapter 81 . Packer setting tool 83 is a type utilized for setting packer 67 ( FIG. 2A ). In this example, packer setting tool 83 is a mechanical type tool that sets in response to rotation and weight imposed by the running string. Alternately, it could be a hydraulically actuated tool. Packer setting tool 83 has a set of spring-biased dogs 85 that are biased radially outward. When running tool assembly 79 is inserted into packer and cementing assembly 35 , dogs 85 will be located within upper polished bore receptacle 77 and urged outward against the sidewall of receptacle 77 . In this initial position, dogs 85 will not transmit any downward weight. When engaging an upward facing shoulder, such as the rim of upper polished bore receptacle 77 , dogs 85 will transmit a downward force. Packer setting tool 83 may have a clutch mechanism 87 of a type conventionally utilized for setting tools for liner top packers. Clutch mechanism 87 transmits rotation when weight is imposed on it. Packer setting tool 83 has a left-hand threaded connector 89 on its lower end. Threaded connector 89 will be secured to left-hand threads 78 ( FIG. 2A ) of the inner tubular body of liner top packer 67 while being assembled at the surface. The engagement of threaded connector 89 with threads 78 connects packer and cementing assembly 35 of FIGS. 2A-2C to running tool assembly 79 of FIGS. 3A and 3B .
[0032] Running tool assembly 79 includes a stinger 91 that extends downward from threaded connector 89 . Stinger 91 is a tubular member that extends through valve assembly 43 and holds flapper elements 45 and 47 in the open position. Seals 63 ( FIG. 5 ) in body 51 seal against stinger 91 . Alternately, seals 63 could be located on stinger 91 .
[0033] Stinger 91 has a cementing retainer or plug 93 releasably connected to its lower end. In this embodiment, cement retainer 93 is a latching type. As shown in FIG. 3B , cementing retainer 93 has an inner body 95 that may be rigid and formed of a drillable material. An axial passage 96 extends through inner body 95 for the passage of fluid. An outer sleeve 97 is formed of elastomeric material and has circumferentially extending ribs 99 . Ribs 99 are adapted to form a seal in liner string 13 . Cement retainer 93 has an adapter 101 on its upper end that releasably secures cement retainer 93 to the lower end of stinger 91 with shear pins. Adapter 101 has an internal seat 103 that is adapted to receive a sealing object pumped down, such as a dart 107 ( FIG. 4D ). Dart 107 is a conventional pump-down member that has seals and once in sealing engagement with adapter 101 , the combination will form a seal in liner string 13 . In this embodiment, a latch 105 extends around body 95 for engaging profile 17 ( FIG. 1C ). Alternatively, cementing retainer 93 could be a non-latching type.
[0034] In operation, the well will be drilled, preferably utilizing liner string 13 as the drill string. Once at total depth, liner hanger 31 ( FIG. 1A ) will be set in casing string 11 to support the weight of liner string 13 . Then the operator retrieves liner running tool 27 , drill pipe sections 26 , 28 and bottom hole assembly 19 ( FIG. 1C ).
[0035] The operator then assembles running tool assembly 79 of FIGS. 3A and 3B in packer and cementing assembly 35 of FIGS. 2A-2C . When doing so, in this example, the operator will secure threaded connector 89 to threads 78 by left-hand rotation. Stinger 91 will pass through valve assembly 43 , pushing and retaining flappers 45 , 47 in the open position. Seals 63 ( FIG. 5 ) seal around stinger 91 . Tieback seal nipple 37 will be spaced such that when lowered into casing string 11 , it will be substantially located within lower tieback receptacle 29 . Cement retainer 93 ( FIG. 3B ) will be in sealing engagement with tieback seal nipple 37 . Dart 107 will not be in position at this time. The operator secures adapter 81 to a work string, such as drill pipe 26 ( FIG. 4A ), and lowers the entire assembly.
[0036] Referring to FIG. 4F , latch 39 on the lower end of tieback seal nipple 37 will enter lower polished bore receptacle 29 and latch into an annular grooved profile formed in the upper end of torque sub 23 . As shown in FIG. 4D , cement retainer 93 will be located within liner hanger 31 , and valve assembly 43 will be above, as shown in FIG. 4C . Liner top packer 67 will be located within casing string 11 above liner hanger 31 as shown in FIGS. 4B-4D .
[0037] The operator at that point preferably releases the engagement of running tool assembly 79 ( FIG. 4D ) from packer and cementing assembly 35 ( FIG. 4B ). In this embodiment, the operator disengages by rotating drill pipe 26 to the right, which will unscrew threaded connector 89 from internal threads 78 ( FIG. 4B ). Once released, the operator will pull running tool assembly 79 upward a short distance with drill pipe 26 . This will cause the running tool assembly 79 to move upward relative to the packer and cementing assembly 35 , indicating to the operator that running tool assembly 79 is released from packer and cementing assembly 35 . The operator will then set back down without setting packer 67 .
[0038] The operator then is free to pump cement down drill pipe 26 and the assembly shown in FIGS. 4A-4F . The cement will flow through cement retainer 93 ( FIG. 4D ), the torque sub 23 ( FIG. 4F ) and out the bottom of liner string 13 . When the desired quantity of cement has been dispensed, the operator then drops dart 107 ( FIG. 4D ) down drill pipe 26 . Dart 107 lands in sealing engagement with adapter 101 of cement retainer 93 . Applying fluid pressure at the surface will cause the shear pin between adapter 101 and stinger 91 to release. Cement retainer 93 and dart 107 move down in unison into engagement with profile 17 ( FIG. 1C ). Once in engagement, cement retainer 93 and dart 107 form a seal in liner string 13 and are prevented from moving upward by the latching engagement. The cement in the annulus surrounding liner string 13 will be prevented from flowing back up within liner string 13 by cement retainer 93 and dart 107 .
[0039] The operator will then set liner top packer 67 ( FIG. 4B ) by first pulling upward a distance sufficient for dogs 85 ( FIG. 4A ) to move above the upper end of upper polished bore receptacle 77 . Dogs 85 will then spring outward past the outer diameter of upper polished bore receptacle 77 . The amount of this upward movement is not enough to cause stinger 91 to move above valve assembly 43 ( FIG. 4C ), thus flappers 45 , 47 remain open. The operator then lowers drill string 26 and running tool assembly 79 relative to packer and cementing assembly 35 . Dogs 85 will contact the upper end of upper polished bore receptacle 77 . The operator slacks off weight, which transmits through upper polished bore receptacle 77 to setting sleeve 76 . Setting sleeve 76 will move downward relative to packer body 69 , which causes liner top packer 67 to set. Its slips 75 will grip the inner diameter of casing 11 . Packer elements 73 will seal against the inner diameter of casing 11 .
[0040] The operator then will pull drill string 26 upward again, but a distance sufficient to place the lower end of stinger 91 above valve assembly 43 . This upward movement causes stinger 91 , which previously was holding flappers 45 and 47 ( FIG. 4C ) in the open position, to move above flappers 45 and 47 . Flappers 45 and 47 will then spring to the closed position shown by the dotted lines in FIG. 5 . This closed position prevents any upward flow of fluid in the event of cement in the annulus leaking past cement retainer 93 ( FIG. 4D ). The closure of flappers 45 , 47 also prevents any downward flow of fluid below valve assembly 43 . The barrier created will allow the operator to circulate a cleaning fluid, such as water, downward and out the lower end of stinger 91 ( FIG. 4D ). The cleaning fluid circulates back up the annulus surrounding drill pipe 26 . Alternately, the operator could circulate the cleaning fluid down the annulus in casing 11 surrounding drill pipe 26 and back up stinger 91 . This fluid flow will clean liner top packer 67 and upper polished bore receptacle 77 of cement and debris. If cleaning is not required, valve element 43 could have a single flapper valve element, rather than two. The single flapper valve element would block upward flowing fluid in case cement retainer 93 leaks, but would not block downward flowing fluid.
[0041] After cleaning, the operator is free to pull up running tool assembly 79 , except for cement retainer 93 , which remains latched at the lower end of liner sting 13 . Once running tool assembly 79 has been retrieved, and when the operator wishes to complete the well, he will lower a string with a drill bit into the casing 11 . The drill bit is employed to drill through the valve assembly 43 , which is made of easily drillable components. This disintegration of valve assembly 43 thus opens the cemented liner string 13 down to cement retainer 93 ( FIG. 3B ). If desired, the operator may wish to drill out the cement retainer 93 , which may also be formed of drillable materials. The operator then may complete the well by in a conventional manner, such as by running tubing and perforating.
[0042] While only one embodiment has been shown, it should be apparent to those skilled in the art that various changes and modifications may be made. | A method of cementing a liner in a well includes mounting a valve assembly that is biased in a closed position to a running tool assembly. The running tool assembly has a stinger inserted through the valve assembly, retaining the valve assembly in an open position. The stinger has a cement retainer releasably mounted to it. After lowering the running tool assembly into engagement with the liner string, the operator pumps a cement slurry through the stinger and the valve assembly. The operator then pumps the cement retainer down the liner string into latching engagement with a lower portion of the liner string. Afterward, the operator lifts the stinger from the valve assembly, causing the valve assembly to move to the closed position. The valve assembly blocks upward flow of fluid from the well conduit through the valve assembly in the event of leakage of the cement retainer. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional of U.S. patent application Ser. No. 11/060,895, filed Feb. 18, 2005, which is incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
The present invention relates, in general, to the field of rotating data storage media. More particularly, the present invention relates to a system and method for the production level screening of low flying magnetic heads in the manufacture of disk drive head disk assemblies (HDAs).
A partially cut-away, isometric illustration of a typical prior art disk drive HDA 10 is shown in FIG. 1 . The HDA 10 includes a number of disks 12 which are rotated about a spindle 14 by means of a motor (not shown). An actuator motor 16 positions an arm 18 with respect to data tracks on the surfaces of the disks 12 . The actuator arm, in turn, positions a suspension 20 and head 22 which flies adjacent to the rotating surfaces of the disks 12 .
A disk drive read/write head generally comprises a read/write transducer and a slider that includes an air bearing surface (ABS). The ABS allows the slider to “fly” adjacent the surface of a rotating disk due to the development of an air bearing between the disk surface and the ABS. The slider is generally bonded to a thin metal arm, or suspension, that holds the head in position above or beneath the rotating disks. Typically, the combination of a head and suspension is called a head gimbal assembly (HGA) and multiple HGAs may be stacked together to form a head stack assembly (HSA). Functionally, the arms and heads of the HSA are positioned with respect to the respective disk surfaces during operation by means of an actuator or servo mechanism.
As mentioned previously, during normal operation, the read/write head is separated from the disk surface as it spins by a thin air bearing. The suspension serves to apply a force in a direction opposite to the pressure generated by the air bearing to maintain an equilibrium condition in which the transducer is separated from the disk surface by a small controlled spacing, to enable the reading and writing of data. If the desired equilibrium condition is disturbed, for example by excessive shock or vibration, or if the equilibrium condition is never established, for example due to component manufacturing variances, the head can crash into the disk surface. Not only can this damage the disk surface at that location, but debris from the crash site can cause further problems throughout the HDA.
As the areal density of disk drives increases, heads are required to fly lower and lower to the disk surface in order to read and write data. With current technology, this height can be below 0.5 micro-inches. In actual head production, there is often a variation in the fly heights of the heads in a given product due to process specific tolerances. Heretofore, most approaches have attempted to control and reduce the flying height variations (sigma) on a given lot, and from lot to lot. The variations may also be reduced by improved suspension design (e.g. low stiffness), the ABS design, and other manufacturing process controls that reduce fly height sensitivity to process specific tolerances.
To account for fly height variation, the ABS must be designed to fly slightly higher than would otherwise be desirable. The fly height resulting from an ABS design is typically determined by computer modeling and simulation based on the well-known Reynold's Equation. However such computer simulation results must be confirmed and calibrated by experimental testing of fly height.
In this regard, certain patents illustrating the current state of the art in making and using calibration disks to enable the testing of the flying heights of certain heads in a test environment include: U.S. Pat. No. 5,528,922 issued Jun. 25, 1996 for: “Method of Making Disk Bumps with Laser Pulses for Calibrating PZT Sliders”; U.S. Pat. No. 6,408,677 issued Jun. 25, 2002 for: “Calibration Disk Having Discrete Bands of Composite Roughness”; and U.S. Pat. No. 6,164,118 issued Dec. 26, 2000 for: “Calibration Disk Having Discrete Bands of Calibration Zones”. It should be noted that the subject matter of these specific patents is directed to testing (e.g., glide head calibration) in a test environment and not a production level screening technique as disclosed herein.
SUMMARY OF THE INVENTION
Disclosed herein is a method for manufacturing a group of head gimbal assemblies. The method comprises the acts of providing a test disk having a plurality of bumps extending from at least one surface thereof, rotating the test disk to fly a head of a head gimbal assembly selected from the group adjacent the at least one surface of the test disk, sensing an interaction of the head with one or more of the plurality of bumps and screening out the head gimbal assembly selected from the group in response to the sensing of the interaction. Further provided herein is a system for implementing the aforedescribed method and a disk drive head disk assembly including at least one of a group of head gimbal assemblies screened by the method.
BRIEF DESCRIPTION OF THE DRAWINGS
The aforementioned and other features and objects of the present invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of exemplary embodiments taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a isometric illustration of a partially cut-away, representative prior art disk drive head disk assembly (HDA);
FIG. 2A is a simplified representation of a disk drive read/write head slider assembly flying above the surface of a rotating disk as affixed to an associated suspension and test arm having, for example, an acoustic emission (AE) sensor associated therewith;
FIG. 2B is an enlarged view of a read/write head slider assembly as shown in the preceding figure illustrative of the head flying below the height of predetermined height laser bumps associated with a DET test disk media and which will generate an AE signal upon contact between the head and the bump;
FIGS. 3A , 3 B and 3 C are graphical representations of exemplary fly height distributions at mean fly heights (FH) of substantially 10.0 nm (0.40 micro-inches), 8.0 nm (0.32 micro-inches) and 6.5 nm (0.23 micro-inches) respectively illustrating fly height and glide avalanche (GA) ranges at population frequencies of between 0.0 and 2000 wherein the low flying heads are seen to touch as the mean fly height is lowered;
FIG. 4 is a simplified production flow chart in accordance with the present invention illustrating the use of an on-line AE tester to enable the screening of low flying heads prior to dynamic electrical test (DET);
FIG. 5 is a graphical illustration of an exemplary minimum head fly height cut off (in micro inches) versus bump height (in Angstroms) assuming negligible air cushion effects in a representative implementation of the system and method of the present invention; and
FIG. 6 is a functional block diagram of an integrated head tester system in accordance with the present invention illustrative of key components for DET measurements and screening of low flying heads utilizing, for example, AE signal detection.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
An embodiment of the present invention, as disclosed herein, advantageously provides a production technique that serves to identify and remove the extreme low flying heads (e.g. the lower approximately 2.0%-5.0% of the distribution) utilizing, for example, acoustic emission (AE) sensors and laser bumps on test disks. Removal of the lower flying devices in the fly height distribution effectively serves to reduce the incidence of head/disk contact, and hence, to improve the overall reliability of the drives ultimately produced.
A system and method of an embodiment of the present invention further provides for production line monitoring of head fly height to enable the screening out of very low flying heads which may cause HDA reliability problems. The reliability of the resultant disk drives may be significantly improved by reducing the head/disk interface problems caused by low flying heads. Such problems may include, for example, lubricant degradation, read/write errors, debris generation and the like.
Implementation of a system and method of an embodiment of the present invention may be effectuated by the inclusion of, for example, an acoustic emission sensor and associated amplifier into existing industry test equipment and the provision of suitable media for dynamic electrical testing (DET) with added laser bumps at one or more of the inner diameter (ID), middle diameter (MD) and/or outer diameter (OD) of the disk. The result is a test environment which may be implemented in a manner compatible with existing glide height testing for disks.
With reference additionally now to FIG. 2A , a simplified representation of a system 100 comprising a disk drive read/write head slider assembly 106 flying above the surface 104 of a rotating disk 102 is shown. The read/write head slider assembly 106 is affixed to an associated suspension 108 and test arm 110 having, for example, an acoustic emission (AE) sensor 112 associated therewith.
In conventional applications for use with glide avalanche (GA) disks, a sensor is mounted on the glide on the glide head itself. As illustrated herein, the AE sensor 112 is mounted remotely from the head and may be mounted directly on the test arm adjoining the attachment of the suspension. In a particular implementation of the system and method of the present invention, low flyers may be detected in accordance with the technique disclosed herein using, inter alia, a contact start stop (CSS) tester such as the Olympus tester produced by the Center for Tribology, Inc. (CETR), Campbell, Calif.
With reference additionally now to FIG. 2B , an enlarged view of a read/write head slider assembly 106 as shown in the preceding figure is depicted illustrative of the head slider assembly 106 flying below the height of predetermined height laser bumps 114 formed on the surface 104 of a DET test disk 102 media. Like structure to that previously described with respect to FIG. 2A is like numbered and the foregoing description applies to this structure and/or these components. In operation, contact between the head slider assembly 106 and one or more of the bumps 114 will serve to generate an AE signal by means of sensor 112 ( FIG. 2A ) which can be monitored to enable screening of low flyers in accordance with a system and method of an embodiment of the present invention as disclosed herein.
With reference additionally now to FIGS. 3A , 3 B and 3 C, graphical representations of exemplary fly height distributions at mean fly heights (FH) of substantially 10.0 nm (0.40 micro-inches; FIG. 3A ), 8.0 nm (0.32 micro-inches; FIG. 3B ) and 6.5 nm (0.23 micro-inches FIG. 3C ) are shown. These figures illustrate fly height and glide avalanche (GA) ranges at population frequencies of between 0.0 and 2000 wherein the low flying heads are seen to touch as the mean fly height is lowered.
The range of mean fly height applicable to a specific embodiment of the present invention disclosed herein may be from 6.4 nm (0.25 micro-inches) to 12.7 nm (0.50 micro-inches). A possible cut-off range for low flyers would then be, for example, from mean fly height—1.5 sigma (6.7% of normal distribution) to mean fly height—3 sigma (0.13% of normal distribution). In accordance with the Case 2 scenario of FIG. 3B in particular, a mean fly height of 8.0 nm (0.32 micro-inches) is illustrated with a sigma of 1.0 nm. With a cut-off threshold for low flyers set at 8.0 nm—2 sigma, this equates to 6.0 nm (0.24 micro-inches). As such, this would remove approximately 2.3% of the population of heads (given a normal distribution) and improve the overall head/disk reliability.
With reference additionally now to FIG. 4 , a simplified production process 300 flow chart in accordance with an embodiment of the present invention is shown illustrating the use of an on-line AE tester to enable the screening of low flying heads prior to dynamic electrical test (DET). The process 300 includes the introduction of head gimbal assemblies (HGAs) to the DET test stand at step 302 , and introduction of bump disk samples to the DET test stand at step 306 , for AE testing at step 304 . The HGAs passing through the AE tester step 304 are then subjected to a DET test at step 308 , following which they are further assembled into head stack assemblies (HSAs) at step 310 and then into head disk assemblies (HDAs) at step 312 .
In other embodiments (not shown), the AE tester step 304 is performed after the head gimbal assemblies are assembled into head stack assemblies at 310 (i.e., the AE testing using the disk bumps may be performed upon one or more of the disks in a head stack rather than on each head gimbal assembly). In other words, a “group” of HGAs may be tested individually prior to assembly into an HSA or a “group” of HGAs may be assembled into an HAS and then, one or more of the HGAs in the HSA may be tested with an AE tester at step 304 .
In the production of HGAs, the AE test step 304 and DET test step 308 may conveniently be combined (as indicated by the dashed-line box but it should be noted that the DET test step 308 is not required to practice the invention) and accomplished on the same DET test stand in accordance with the representative embodiment of the present invention shown, inter alia, to reduce overall cycle time. Further, the method may be implemented utilizing certain electrical testers available from Guzik Technical Enterprises, Mountain View, Calif., with an AE sensor (e.g. sensor 112 of FIG. 2A ) to detect head/disk interactions.
With reference additionally now to FIG. 5 , a graphical illustration of an exemplary minimum head fly height cut off (in micro inches) versus bump height (in Angstroms) is shown in a representative implementation of the system and method of the present invention. In this example, the bumps are assumed to have negligible effect on fly height except at the location of each bump.
A disk incorporating specific bumps (whether formed by laser or otherwise) for use in screening low flyers may include bumps or other protrusions similar to the laser textured bumps on the disk landing zone. The height of the bumps, the bump density (i.e., the number of bumps on the disk surface per unit area), and/or their radial and circumferential spacing may be optimized for screening out low flyers. For example, assuming negligible bump effect on fly height as shown, the height of the bumps will be close to the actual flying height of sliders that fly just high enough to not be rejected (i.e. screened out) as flying too low. In an embodiment of the present invention this may correlate with the negative three sigma (3σ) threshold in a fly height distribution of a group of manufactured sliders built into HGAs. In the exemplary case of a 0.24 micro-inch flying height, the bump height would then be close to 6.0 nm or possibly higher. However, the AE signal strength depends on bump characteristics including bump height, bump density on the disk, bump height relative to fly height, and/or other bump characteristics. Higher bump density can be used and a bump height greater then 6.0 nm may be needed in order to compensate for the effect of the bumps on fly height as the heads will tend to fly higher than normal. The actual bump height is a matter of design choice and may be determined by the calibration of the tester with a range of heads with known fly heights and corresponding bump test disks with a range of bump heights.
With reference additionally now to FIG. 6 , a functional block diagram of an integrated head tester system 500 in accordance with an embodiment of the present invention is shown which is illustrative of key components for DET measurements and screening of low flying heads utilizing, for example, AE signal detection. As previously described with respect to FIG. 2A , a read/write head slider assembly 106 may be affixed to an associated suspension 108 and test arm 110 having, for example, an acoustic emission (AE) sensor 112 associated therewith. The head slider assembly 106 flies over the surface 104 of test disks which are used to screen out low flyers. These disks have incorporated special laser bump heights at the inner diameter (ID), middle diameter (MD) and outer diameter (OD). These bumps may also conveniently be provided on DET test disks such that DET testing will immediately follow this test on the same disk as illustrated at step 308 in the process 300 of FIG. 4 . Heads that fly below the minimum fly height specification will physically touch the bumps and cause a higher AE signal from the sensor 112 . This would result in the rejection of the head before or concurrent with DET testing.
As shown, output from the sensor 112 may be applied through an AE preamplifier 502 to an AE analyzer 504 . In addition, output from the read/write head itself may be supplied to a read/write (R/W) signal preamplifier 506 to a corresponding R/W signal analyzer 508 . Output from the AE analyzer 504 and R/W signal analyzer 508 may be furnished to a computer 510 which operatively enables a spin stand controller 512 . The spin stand controller 512 provides control signals to a spin stand 514 , which serves to rotate the test disk in a controlled manner, and may also provide control signals to a course servo positioner 516 and a micropositioner 518 which control the positioning of the read/write head radially over the disk surface 104 .
In operation, the laser bump height, diameter and spacing are optimized to produce a higher AE signal from the sensor 112 if the head flies below a certain minimum fly height (e.g. 0.25 micro-inches) as shown in the graph of FIG. 5 . As may be required, a special batch of test heads may be made to check the AE sensitivity to fly height. In representative applications, the heads can fly in the range of 0.40 to 0.20 micro-inches. As an example, a head may be selected that flies at 0.25 micro-inches and a corresponding bump height and spacing can then also be selected that will result in a strong AE signal if it flies significantly below that height.
While there have been described above the principles of the present invention in conjunction with specific exemplary test equipment, methodologies and the like, it is to be clearly understood that the foregoing description is made only by way of example and not as a limitation to the scope of the invention. Particularly, it is recognized that the teachings of the foregoing disclosure will suggest other modifications to those persons skilled in the relevant art. | A system and method for the production level screening of low flying magnetic heads in the manufacture of disk drive head disk assemblies (HDAs) is disclosed. A test disk is provided and has a plurality of bumps extending from at least one surface thereof to a predetermined height between 2 and 12 nanometers. The test disk is rotated to fly a head of a head gimbal assembly selected from the group adjacent the surface of the test disk. An interaction of the head with one or more of the plurality of bumps may be sensed and the head gimbal assembly may be screened out from the group in response to the sensing of the interaction. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to apparatus for arresting and controlling a ruptured roving during operation of the draw frame of a textile spinning machine.
In U.S. application Ser. No. 387,193, filed June 10, 1982, now U.S. Pat. No. 4,501,114 (corresponding to German GE-OS31 23 476) and U.S. Pat. No. 4,484,376 issued on Nov. 27, 1984, (corresponding to German DE-OS P 31 00 049) both assigned to the assignee of the present application, a spinning machine is depicted in which each draw frame has a blocking device for arresting the ruptured roving. The blocking device may be activated by a sensor detecting the continuity of the roving being fed directly into the infeed rollers of the draw frame and/or by a sensor detecting the continuity of the thread discharged therefrom. Also, a second roving material incorporated into the basic thread after spinning can also be sensed.
When the blocking device is actuated by either one of the sensors noted, the roving is clamped and held at its entry into the first of the drawing rollers, resulting in the creation of a fiber tuft projecting from there toward the remaining drafting belts. When the blocking device is actuated by a sensor, arranged relatively prior to the entry to the rollers, the remainder of the roving, e.g., a piece broken off the roving supply or the end of the roving run off the supply spool, may still run completely into the draw frame with the result that the actuated blocking device runs idly, and does not secure a fiber tuft. Processing of material can, however, be stopped by actuation through the other sensors.
Although the blocking device known from the aforesaid application is provided with a handle which allows the deactivation of the blocking device, and resetting of the draw frame for operation, manual manipulation and several steps are still required for restarting of the spinning, i.e., providing a continuing roving supply, which are not dealt with by the aforementioned application. For example, when a blockage is caused by rupture or run out of the roving being fed from the supply spool through the draw frame, a connection to the roving supply must be first reestablished at a position outside of the draw frame, generally after the prior insertion of full supply spool. Thus, as previously mentioned, if the roving has completely run beforehand into the draw frame, or even if it is completely run beforehand into the draw frame, or even if it is projected out by only a slight degree, to the rear of the blocking site, connection with the forward end from the supply spool is impossible. It, therefore, becomes necessary to lift the upper rollers from contact with the lower rollers in order to insert the supply roving between the drawing rollers along the entire length of the draw frame.
The object of the present invention is directed to simplifying the task required for rejoining the roving within the draw frame to the roving supply and of assuring effective connection of the roving regardless of whether the rejoining is executed manually or with the aid of some mechanical apparatus.
A further object of the present invention is to provide an arrangement suitable for use on latterally coupled draw frames equipped with double upper rollers held in a support and load arm whereby rejoining of the roving and restarting of the spinning on one side has no influence or effect on the spinning rollers on the other side.
Other objects and advantages of the present invention are set forth in the following disclosure.
SUMMARY OF THE PRESENT INVENTION
In accordance with the present invention, the draw frames of a spinning machine are provided with a roving blocking device located at the point where the roving enters the rollers and a sensor detecting the continuity of the supply roving located at the rearmost point at the infeed point from the supply source so as to actuate the blocking device on the rupture of the roving entering from the supply source. The blocking device acts to lift the upper roller from the lower roller and hold the roving fast between itself and the upper roller so as to block its further movement. In addition, a roving clamp member is arranged in the area between the supply sensor and the blocking device so as to be capable of being actuated simultaneously with the blocking device into a holding position wherein the rear end of the roving is held. Thus, the roving is held not only at the rollers, but in a position closely adjacent the infeed of the roving from the supply so as to provide a tuft or portion at its rear end, freely available for reconnection to the roving supply.
The roving clamp provided between the supply sensor and the blocking device retains the rear end piece of the roving which has still not entered into the rollers of the draw frame. The sensor is arranged at such a long distance from the entry into the rollers of the draw frame that a roving end is provided, which is sufficiently long to enable its rejoining to the roving supply. Rejoining of the broken end with the roving supply can be simply effected by ordinarily twisting the two roving pieces together. Rejoining by machinery can be done, for instance, with a device movable alongside the machine, which grasps the roving end piece held fast by the holder and works the end by gripping arms or other joining means to the roving from the supply.
The free standing fiber tuft projecting into the draw frame forward of the blocking device is held by a roving support which guides the fiber tuft during its movement into the double belt twisting unit of the drawing rollers thus assuring trouble-free advance of the roving within the draw frame. In this manner a rather long length of roving is held in the draw frame from a point adjacent the infeed to the winding spool. It is, therefore, not necessary to lift the support arm receiving the upper rollers from contact with the lower driven rollers or to cause interruption of the associated series of rollers, acting on an independent roving in the adjacent frame when the rupture occurs adjacent to supply source.
Preferably, the supply sensor for the incoming roving, and the roving clamp associated therewith are mounted on a common carrier. This offers a favorable and simple means for fastening the components required for checking and maintaining the continuity of the roving and for holding the end of the roving. This permits an already operational machine to be subsequently retrofitted with the present invention. For practical reasons, the common carrier is a component of the general or normal roving blocking device such as the bearing arm for the other sensors or blocking devices associated with the exiting of the roving from, or its passage through the rollers.
The infeed roving sensor can be a mechanical device, but it is of a practical advantage to provide a photoelectric device to sense the infeed of the roving. Especially advantageous is the provision of an arcuate trough guideway between the infeed point and the clamping member, which is designed as an arcuate channel helping to direct the roving in its proper path. As such, the photoelectric cell and a light source can be arranged at its upper end within its internal periphery. The guideway also creates a supporting table, which by the development of its curvature, the end of the roving still protruding rearwardly from the roving clamp may be held. This supporting surface forms a favorable work surface for manually twisting together the ends of the roving and for piecing the roving together when automatic mechanical means are employed.
It is further preferable to couple the present invention with the roving support and holding means located between the initial infeed rollers of the draw frame and the twisting belts so that the forward end or tuft of an arrested roving can be held ready for start up and feeding to the drafting belts.
Full details of the present invention are set forth in the following description and are illustrated in the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings:
FIG. 1 is a side elevational view of a draw frame with a roving blocking device, a roving clamp device and a roving holder and infeed guide in accordance with the present invention; and
FIG. 2 is a plan view of the the draw frame shown in FIG. 1.
DESCRIPTION OF THE INVENTION
In general, the present invention is applied to a conventional draw frame of such spinning machines as disclosed in the aforementioned U.S. application Ser. No. 387,193 and U.S. Pat. No. 4,484,376. Thus only those details as are necessary for an understanding of the present invention are set forth hereinafter and reference may be made to the aforementioned application and patent for other details which are, of course, incorported herein by reference.
Each of the draw frames of the conventional spinning machine are mounted upon a supporting rod 1 which runs the length of the spinning machine transversely to a series of draw frames which are conventionally coupled in pairs. Fixedly mounted on the supporting rod 1 between adjacent couples of draw frames is a bracket support 2 on which is further pivotally mounted a load arm 3 which is provided with a handle 4. The load arm 3 is swingable about a bearing axle 5 so as to be movable in an upward-downward direction.
Depending from the load arm 3 to each side are the upper rollers 6,7, 8 for each of the coupled draw frames. The rollers 6, 7 and 8 are journalled in their respective axles so as to be freely rotatable. Fixedly mounted, by pairs, on each side of the frame of the spinning machine are the lower rollers 9, 10 and 11 which are driven to provide the forward motion for the roving and the twisting motion for converting the same into threads. The opposing rollers 7 and 10 are provided with endless belts 12 and 13 respectively, lower belt 13 running additionally over a curved palette. The slubbing or roving 14 is introduced into the draw frame at its rear end and is drawn through the first set of rollers 8 and 11 exiting at the front end from the draw frame as a thread 14'.
The continuity of the thread 14' exiting from the forward end of the draw frame is detected by a sensor S, and upon rupture or dicontinuance thereof provides a signal which activates a roving blocking device generally denoted by the numeral 15 which arrests the roving preventing it from passing completely through the rollers. The blocking device 15 comprises a shell 16 slidably arranged about the lower roller 11, which is provided with a laterally extending dome shaped projection 17 having a recess into which a stud 18 fits. The stud 18 depends from a slide member 19 which is mounted within a slot formed in a bearing rail 20. The bearing rail is arranged on the exterior side of the rollers and is secured firmly by a bracket 21 integral with clamp 22 which is itself securely fastened to the transversely extending supporting rod 1.
As seen in FIG. 2, the bearing rail 20 extends parallel to the generally horizontal path or line of travel of the roving 14. Seated on the bearing rail 20 prior to the infeed rollers 8, 11 is a housing 23 in which is located a solenoid 24, the armature of which forms a bolt 24a, which is adapted to fit within a notch 19a on the upper edge of the slide 19 so as to rest and lock the slide 19 in a fixed position. A compression spring 25, also located in the housing 23, bears against the rear edge of the slide edge 19 tending to bias the slide 19 toward the forward end of the draw frame and acting against the fixed position created by the engagement of the locking bolt 24a in the notch 19a on the upper edge of the slide 19.
On retraction of the solenoid armature from the notch in the slide 19, by actuation of the solenoid, the compression spring 25 pushes the slide 19 forwardly thereby causing the shell 16 to rotate counter-clockwise about the roller 11 placing its wedge shaped edge between the lower roller 11 and the roving below the upper roller 8. The shell 16 clamps the roving 14 between itself and the roller 8 and simultaneously lifts the roller 8 from its engagement with the driven roller 11. Actuation of the solenoid 24 is obtained for example by a signal pulse emitted from the thread sensor S. Once the solenoid is activated, the movement of the slide 19 is automatic, under the force of the pressure spring 25.
A holder, generally depicted by the numeral 26 is located in the area between the shell 16 and the twisting belts 12 and 13, to support and hold the free-standing tuft created on rupture of the thread 14' from falling below the roving drawing line, and to subsequently assure the advance of the roving to the belts 12 and 13 so as to secure and complete its run-in on subsequent start up of the machine. The tuft holder 26 comprises a bracket having a table-like center generally depicted by the numeral 27 and which is fastened by a suitable clamp onto the bearing rail 20 so as to be adjustable in position lengthwise along the rail. To assure the retention of the tuft on the support-like table 27, a clamp member in the form of a rotary shaft 27a having a flat portion on one side is provided. The rotary shaft 27a is coupled by means of a pinion with the slide 19 which is provided with a rack 28 along its lower edge. In this way the rotary shaft 27a is turned simultaneously with the movement of the slide to clamp the roving tuft firmly against the table-like support 27. Thus, the tuft is held securely at its forward end immediately preceding the belts 12 and 13, even during the subsequent cleaning of belts 12 and 13 and rollers 6 and 9 with the conventional devices such as passing an air current through the machine.
As will be seen from the foregoing which is basically the construction of the aforementioned application and patent, there exists a relatively long span from the initial roving supply point P at the rear end of the machine to the first set of infeed rollers 8, 11. As a result, when the roving is ruptured in this area, a long stretch or tuft or roving may hang down into the machine, sometimes fouling the machine, but always presenting a problem on start-up of reattaching the roving to the thread, or to the portion of the roving held in the rollers, or of inserting the broken end into the rollers.
In accordance with the present invention, means are provided enabling the control of the broken roving to simplify its introduction and joining to a new roving, or to the ruptured end of a roving and its supply into the draw frame. The present invention provides a shaped roving guide 29 arranged at the rear end of the draw frame starting from the point P and a roving clamp 30 between the guide 29 and the transverse rod 1. To accommodate the roving guide 29 and the roving clamp 30 the bearing rail 20 is extended as at 20', a substantial distance to the rear of the supporting rod 1 as is the slide, shown at 19'. The guide 29 and roving clamp 30 are secured to the bearing rail by suitable clamp means so as to be adjustable along the length thereof in the most optimum position depending on the nature of the roving length of the guide, etc. The roving clamp 30 which is similar to the earlier described holder 26 includes a supporting table 31, as well as a rotary shaft 32 which is flattened on one side and which passes over the roving. The rotary shaft 32 is provided with a pinion which meshes with a rack edge 33 on the bottom of the slide extension 19'. Thus, movement of the slide 19 causes rotation of the rotary shaft 32, simultaneously with the operation of the blocking device 15 and the roving clamp 26 described earlier.
The roving guide 29 comprises an arcuate trough-like guideway 34 shaped at its upper end as an oval ring 34', split in its periphery, to permit entry of the roving, but easy retention once it starts its travel. In cross-section, as seen in FIG. 2, the guideway 34 is also arcutate; the resultant compound curvature assuring free and easy guidance of the roving to the rollers. The lower end of the trough guide-way terminates in a horizontal position, aligned with the line of travel of the roving in the draw frame, providing a table-like surface for the end of the ruptured roving.
A light source 35 and a photo sensitive cell 36 are arranged opposite to each other on the inner wall of the ring 34' so as to sense the passage of the roving 14 into the guideway 34. The sensor 36 is adapted to produce a signal pulse on rupture of the roving prior to its entry, which signal is delivered to the solenoid 24 in the same manner as the pulse signal from the sensor S on rupture of the exiting thread 14'. The roving guide 29 is formed as a unitary bond 37 which is mounted to the bearing rail 20, at its lower end.
Power to the electrical components is supplied by the cable 38 which is connected to the common power line for the spinning machine, and which extends through the bearing rail 20.
In accordance with the present invention, the guideway 34 terminates at its lower end in substantial horizontal portion leading directly toward the surface of the table 31 of the second roving holder 30. Thus, the roving makes a smooth transition from the supply end into the drawing line. The rupture or ending of the roving 14 from the supply at the rear or feed end of the drawing frame is sensed by the sensor 36. This signal activates the solenoid which causes movement of the blocking device 15 and both roving clamps 26 and 30 simultaneously. The rear end of the roving in the draw frame is held by the clamp 30 while the forward end is held by the clamp 26. Thus, the rear end of the roving, remains within the range of the roving guideway 34 so that the ruptured roving, or a new roving, from the supply can be reconnected or connected therewith whereby a continuing roving is established prior to entry into the rollers of the draw frame.
The roving blocking device 15 is also actuated at the same time as the roving clamp 30 capturing the fiber tuft within the draw frame along the drawing line so that the forward end of the roving is held ready for twisting within the belts 12 and 13 as soon as the cause for the rupture of the roving is removed. When the cause of the roving rupture is removed, the slide 19 is returned to its normally held position in engagement with the bolt 24a of the solenoid 24. To effect this, the slide 19 is provided with an upwardly extending handle 39 which can be manually manipulated by the operator of the machine. Once the slide 19 is returned to its normal position, both of the clamps 26 and 30 as well as the blocking device 15 are returned to their normal operating position which allows the roving 14 to run smoothly and freely through the draw frame. The forward end of the roving, now being the thread 14' is conventionally connected to the thread previously wound upon a spool and continuous operation of the draw frame can be effected.
It will be noted from the foregoing, that the removal of the cause for any rupturing of the roving occuring between the supply and the first set of rollers and the reconnection of the new thread into the drawing frame itself is effected without the need to move or lift the load arm 3 or 4 disengage the rollers. Therefore, the adjacent spinning site of the paired rollers need not be disturbed and spinning at that site will not be interrupted. In other words, the stopping of drawing through one set of rollers does not effect the continued operation of its adjacent companion rollers in the paired drafting situs.
Various embodiments, modifications and changes have been mentioned here, other such variations will be obvious to those skilled in this art. Accordingly, the present disclosure is to be taken as illustrative and not as limiting of the present invention. | A draw frame for a spinning machine is provided with roving blocking mechanism associated with its inlet rollers actuable on rupture of the remittant thread to arrest movement of the roving and is further provided with a sensor for detecting the continuity of the roving being fed from a source of supply and a roving clamp situated between the sensor and the blocking mechanism. The blocking mechanism and the roving clamp are arranged to be simultaneously operated in response to a signal from the sensor or in response to rupture of the thread. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit, under 35 U.S.C. Section 119(e), of co-pending provisional application No. 60/553,888, filed Mar. 17, 2004, the disclosure of which is incorporated herein by reference.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] The present invention relates to a method of applying and distributing a charge of a particulate material onto a top surface of a substrate, such as a pizza or lasagne batter or one or more open sandwiches. The present invention further relates to an apparatus for the application and distribution of the charge of the particulate material onto the top surface of the substrate, such as a pizza or lasagne batter.
[0004] Within the technique, several technical solutions for the application and distribution of a charge, such as a charge of a specific foodstuff constituent or a mixture of different foodstuff constituents are known, in particular in relation to the production of pizzas as the particulate material is applied onto a pizza batter.
[0005] An approach as to evenly distribution of particulate material onto a substrate, such as a pizza batter, is described in applicant's issued U.S. patent U.S. Pat. No. 6,531,170, to which reference is made and which U.S. patent is also incorporated in the present specification by reference. Further examples of the prior art techniques of applying and distributing a charge of a particulate material onto a pizza batter are described in U.S. Pat. Nos. 5,678,476 and 6,598,519. According to the technique known from U.S. Pat. No. 5,678,476, a hopper is used for the delivery of e.g. cheese to a food spreader having a plurality of movable paddles mounted within the housing of the food spreader which housing further has a porous bottom member positioned below the movable paddles and above the pizza batter onto which the cheese is to be spread. According to the technique known from U.S. Pat. No. 6,598,519, the diffuser has a housing in which a rotatable axle is journaled and from which axle a set of radial paddles extend. The paddles are stated to cause the charge to be broken up and distributed over a wide area and for guiding the deposition of the particulate material, in particular cheese particles. Furthermore, downwardly extending stationary rods are provided within the housing.
[0006] Although the prior art distributor apparatuses claim to allow the particulate material, in particular the particulate cheese, to be broken up and distributed evenly, experiments which the applicant company has performed reveal that the charge, when delivered to the distributor, tends to block the even distribution of the material, and therefore the prior art distributors based on rotatable paddles or similar radial blades or paddles have turned out not to function entirely satisfactorily.
[0007] Reference is made to the above U.S. patents which are further hereby incorporated in the present specification by reference.
[0008] The use of rotating paddles or blades for distributing particulate material, e.g. cheese, on a pizza batter, may, apart from the problems of obtaining even distribution of the material, which even distribution may be influenced by the blocking of the material when introduced into the distribution apparatus, further involve certain problems, as the mechanical impact to the material when distributed or spread by means of the rotating paddles or blades may deteriorate the particulate material and generate a chopping of the material rather than a distribution of the material. Consequently, provided that the prior art rotating paddle or blade distributors are to be improved for providing an even distribution, a risk exists of deteriorating the material by simple chopping the material due to excessive mechanical impact to the particulate material.
SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to provide a simple and reliable technique for the application and distribution of a particulate material onto a substrate, such as a pizza or lasagne batter, e.g. the distribution of particulate foodstuff onto a pizza or lasagne batter, which technique ensures an even distribution of the particulate material onto the substrate without imposing excessive mechanical stresses or impact to the particulate material which might otherwise cause the material to be chopped, and at the same time carrying out an efficient and gentle distribution and providing a reliable and fast distribution.
[0010] It is a further advantage of the present invention that the technique of applying and evenly distributing a particulate material onto a substrate such as a pizza or lasagne batter, apart from imposing a minimum impact to the particulate material, causes a minimum wear to the components of the apparatus and at the same time allows the apparatus to be implemented as a simple and reliable apparatus.
[0011] The above object and the above advantage together with numerous other objects, features and advantages will be evident from the following detailed description of the presently preferred embodiment of the technique according to the present invention and in accordance with the teachings of the present invention obtained by a method of applying and distributing a charge of particulate material onto a top surface of a substrate, such as a pizza or lasagne batter, comprising:
providing the charge, providing a two part separator, a first part of which constitutes a delay line having a first input and a first output, for receiving the charge through the first input, for delaying the transfer of the charge through the delay line and for discharging the charge from the first output, and a second part of which constitutes a diffuser having a second input and a second output, for receiving the charge from the first output of the delay line through the second input and for delivering the charge after spreading the charge through the second output, moving the substrate and the two part separator relative to one another for positioning the substrate below the two part separator in a position in registration with the second output, delivering the charge to the first input, and moving the substrate and the two part separator relative to one another after the distribution of the charge onto the substrate for removing the substrate from the position below the second output of the two part separator.
[0017] According to the teachings of the present invention, the application of a particulate material onto the substrate is established in a two step operation by means of the two part separator as the particulate material is initially delayed in its transfer through the delay line constituting the first part of the separator before the particulate material is spread by means of the diffuser constituting the second part of the separator. According to the experiments which the applicant company has performed as mentioned above, the function of the diffuser, which may be implemented as a conventional rotor blade or rotor paddle distributor, is improved in terms of even distribution of the particulate material by the delay of the introduction of the material into the diffuser by means of the delay line, and at the same time, through the improved functionality of the diffuser, the mechanical impact to the particulate material, when spread by means of the diffuser is reduced as compared to a conventional rotatable blade or paddle distributor operated for optimum distribution efficiency.
[0018] It is a characteristic feature of the present invention that the delay line serves to increase the time of discharge of the charge from the first output of the delay line relative to the time for receiving the charge through the first input of the delay line by at least about 25%, such as 25%-800%. e.g. 25%-50%, 50%-75%, 75%-100%, 100%-150%, 150%-200%, 200%-250%, 250%-300%, 300%-350%, 350%-400%, 400%-500%, 500%-600%, 600%-700%, 700%-800%, e.g. 50%-700%, such as 300%-500%.
[0019] According to the preferred embodiment of the method according to the present invention, the delivery of the charge to the first input is preferably carried out by means of an overhead hopper, preferably an openable hopper which delivers the charge to the first input of the separator in a precise and accurate manner.
[0020] The movement of the substrate and the two part separator relative to one another may be accomplished in any appropriate manner well known in the art per se by moving the substrate relative to the two part separator or alternatively moving the two part separator relative to the substrate.
[0021] According to a first embodiment of the method according to the present invention, the steps of moving the substrate and the two part separator relative to one another consequently include keeping the two part separator stationary and moving the substrate by means of a conveyor belt relative to the two part separator or by means of any other conveyor means, e.g. a moving table or similar apparatus.
[0022] According to an alternative embodiment of the method according to the present invention, the steps of moving the substrate and the two part separator relative to one another comprise moving the two part separator intermittently and in synchronism with the substrate by means of a conveyor belt or any similar appliance or apparatus while delivering the charge to the first input of the two part separator.
[0023] In order to improve the efficiency of the delivery and distribution of the charge of particulate material to the substrate, the method according to the present invention further advantageously comprises a step of moving the two part separator and the substrate relative to one another by approaching the two part separator and the substrate relative to one another while delivering the charge to the first input and distributing the charge onto the substrate, e.g. by lowering the two part separator onto the underlying substrate.
[0024] The above object and the above advantage together with numerous other objects, features and advantages will be evident from the below detailed description of the presently preferred embodiment of the technique according to the present invention and in accordance with the teachings of the present invention obtained by an apparatus for applying and distributing a charge of a particulate material onto a top surface of a substrate, such as a pizza or lasagne batter, comprising
a delivering means for delivering the charge, a two part separator, a first part of which constitutes a delay line having a first input and a first output, for receiving the charge through the first input, for delaying the transfer of the charge through the delay line and for discharging the charge from the first output, and a second part of which constitutes a diffuser having a second input and a second output, for receiving the charge from the first output of the delay line through the second input and for delivering the charge after spreading the charge through the second output, and motion generating means for moving the substrate and the two part separator relative to one another for positioning the substrate below the two part separator in a position in registration with the second output, and for removing the substrate from the position below the second output after the distribution of the charge onto the substrate.
[0028] The apparatus according to the present invention is preferably implemented in accordance with the above described features of the method according to the present invention for carrying out any of the above embodiments of the method according to the present invention. Still further, the apparatus is preferably and advantageously implemented in accordance with the below-described advantageous embodiments of the apparatus, as the second output of the diffuser of the two part separator is preferably configured corresponding to the outer contour of the substrate and may consequently be circular (provided that the substrate is a circular pizza batter), or rectangular (provided that the substrate is a rectangular lasagne batter). Provided that the apparatus is used for any other application and distribution of any other charge of particulate material, in particular foodstuff material on a different kind of substrate, the second output of the diffuser of the two part separator may be differently configured for complying with specific requirements.
[0029] According to the presently preferred embodiment of the apparatus according to the present invention, the delay line is constituted by a tubular chamber having a first axle rotatably mounted within said tubular chamber and including a plurality of blades extending radially from said first axle, said plurality of blades being positioned within said tubular chamber so as to block the free transfer of said charge through said tubular chamber, and said diffuser having a housing and a second axle rotatably mounted within said housing and including a plurality of rods extending radially outwardly from said axle and being rotated with said axle.
[0030] The number of blades of said plurality of blades together with the rotational speed when rotating said blades influence the separation of the particulate material of the charge when the charge is transferred through the delay line. Experiments have revealed that a large number of blades of said plurality of blades increases the time of transfer of the charge through the delay line and consequently provides an excellent separation, whereas the separation is deteriorated if only a fairly low number of blades be used. Through the experiments which the applicant company has performed, it has been realized that the number of blades of said plurality of blades may vary from 4 to 12, and a number within the range of 6-9 blades (such as 6 or 7 blades) conventionally provides an adequate and sufficient separation for most application purposes.
[0031] The delay line according to the above described presently preferred embodiment of an apparatus according to the present invention includes, according to a specific feature of the present invention, a plurality of blades which preferably constitute blades being mounted centrally on the first axle and being positioned in an orthogonal system or any other angular mutual relationship for blocking the free transfer of the charge through the tubular chamber. The blades, which are preferably positioned horizontally, allow the individual particles of the particulate material of the charge to rest for a short period of time on the blades before falling through the tubular chamber to a lower positioned blade and finally before delivery to the second input of the diffuser. The diffuser being implemented as a rotor blade diffuser may have a separate axle, or, according to the presently preferred embodiment of the apparatus according to the present invention, one and the same through-going axle as the delay line.
[0032] The diffuser being implemented as a rotor blade diffuser may be configured having a different number of rotor blades or impinging pins, such as a number varying from 3 to 10, and the rotor blades or the impinging pins may be configured as rectilinear rods or curved rods as will be evident from the following detailed description of the presently preferred embodiment of the apparatus according to the present invention. The choice of number of separation blades and also diffuser blades and the choice of the specific configuration of the diffuser blades or impinging pins of the rotor blade diffuser depend on the particulate material of the charge in question and also the consistency of the particulate material, which for some applications, is frozen, whereas for other applications, the particulate material may be non-frozen. As a general rule, the provision of a large number of impinging pins or diffuser blades improves the evenly distribution of the particulate material.
[0033] A particular aspect of the present invention relates to a sector ring assembly which is used as a separate component or an integral component of the apparatus for the application and diffusion of the charge of the particulate material according to the present invention. If the particulate material is e.g. frozen chopped vegetables or other frozen constituents, the collision between the frozen particulate material and the substrate such as a pizza batter, lasagne batter or open sandwiches may be a non-elastic collision, and consequently the frozen particulate material tends to rebound from the substrate which may cause the particulate material to be reorganized, and consequently, due to the impact generated by the rotor blade diffuser, be collected unevenly and non-randomly on the supporting substrate. In order to prevent the particulate material to be reorganized, a sector ring assembly is preferably used, which sector ring assembly comprises a number of radial walls connected circumferentially by an outer circumferential wall and one or more intermediate partition walls. By the provision of a sector ring assembly, the walls of which are preferably of a height of 20-40 mm, such as 25-35 mm, any uneven or non-random reorganization of the particular material is to any substantial extent prevented. The actual height of the walls of the sector ring assembly depends on the particulate material in question and also on the velocity of the individual particles of the particulate material when colliding with the supporting substrate, and consequently of the impact force generated by the diffuser being a rotor blade diffuser or any other randomly distributing diffuser.
[0034] As stated above, the sector ring assembly constitutes an advantageous component of the apparatus according to the present invention. It is contemplated, however, that the sector ring assembly may be implemented in other diffuser structures, and furthermore, it is contemplated that the sector ring assembly may geometrically be adapted to the geometrical configuration and size of the diffuser housing, and consequently the geometry and size of the substrate or the substrates, normally being a pizza batter, a lasagne batter or one or more open sandwiches.
[0035] Dependent on the particulate material to be applied and distributed on the substrate, being a pizza or lasagne batter or any other foodstuff substrate, the through-going axle of the two part separator may rotate at a speed of 100 rpm-1000 rpm, such as 200 rpm-600 rpm, preferably 300-400 rpm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The invention is now to be further described with reference to the drawings in which:
[0037] FIG. 1 is a schematic, partly cutaway elevational view of a first embodiment of a distribution system for distributing two charges of particulate material, such as a chopped foodstuff, onto underlying substrates, e.g. pizza or lasagne batter, illustrating a first step of the application and distribution of the charges;
[0038] FIG. 2 is a view similar to FIG. 1 , illustrating a further step of the application and distribution of the charges;
[0039] FIG. 3 is a perspective, schematic and partly cutaway view of a prototype embodiment of an apparatus for applying and distributing a charge such as a charge of foodstuff onto the top surface of e.g. a pizza batter;
[0040] FIG. 4 is a view similar to the view of FIG. 3 of a slightly modified version of the prototype embodiment of the apparatus according to the present invention;
[0041] FIG. 5 is a perspective, schematic and partly cutaway view of a further embodiment of the apparatus according to the present invention which further embodiment is modified as compared to the embodiment shown in FIGS. 3 and 4 by the adaptation of the apparatus for application and distribution of a charge of particulate material onto a rectangular substrate such as a lasagne batter; and
[0042] FIG. 6 is a top view of the further embodiment of the apparatus shown in FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
[0043] In the below description, a technique of applying ingredients is described, such as specific foodstuff constituents e.g. olives, chopped peppers, chopped tomatoes, chopped onion, chopped artichokes, chopped mushrooms, chopped ham, chopped beef, chopped pork, chopped mutton, chopped chicken, chopped turkey in fresh, boiled, roast or smoked form, chopped or cut-up fish, including fresh, roast, boiled or smoked fish parts of, for example mackerel, tuna, herring, flaffish, codfish, salmon, sea trout, etc., and combinations of such foodstuff ingredients, onto a piece of dough, in particular a batter or a paste, more particular onto a pizza batter, before the baking of the batter or dough piece, or alternatively onto a piece of bread or similar substrate. In particular, the below description refers to the application of constituents, being foodstuffs constituents, onto a pizza batter. Still, it is contemplated that the technique and the apparatus and methods implementing the present invention may advantageously be used in similar applications for the application and even distribution of constituents onto a substrate, preferably within the field of food processing.
[0044] In FIG. 3 , a first and presently preferred embodiment of the apparatus for the application and distribution of a charge of particulate material, in particular foodstuff, onto a substrate, in particular a pizza batter, is shown. The apparatus shown in FIG. 3 is in its entirety designated by the reference numeral 50 . The apparatus comprises three parts: an inlet part 10 , a delay line 12 and a diffuser 14 . The inlet part 10 is constituted by a conical hopper 16 which receives a charge of particulate material, illustrated as particles, one of which is designated the reference numeral 20 . The conical hopper 16 terminates at an upper input of a delay line 12 , which delay line is configured as a tubular chamber 22 having a circular cylindrical cross section and in which a through-going axle 24 is mounted. The axle 24 is driven by a motor assembly 26 , which motor assembly is connected to the through-going axle 24 in a fitting 28 . The direction of rotation of the axle 24 is indicated by an arrow 30 .
[0045] The through-going axle 24 which extends from above the input of the delay line 12 to below the output of the delay line 12 is provided with a plurality of blades 32 extending radially from the through-going axle 24 as the blades are positioned centrally of the through-going axle 24 . In total, six blades 32 are advantageously provided. The blades 32 have a major dimension somewhat smaller than the inner diameter of the tubular chamber 22 for allowing the blades to rotate driven by the through-going axle 24 within the tubular chamber, and a minimum dimension which is substantially smaller than the inner diameter of the tubular chamber 22 corresponding to 50%-60% of the inner diameter of the tubular chamber 22 . The blades are positioned in an orthogonal system in which the first or top blade extends in one direction perpendicular to the through-going axle 24 and the next blade extends perpendicular to the first blade and so forth. Although the blades are shown extending perpendicular to the axle 24 , the blades may be configured as V-shaped blades or simply define an angle different from 90° relative to the through-going axle 24 if, e.g., larger particles are to be applied and distributed, in which case an angular position of the blades 32 may be advantageous.
[0046] Basically, the blades 32 serve to block the free transfer of particles falling through the tubular chamber 22 of the delay line 12 as the particles are, to a major extent, stopped and arrested on the top blade, as indicated schematically in FIG. 3 , whereupon the particles drop to the second blade as some of the particles simply fall freely past the rotating blades, and as a result of the delaying of the free fall through the tubular chamber 22 , the time of transmission of the charge of particulate material through the delay line 12 is extended, providing a separation of the particulate material which is delivered from the lower output of the tubular chamber 22 to an input of the diffuser 14 .
[0047] The diffuser 14 is constituted by a larger diameter cylindrical housing 34 as compared to the tubular chamber 22 and has its inner diameter configured somewhat smaller than the outer diameter of a pizza batter 36 which is positioned at the lower output of the diffuser 14 , however, circumferentially encircled by the lower rim part of the housing 34 . The housing 34 is composed of an outer circular cylindrical wall 38 and a top wall 40 providing a sealed inner chamber within the housing 34 of the diffuser 14 .
[0048] Within the inner chamber defined within the diffuser 14 , the through-going axle 24 has at its lower end a plurality of transversal expeller rods which extend perpendicular to the through-going axle 24 . Like the blades 32 , the rods, one of which is designated by the reference numeral 42 , may be configured differently, as is illustrated, e.g., in FIG. 4 , in which a plurality of rods 42 ′ having the configuration of a segment of a sinusoidal curve are used as a substitute for the rectilinear rods 42 shown in FIG. 3 . Furthermore, the rods may be differently configured, e.g., configured as V-shaped rods defining an angular relation with the through-going axle 24 different from the orthogonal system shown in FIG. 4 . The rods 42 basically serve as expeller rods which hit the particles discharged from the delay line 12 and throw the particles randomly in different directions, for causing the particles to be evenly distributed on the pizza batter 36 .
[0049] It is a distinct feature of the apparatus shown in FIG. 3 that the particulate material is contacted individually with the expeller rods 42 , as the charge of particulate material is delayed in its transfer through the delay line 12 , and thereby the batch or charge initially input to the delay line 12 by means of the hopper 16 is caused to contact the expeller rods 42 individually rather than having the whole charge contacted with the rods, which then have to serve the dual purpose of separating the charge into individual particles and also of spreading the particles randomly within the diffuser chamber for providing an even distribution of the particulate material on the pizza batter 36 .
[0050] According to a particular feature of the apparatus shown in FIG. 3 , a sector ring assembly is provided at the lower end, i.e. the output of the diffuser 14 . The sector ring assembly serves the purpose of preventing particulate material which has been randomly distributed within a diffuser to be reflected in a non-elastic or elastic collision with the substrate, i.e. for causing the particulate material to be distributed according to the pattern of impact, as the particulate material is individually colliding with the supporting pizza batter 36 . The sector ring assembly is in its entirety designated by the reference numeral 80 and comprises a number of radially extending separation walls, such as 4-12 separation walls, e.g. 6 or 8 radially extending separation walls, as is illustrated in FIG. 3 . One of the radially extending separation walls is designated by the reference numeral 82 . The sector ring assembly further comprises an outer circumferential ring-shaped wall 84 and one or more intermediate circular sector ring walls subdividing the generally triangularly formed chambers defined between any two adjacent radially extending separation walls into two or more sub-chambers. In FIG. 3 , a single intermediate circular sector wall is shown and designated by the reference numeral 86 . The walls 82 , 84 and 86 have a height sufficient to prevent the particulate material from being shifted from one subsection of the pizza batter 36 delimited by the sub-chamber of the sector ring assembly to another section, and consequently the walls 82 , 84 , 86 prevent a complete reorganization of the particulate material after the particulate material has collided with the supporting substrate, which reorganization might else cause a non-random distribution of the particulate material.
[0051] In FIG. 4 , an apparatus 50 ′ similar to the apparatus 50 shown in FIG. 3 is illustrated, which apparatus 50 ′ differs from the above described apparatus 50 as already discussed above, as the rectilinear rods 42 shown in FIG. 3 are replaced by curved rods 42 ′.
[0052] The technique of performing a two part application and distribution of a charge of particulate material of, in particular, foodstuff may be modified in numerous ways as already indicated above. For applying particulate foodstuff onto a substrate different from the circular substrate constituting a pizza batter 36 illustrated in FIGS. 3 and 4 , a lasagne batter 36 ′ shown in FIG. 5 may be provided, and the apparatus used for applying the particulate foodstuff onto the lasagne batter may be configured having a diffuser 14 ′ configured in conformity with the size and dimensions of the lasagne batter 36 ′. In the below description, components or elements identical to components or elements described previously are designated by the same reference numbers, whereas components or elements having the same function as components or elements previously described, however differing in shape or otherwise from the components or elements previously described are designated by the same reference number, however with an added marking for indicating the geometric or otherwise difference from the previously described component or element.
[0053] In FIG. 5 , the diffuser 14 ′ is composed of an outer wall section 38 ′ having a rectangular cross section and a rectangular top wall 40 together defining a rectangular inner chamber in conformity with a rectangular configuration of the lasagne batter 36 ′. Apart from the different geometric configuration of the diffuser 14 , the apparatus 50 ″ differs from the above described embodiments 50 and 50 ′ shown in FIGS. 3 and 4 , respectively, in that guiding plates are provided, one of which is designated by the reference numeral 48 . A total of four guiding plates 48 , constituting diverging fins, are provided.
[0054] In FIG. 6 , a top view of the apparatus 50 ″ shown in FIG. 5 is presented, illustrating the guiding plates 48 in greater detail. Like the expeller rods 42 shown in FIGS. 3 and 5 , the guiding plates 48 may be configured in numerous ways in conformity with the size and configuration of the substrate in question and also in correspondence with the flexibility, weight, etc. of the particulate material to be evenly distributed on the substrate by means of the apparatus.
[0055] In FIGS. 1 and 2 , a system for the application and distribution of particulate material onto pizza batters is shown. The system is in its entirety designated by the reference numeral 60 , and the individual pizza batters are equidistantly positioned on a conveyor belt 62 which is moved around a drive roller 64 and an idler roller 65 powered by a motor 66 which is controlled by an overall system controller 68 . A total of two apparatuses according to the present invention are shown, which apparatuses 50 are in FIG. 1 in a raised position as the individual apparatus 50 is journalled on a pair of rollers 70 , 72 , which rollers co-operate with a through-going rail 74 . The rail 74 is suspended in a pair of vertically reciprocating pneumatic cylinders 76 and 78 which are activated from the central controller 68 for causing the assembly, including the rail 74 and the two apparatuses 50 , to be raised, as illustrated in FIG. 1 , above the pizza batters 36 positioned below the apparatuses 50 ; whereas in FIG. 2 , the apparatuses 50 are lowered for circumferentially encircling the pizza batters 36 . Apart from raising and lowering the apparatuses 50 by raising and lowering, respectively, the rail 74 by means of the pneumatic cylinders 76 and 78 , the apparatuses 50 may be moved in synchronism with the underlying pizza batters 36 driven by an electric motor 90 for causing the apparatuses 50 to be moved from the left-hand position shown in FIG. 1 to the right-hand position in FIG. 2 . At the same time the actuation of the pneumatic cylinders 76 and 78 causes the rail 74 and at the same time the apparatuses 50 to be lowered into contact with the top surface of the belt 62 . Like the motor 60 and the pneumatic cylinders 76 and 78 , the electric motor 80 is controlled by the central controller 68 .
[0056] For the input of the particulate material to the inlet hopper 16 of the apparatuses 50 , a total of two charge dispensers 88 are positioned above the apparatuses 50 . The charge dispensers 70 are also controlled by the central controller 68 for causing the dispensing of a specific charge having a specific weight or alternatively a specific volume. No detailed description of the charge dispensers is given since the technique of dispensing a charge of particulate material is considered common knowledge within the technical field of foodstuff processing.
[0057] Although the present invention has above been described with reference to a variety of advantageous embodiments and in the context of a specific system for the application of two charges of particulate material, the invention may obviously be employed or modified in numerous ways, as e.g., the conveyor belt 62 used for the transfer of the individual substrates being pizza batters, lasagne batters or any other foodstuff product may be modified from the continuously operating conveyor belt 62 described with reference to FIGS. 1 and 2 into an intermittently operating conveyor belt or combined with an intermittently operating transfer table which allows the application and distribution apparatus according to the present invention to be a stationary apparatus rather than an apparatus to be moved on a rail or similar supporting structure, as is illustrated in FIGS. 1 and 2 . All embodiments or variations of the above kind which may be considered based on common technical knowledge are to be construed as part of the present invention, as the invention is to be interpreted in the broad scope of the following claims. | A method of distributing a charge of particulate material onto a substrate employs a separator having a first part including a first input, a first output, and a delay line for delaying the transfer of the charge from the first input to the first output; and a second part including a diffuser with a second input that receives the charge from the first output, and a second output through which the charge is spread and delivered to the substrate. The substrate and the separator are moved relative to one another for positioning the substrate below the separator in registration with the second output, and the charge is delivered to the first input. After the charge is distributed onto the substrate, the substrate and the separator are again moved relative to one another to remove the substrate from the position in registration with the second output. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to an internal combustion engine of the fuel injection type and more particularly to an improved induction system for such an engine.
It is well known that the idle and low speed running conditions of an internal combustion engine offer the most difficult phase in which to control fuel economy and exhaust emissions. Although fuel injection systems have been proposed as a possible solution to this problem, the systems heretofore known have not completely solved the problems of low speed running. Specifically, the fuel injection nozzle discharges at a relatively high pressure. At low speeds the air is flowing very slowly through the induction system and the likelihood of wetting of the induction system passages is extremely great. Of course, if the liquid fuel impinges on the induction system passages poor running results, which is normally compensated for by providing an over-rich mixture under this condition. In addition to adversely affecting fuel economy, the use of such over-rich mixtures aggravates the problem of exhaust emission control.
It is, therefore, a principal object of this invention to provide an improved fuel injected internal combustion engine that offers significant improvements in performance at low speeds.
It is another object of the invention to provide an induction system for a fuel injected internal combustion engine that minimizes the likelihood of fuel condensation at low speeds.
SUMMARY OF THE INVENTION
A first feature of this invention is adapted to be embodied in an internal combustion engine having a variable volume chamber in which combustion occurs. An internal combustion system is provided for the chamber consisting of a main intake passage and an auxiliary intake passage each of which communicate with the chamber through the respective main and auxiliary intake ports. The auxiliary intake passage has an effective cross sectional area that is substantially less than that of the main intake passage for causing a given mass flow of charge to enter the chamber from the auxiliary intake passage at a significantly greater velocity. Valve means control the ratio of communication of the ports with the chamber during a given cycle of engine operation. The inlet to the auxiliary intake passage is in communication with the main intake passage. In accordance with this feature of the invention, a fuel injection nozzle is provided which discharges into the main intake passage and in a direction toward the auxiliary intake passage inlet.
Another feature of this invention is adapted to be embodied in an engine having main and auxiliary intake passages as set forth in the preceding paragraph. In accordance with this feature of the invention, the valve means which control the ratio of communication of the ports with the chamber includes a butterfly type throttle valve rotatably positioned in one of the intake passages. Also in accordance with this feature of the invention, a fuel injection nozzle discharges into the one induction passage in a direction to impinge upon the butterfly type throttle valve in at least certain positions of such throttle valve.
Another feature of this invention is adapted to be embodied in an induction system for an engine having an induction passage that delivers a charge to a variable volume chamber of the engine. A pair of fuel injection nozzles are incorporated each of which discharge into the induction passage, one upstream of the other. Means alternately cause first one of the nozzles to discharge fuel and then the other of the nozzles to discharge fuel so that the discharge of fuel from the nozzles is not coextensive.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a bottom plan view showing the underside of a cylinder head of an induction system of an internal combustion engine embodying this invention and is taken generally along the line 1--1 of FIG. 2.
FIG. 2 is a vertical cross sectional view of the embodiment shown in FIG. 1 and is taken generally along the line 2--2 of FIG. 1.
FIG. 3 is a partial cross sectional view, in part similar to FIG. 2, showing another embodiment of the invention.
FIG. 4 is a partial cross sectional view, in part similar to FIGS. 2 and 3 showing a third embodiment of the invention.
FIG. 5 is a cross sectional view, in part similar to FIG. 2, showing a still further embodiment of the invention.
FIG. 6 is a bottom plan view of the cylinder head and induction system of the embodiment of FIG. 5, with a portion broken away, and is taken generally along the line 6--6 of FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Before beginning a detailed description of each embodiment of the invention, it is pointed out that the several embodiments have many components which are common with each other. Because of the similarity of certain components of the various embodiments and their similar function, the similar components have only been described in conjunction with the embodiment of FIGS. 1 and 2. Where these components are used in other embodiments, they are identified by the same reference numerals and the description of them is not repeated, except as may be necessary to understand the application of the invention to the particular embodiment in question.
A first embodiment of this invention is shown in FIGS. 1 and 2 and is adapted to be incorporated into an internal combustion engine, indicated generally by the reference numeral 11. The engine 11 in the illustrated embodiment is of the four cylinder in-line type but it is to be understood that the invention is susceptible to the use of other cylinder numbers and configurations as well as with rotary type engines.
The engine 11 includes a cylinder block 12 in which cylinder bores 13 are formed. Pistons 14 are supported for reciprocation within the cylinder bores 13 and are connected in a known manner to the engine output shaft (not shown). A cylinder head, indicated generally by the reference numeral 15 is affixed to the cylinder block 12 and has cavities 16 aligned with each of the cylinder bores 13. The cavities 16, cylinder bores 13 and pistons 14 define chambers of variable volume in which the combustion occurs. These chambers will, at times, hereinafter be referred to as combustion chambers.
Main intake passages 17 are formed in one side of the cylinder head 15 and terminate at main intake ports 18 which communicate with the respective chambers 16. Intake valves 19 control the flow through the main intake passages 17 and are operated in any known manner, as by means of an overhead mounted camshaft (not shown). The side of the cylinder head 15 opposite to the main intake passages 17 is formed with exhaust passages 21 which extend from each chamber 16 to an exhaust manifold, indicated generally at 22. Exhaust valves 23, which are also operated by means of an overhead camshaft (not shown) control the communication between the chamber 16 and the exhaust passages 21.
The engine as thus far described is conventional and, for that reason, a more detailed description is not believed to be necessary. The invention finds its place in the fuel injection system and induction system, now to be described. The induction system includes an air inlet 24 in which an air flow detector 25 is provided. The air flow detector 25 rotates to a position dependent on the air flow through the inlet 24 and controls the amount of fuel discharged, as will become apparent. The inlet 24 is connected by means of a flexible conduit 26 to an intake casting 27 of an intake manifold, indicated generally by the reference numeral 28. The intake casting 27 has an air inlet 29 in which a manually operated throttle valve 31 is supported for rotation upon a throttle valve shaft 32. Downstream of the manually operated throttle valve 31, a control valve 33 is supported upon a control valve shaft 34. The control valve 33 is operated automatically, in a manner to be described.
The passage 29 discharges into a plenum chamber 35 of the intake manifold 28. Runners 36 extend from the plenum 35 to the individual main cylinder head intake passages 17 so that a charge will be delivered from the induction system to the respective chambers 16.
In order to permit the induction of a charge to the chamber 16 at high velocity under low load conditions, an auxiliary induction system is also provided. The auxiliary induction system includes an inlet 37 that is formed in the manifold casting 27 and is in registry with the passage 29 between the throttle valve 31 and the control valve 33. The inlet 37 is connected with a vertically extending passage 38 which, in turn, communicates with a horizontally extending passage 39 which terminates at a transverse distribution passage 41.
Auxiliary intake runners 42 are formed in the cylinder head 15 for each chamber 16. The runners 42 extend from the transverse passage 41 through the cylinder head 15 and terminate in auxiliary intake ports 43 that are juxtaposed to the heads of the intake valves 19 and the main intake ports 18. The effective cross sectional area of the auxiliary induction system, which has been described, is substantially less than that of the main induction system so that a given mass flow of charge entering the chambers 16 through the auxiliary induction system will pass at a significantly higher velocity. The close proximity between the ports 18 and 43 insures that substantially none of this velocity will be dissipated upon induction into the chamber 16.
The control valve 33 is operated in a manner so that substantially all of the idle and low speed charge requirements of the chamber 16 will be provided through the auxiliary induction system. As load on the engine increases, an increasing proportion of the charge will be supplied through the main induction system. In order to achieve this result, the control valve 33 is operated by means of a vacuum actuator, indicated generally by the reference numeral 44. The vacuum actuator 44 includes an outer housing 45 in which a flexible diaphragm 46 is positioned. The diaphragm 46 divides the housing 45 into an atmospheric chamber 47 and a vacuum chamber 48. The chamber 47 is vented to atmospheric pressure by an atmospheric vent (not shown) or by means of a clearance between the housing 45 and a link 49 that is connected to the diaphragm 46. The opposite end of the link 49 is pivotly connected to a lever 51 that is affixed to the control valve shaft 34 for rotatably positioning the control valve 33. The chamber 48 is exposed to induction system pressure by means of a conduit 52 that interconnects the chamber 48 with a vacuum port 53 formed in the manifold casting 27. A spring 54 is positioned in the vacuum chamber 48 so as to normally urge the control valve 33 toward a fully opened position.
A charge is formed for the chambers 16 by means of a pair of fuel injection nozzles 54 and 55. The nozzle 54 is supported in the casting 27 upstream of the manually operated throttle valve 31. In a similar manner, the nozzle 55 is supported in the casing 27 and discharges into the passage 29 between the manually operated throttle valve 31 and the control valve 33. It should be noted from an inspection of FIG. 2 that the nozzles 54 and 55 are disposed on one side of the passage 29, this being the side on which the upstream peripheral edges of the throttle and control valves 31, 33 lie. Furthermore, the nozzles 54 and 55 are directed so that the centerline of their discharge intersects the respective shaft 31, 34 in a generally perpendicular direction. It should be readily apparent from an inspection of this figure that the nozzles 54 and 55 will discharge against the body of the respective valve 31, 33 throughout the full angular position of the respective valve. Thus, the likelihood of fuel issuing a high pressure from the nozzles 54, 55 striking on the wall which defines the passage 29 will be substantially minimized. Thus, any fuel which might be deposited upon the respective valve 31, 33 will be reintroduced into the air flow particularly due to the fact that the air passes with a relatively high velocity across each respective valve surface, regardless of the engine speed.
It should also be noted that both valves 31 and 33 are inclined downwardly so that any fuel deposited upon them from the nozzles 54 and 55 will be directed toward the auxiliary induction system 37. Thus, any such liquid fuel will tend to be drawn into the auxiliary induction system where the air is flowing at high velocity due to the relatively small cross sectional area. Thus, vaporization of any such liquid fuel will be insured prior to induction into the chambers 16.
FIGS. 1 and 2 illustrate the engine running in its idle condition. In this condition, the throttle valve 31 will be fully closed as shown by the solid line view in FIG. 2. It should be noted that the throttle valve 31 is slightly smaller in diameter than the passage 29. The clearance there between serves to provide the idle air flow. If desired, an additional bypass passage 56 may also be provided around the idle position of the throttle valve 51. The amount of bypass idle air is controlled by an adjustable needle valve 57. When the engine is idling, there will be a substantially high induction system vacuum which is transmitted from the port 53 through the conduit 52 to the chamber 48. The atmospheric pressure acting in the chamber 47 will, therefore, cause the diaphragm 46 to move to the left and compress the spring 54. This causes the control valve 33 to be moved to its fully closed position. Thus, all idle air flow will be delivered to the chambers 16 through the auxiliary induction system.
In order to improve fuel control, the nozzles 54, 55 are arranged so as to fire alternately. That is, the nozzle 54 will discharge during the induction cycle of one chamber 16 and the nozzle 55 will be fired during the induction cycle of the next chamber in sequence. Thus, each nozzle need only serve half the requirements of the complete engine. The amount of fuel delivered to the nozzles 54 and 55 is controlled as previously noted by the angular position of the air flow detector 25 by means of any known type of control device.
As the load on the engine is increased or as the speed is increased, the manually operated throttle valve 31 will be progressively opened. As the valve 31 continues to open and load and/or speed increases, the induction system vacuum will fall. Eventually a point will be reached when the atmospheric pressure in the chamber 47 is no longer sufficient so as to maintain the control valve 33 in its closed position. When this occurs the spring 54 will cause the control valve 33 to begin to open and an increasing proportion of the charge requirements for the engine will be delivered through the main induction system.
In order to further improve fuel vaporization under low temperature conditions, a hot spot 58 is provided in the manifold 28 underneath the auxiliary induction system passage 39. Engine coolant is supplied to the hot spot 58 to heat the charge flowing through the auxiliary induction system, when desired.
In the embodiment of FIGS. 1 and 2, two alternately firing fuel injection nozzles were provided. In connection with that embodiment, one nozzle was disposed adjacent the manually positioned throttle valve and the other was positioned adjacent the automatically positioned control valve. It is to be understood that the invention is susceptible to use in engines having only one fuel injection nozzle for multiple cylinders. In conjunction with such an arrangement the single nozzle may be positioned as the nozzle 54 adjacent the manually positioned throttle valve 31 as shown in FIG. 3 or as the single nozzle 55 adjacent the automatically positioned control valve 33 as shown in FIG. 4.
The invention is also susceptible of application to engines in which a single fuel injection nozzle is provided for each chamber of the engine. Such an arrangement is shown in FIGS. 5 and 6 where, as has been previously noted, portions of the engine which are the same and function the same as in earlier described embodiments have been identified by the same reference numerals and will not be described again.
In conjunction with this embodiment, the primary difference between it and the previously described embodiments is in the intake manifold and fuel injection system. The control device 25 for the injection system is, however, the same in configuration and operation of the previously described embodiments. The associated controls, however, must be such so as to accommodate the fact that separate nozzles are provided for each chamber 18, as will become apparent.
The intake manifold of this embodiment is identified generally by the reference numeral 101 and includes an intake 102 to which air is delivered by the flexible conduit 28. A single manually positioned throttle valve 102 is supported in the inlet 102 on a shaft 104. As with the previously described embodiment, an idle air bypass 105 may be provided around the throttle valve 103 so as to introduce additional idle air flow.
Downstream of the throttle valve 103, the manifold 101 is provided with a plenum chamber 105. Runners 106 extend from the plenum 105 to each of the cylinder head intake passages 17. In accordance with this embodiment, a control valve 107 is positioned in each main intake runner 106. The control valves 107 are all affixed to a common shaft 108 and the position of the control valves 107 is controlled by a vacuum actuator 109 having an actuating rod 111 which is connected to the shaft 108 by means of a lever 112. The actuator 109 is operated by induction system vacuum, as in the previously described embodiment and a vacuum port 113 is provided for this purpose.
An auxiliary intake passage 114 is provided in the cylinder head 15 for each chamber 16. The cylinder head passages 114 terminate in auxiliary intake ports 115. As with the previously described embodiments, the ports 115 are juxtaposed to the main intake ports 18 of the cylinder head 15.
Each auxiliary intake passage 114 is formed with an enlarged mouth 116 formed in both the cylinder head 15 and intake manifold 101. Each mouth 116 is served by an inlet 117 that opens into the main intake runners 106 upstream of the control valves 107.
The auxiliary induction passages consisting of the inlet 117, mouth 116, passages 114 and ports 115 have an effective cross sectional area substantially less than that of the main induction passage for the reasons afore-described.
Disposed on the side of the runners 106 opposite to the auxiliary induction system inlets 117 are fuel injection nozzles 118, there being such a nozzle for each chamber 16. The nozzles 118 are dispositioned so that they will inject into the runners 106 toward the upstream closed edge of the throttle valves 107 and also into the auxiliary induction system inlets 117. In this way, condensation or the deposition of liquid fuel on the manifold passages will be eliminated. In all other regards this embodiment operates the same as the previously described embodiments and for that reason a detailed description of its operation will not be given.
It should be readily apparent that a number of embodiments of the invention have been described and each of which permits the use of fuel injection while minimizing low speed running problems, particularly those associated with the deposition of liquid fuel on the induction tract. Furthermore, in certain embodiments the cost of the system is reduced through the use of one fuel injection nozzle for a plurality of chambers. This is done in such a way that manifold wetting and unequal distribution is avoided even though the nozzle is at a considerable distance from the various chambers which it serves. Furthermore, the concept of providing alternately firing fuel nozzles has also been disclosed. Even though several embodiments of the invention have been illustrated and described, it is believed to be readily apparent that this invention is susceptible of use in still further embodiments without departing from the spirit and scope of the invention as defined by the appended claims. | Several embodiments of fuel injected internal combustion engines having improved injection and induction systems for improving performance, particularly at low speeds. In each embodiment, the injection nozzle is disposed in a position so as to have its discharge spray directed against a throttle valve of the engine so as to improve fuel vaporization at low engine speeds. In each embodiment, an auxiliary induction system is also provided having a relatively small cross sectional area. The idle and low load charge requirements of the engine are supplied through this auxiliary induction system to further improve vaporization and also to promote turbulence in the chamber at the time of combustion. The fuel injection nozzles of the embodiment are disposed so that their discharge spray either intercepts the inlet opening to the auxiliary induction system or is diverted by the throttle valve toward this opening. In one embodiment of the invention, two fuel injection nozzles are employed which discharge alternately. | 5 |
FIELD OF THE INVENTION
The invention relates generally to pressure transducers and specifically to output devices for pressure transducers.
BACKGROUND OF THE INVENTION
Pressure transducers are used for measuring the pressure of a fluid in a device or system. Pressure transducers may typically provide two types of outputs—(1) a cable connection for transmitting a signal representative of the sensed pressure to a remote monitoring or control device and (2) a human-readable display for providing a local reading of the sensed pressure.
Installation requirements for pressure transducers in the field may impose particular space or configuration requirements on the design of output devices for the pressure transducers. One use of a pressure transducer is to measure the pressure of a gas line. A pressure transducer is typically connected to a gas line such that it is perpendicular to the gas line. The connection between the pressure transducer and the gas line typically includes a passage for the fluid whose pressure is being measured, with a valve to an inlet to a sensing chamber in the transducer. When a pressure transducer is installed on a gas line, it is generally preferable that the passage provided in the connection be positioned so that it is parallel to the direction of flow in the gas line to avoid interruption of the flow. Accordingly, the position of the gas line will dictate the orientation of the pressure transducer. In many applications there are similar constraints on where a pressure transducer may be installed and how it may be positioned.
It is important that the cable connector and/or the display provided for output from a pressure transducer be accessible under various installation conditions. A local display should be oriented so that it is convenient and easy to read. A cable connector should be oriented so that it can easily be connected to the appropriate cable. When a pressure transducer is installed in the field, one or more sides of the pressure transducer may be obscured or obstructed, requiring the outputs to have particular orientations in order to be accessible. Limited vantage points might be available for viewing a display. In addition, under certain circumstances, a display having a particular orientation or a cable connector facing in a particular orientation may be especially desirable. It may be important for a number of displays to be aligned, for example, to form a “bank” of displays by positioning several transducers and their associated displays together on a set of gas lines. Given these requirements, pressure transducers having different configurations of cable connectors and local displays, particularly relative to the fluid passage of the pressure transducer, are generally needed for different applications. To satisfy this need, manufacturers have typically provided each type of transducer in several different configurations, each configuration having a unique placement, or orientation, of the display. However, carrying inventory for multiple configurations of the same transducer is expensive.
A measuring indicator device for a pressure transducer is disclosed in U.S. Pat. No. 6,119,524, entitled “Measuring Indicator Device,” issued Sep. 19, 2000, to Kobold. The display disclosed in the '524 patent is screwed onto a casing. A pressure transducer and a line socket are connected on opposite sides of the casing. The casing is rotatable around its longitudinal axis. The position of the display can be adjusted by rotating the casing. Although the position of the display disclosed in the '524 patent may be adjusted, the disclosed design does not eliminate the need for providing multiple configurations of the same transducer. For example, FIGS. 1 and 2 of the '524 patent show two such configurations in which the display has been screwed into the casing at two different orientations which are rotated ninety degrees from one another.
An adaptable, easily adjustable output device for pressure transducers is needed.
SUMMARY OF THE INVENTION
The present invention is directed to an adjustable output device for pressure transducers and a method for installing and adjusting the output device. An output device constructed in accordance with the present invention may be field-configured in a multitude of ways, largely eliminating the need for preselecting particular output devices for particular installations. An output device constructed in accordance with the invention incorporates a cable connector and an electronic display. In one aspect of the invention, both the cable connector and the electronic display can be selectably positioned relative to the pressure transducer.
In one aspect of the invention, the orientation of the electronic display relative to the cable connector is adjustable. The electronic display is adjustable such that the digits of the display can generally be viewed right-side up or in the orientation most convenient to the user, given the constraints of a particular installation. The electronic display is rotatable around an axis perpendicular to the plane of the display. In some embodiments of the invention, the output device is substantially cylindrical in form. One end of the output device connects to a pressure transducer. The electronic display is disposed on the opposite end of the output device. In some embodiments, the display is disposed transverse to the longitudinal axis of the output device so that it can be seen from above, e.g., by forming an endcap for a generally cylindrical output device. The display can be rotated around the longitudinal axis of the output device in some embodiments. The orientation of the display can be adjusted without the use of tools and without taking apart the device or removing mechanical fasteners such as screws.
In another aspect of the invention, the orientation of the cable connector relative to the pressure transducer is adjustable. In one aspect of the invention, the output device may connect to the pressure transducer in a number of orientations. The orientation of the output device relative to the pressure transducer selects the orientation of the cable connector. In some embodiments, the cable connector is positioned on the side of the output device. The position of the output device may be changed without the use of tools. In some embodiments, the adjustability of the output device is provided through a bayonet connection between the output device and the pressure transducer.
These and other features and advantages of the present invention will become readily apparent from the following detailed description, wherein embodiments of the invention are shown and described by way of illustration of the best mode of the invention. As will be realized, the invention is capable of other and different embodiments and its several details may be capable of modifications in various respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not in a restrictive or limiting sense, with the scope of the application being indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the present invention, reference should be made to the following detailed description taken in connection with the accompanying drawings, wherein:
FIG. 1 is a side view of a pressure transducer assembly including an output device constructed in accordance with one embodiment of the invention;
FIG. 2 is a side view of the pressure transducer assembly of FIG. 1;
FIG. 3 is a side view of the output device of FIG. 1;
FIG. 4 is a top view of the output device of FIG. 3; and
FIG. 5 is a cross-sectional view of the output device of FIG. 3, taken along the lines A—A indicated in FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 show one example of an output device 30 constructed according to the invention. As shown, output device 30 is coupled to a pressure transducer 20 . Transducer 20 and output device 30 form at least part of a transducer assembly 10 . The output device 30 is designed to provide a conveniently adjustable output mechanism for pressure transducer 20 that is usable in a range of installation situations. Output device 30 includes a housing 31 , an electronic display 40 , and a cable connector 50 . An electrical signal representing the pressure measurement taken by the pressure transducer 20 is provided through the output device 30 for local display on electronic display 40 and for remote use through cable connector 50 . The output device 30 allows both the orientation of the cable connector 50 relative to the pressure transducer 20 and the orientation of the electronic display 40 to be adjusted.
The electronic display 40 is rotatably connected to the housing 31 so that the display 40 can be rotated relative to housing 31 about an axis perpendicular to the plane of the display 40 . Preferably, the two types of outputs 40 , 50 provided through the output device 30 both have a range of positions and may be adjusted independently, allowing a virtually infinite number of configurations to be implemented using the output device of the present invention.
In certain embodiments, the basic shape of the output device 30 is designed to match the dimensions and form of the pressure transducer 20 . The pressure transducer 20 may be cylindrical in form, as illustrated in FIGS. 1 and 2. FIGS. 3, 4 and 5 are illustrations of the output device 30 , shown detached from the pressure transducer 20 . In the illustrated embodiment, the output device 30 is also substantially cylindrical in form. Housing 31 has a first end 33 , a sidewall 34 and a second end 35 , and housing 31 extends along a longitudinal axis 32 .
In the illustrated embodiment, the electronic display 40 is mounted on one end of the housing 31 . The cable connector 50 is mounted on the sidewall 34 . On its other end 35 , the housing 31 connects to the pressure transducer 20 with a pressure transducer connection 60 . In the illustrated embodiment, the output device 30 attaches to the top of a pressure transducer 20 , on the end opposite to the pressure transducer's fluid inlet, such that the output device 30 and pressure transducer 20 are coaxial along the longitudinal axis 32 . The circular cross-sections of the output device 20 and the pressure transducer 20 may have substantially the same dimensions. This arrangement allows the entire pressure transducer assembly 10 to have a compact and integrated profile.
In the illustrated embodiment, the electronic display 40 is provided on the end 33 of the housing 31 that is opposite to the pressure transducer connection 60 , such that it forms an endcap for the top of the output device 30 . The display 40 is substantially planar and is disposed so that it is transverse to the longitudinal axis 32 . In particular, in the illustrated embodiment, the display is disposed so that it is perpendicular to the longitudinal axis 32 of the housing 31 . The positioning of the display 40 allows it to be viewed from above the pressure transducer assembly 10 , e.g., looking toward the output device along the longitudinal axis 32 of the housing 31 . This is especially convenient when the installation of the pressure transducer assembly is underground, low to the ground, or obscured from the side. The display 40 is disposed so that it may be rotated relative to the housing 31 around an axis perpendicular to the face of the display 40 . In the illustrated embodiment, the display 40 is perpendicular to the longitudinal axis 32 of the housing 31 and can be rotated around the longitudinal axis 32 . The rotatability of the display 40 allows the display 40 to be adjusted so that it may be read in the desired or most convenient orientation. One advantage is a reduction in the risk of human error in reading the displayed pressure measurement.
The face of the display 40 in accordance with some embodiments of the invention is shown in FIG. 4 . In the illustrated embodiment, the top of the housing 31 includes a bezel 44 with the electronic display 40 disposed in the bezel 44 . In some embodiments, the display 40 can be rotated up to about 360 degrees around the axis 32 . The display 40 may be rotatable continuously or in small increments through its range of rotation. In some embodiments, the display 40 may be adjusted by holding the bezel 44 and rotating it, without the use of tools. The bezel 44 may have a textured, e.g., ridged, surface to allow for ease of gripping for rotating the bezel. Since the display 40 is rotatable with respect to housing 31 , the orientation of display 40 may be adjusted without manipulating the connection of the output device 30 to the pressure transducer 20 .
As noted above, display 40 is rotatably coupled to housing 31 . That rotatable coupling may be provided using a variety of mechanisms, such as friction connections, grip ring, or ratchet-type connections. A single mechanism can provide both attachment of the display 40 to the housing 31 and rotation of the display 40 . As may be seen in the cross-sectional view of FIG. 5, in some embodiments, the upper portion of the housing 31 may form a detachable electronic display unit 42 . The electronic display unit 42 incorporates the electronic display 40 , the bezel 44 , and a display electronics assembly housing 46 for a display electronics assembly 47 that generates and controls the electronic display 40 . In the illustrated embodiment, the electronic display unit 42 has a grip ring 48 at its base. The grip ring 48 is friction fitted to the inner sidewall 37 of the main portion of the housing 31 . The grip ring 48 frictionally couples the electronic display unit 42 to the main portion of the housing 31 and permits the unit 42 to be rotated relative to housing 31 about the longitudinal axis 32 . A detent disposed on the inner sidewall 37 of the housing 31 can prevent hyperrotation of the display 40 to avoid, for example, twisting the wires that connect to the display electronics assembly 47 sufficiently to damage the wires or break one of their electrical connections. The electronic display unit 42 may be replaced by a blank endcap if a local display is not desired for a particular installation.
The electrical connections inside the output device can be seen in the cross-section of FIG. 5 . The electronic display 40 may be any type of electronic display, such as an LCD display or an LED display, including a loop-controlled or a voltage-controlled LED display. The display electronics assembly 47 receives a signal representative of the sensed pressure from the pressure transducer through wires 49 and generates the reading seen in the electronic display 40 . The display electronics assembly 47 may include a microprocessor and may allow for calibration, and other adjustments, such as the units of measurement used in the display, of the electronic display 40 . The electronic display 40 may include a control panel to allow for field adjustment of the electronic display 40 .
In the illustrated embodiment, the cable connector 50 is mounted to the sidewall 34 of the housing 31 . Although, in the illustrated embodiment, cable connector 50 is a sub-D connector, any desired type of cable connector 50 , standard or custom-designed, may be used. The position of the cable connector 50 relative to the pressure transducer can be adjusted by rotating the housing 31 around the longitudinal axis 32 relative to the pressure transducer 20 so that the cable connector 50 has the desired direction.
In certain embodiments, the housing 31 of the output device 30 is dimensioned both to match the dimensions of the pressure transducer and to accommodate the cable connector 50 in the desired orientation. Cable connector 50 includes a face 52 and a mounting plate 54 . The cable connector 50 may be mounted so that the face 52 of the connector 50 does not protrude from the sidewall 34 of the housing 31 . In the illustrated embodiment, the cable connector 50 is mounted in a recess 36 in the sidewall 34 of the housing 31 to preserve the substantially cylindrical and compact shape of the housing 3 1 . The recess 36 is built into the housing 31 to accommodate the depth 56 of the cable connector 50 and has a flat back wall for attachment of the mounting plate 54 of the cable connector 50 . Although the cable connector 50 could be affixed to the housing 31 in a number of orientations, the cable connector 50 is preferably oriented with its longest dimension either along the longitudinal axis (a vertical orientation) or perpendicular to the longitudinal axis (a horizontal orientation). The longest dimension of the illustrated cable connector 50 is its width 55 . Attaching the cable connector 50 in a vertical orientation may disadvantageously require the length of the output device 30 along the axis 32 to be extended. The cable connector 50 shown is mounted with a horizontal orientation. However, in the illustrated embodiment, because the housing 31 is dimensioned to match the pressure transducer 30 , the diameter 39 of the housing 31 is not wide enough to accommodate the width 55 of the cable connector 50 . Accordingly, two protrusions 38 extend from the sidewall 34 of the housing 31 , adjacent to the back wall of the recess 36 , to support the mounting plate 54 of the cable connector 50 without substantially altering the cylindrical profile of the housing 31 , as can be seen in FIGS. 2 and 3. Depending on the characteristics of the connector used for particular embodiments, the housing 31 may be appropriately dimensioned to provide the desired positioning for the connector. The cable connector 50 may be attached to the housing 31 by mechanical or adhesive means, for example, screws or glue. An aperture is provided in the recess 36 of the housing 31 to allow for electrical wires or leads to attach to the back of the cable connector 50 inside the housing 31 . In the illustrated embodiment, the cable connector 50 receives a signal representative of the sensed pressure from the pressure transducer through wires 59 , which can be seen in FIG. 5 . The wires 49 , 59 to the display electronics assembly 47 and to the cable connector 50 may also be used, for example, to supply power and send and receive other signals, which may, for example, be generated by front end electronics, from the pressure transducer 20 .
In some embodiments, the housing 31 selectably and detachably connects to pressure transducer 20 at its bottom end 35 . As shown in FIG. 3, the end 35 may be implemented as a bayonet type connector 60 , which defines one or more slots 62 for facilitating a bayonet connection between end 35 and transducer 20 . In such embodiments, posts in transducer 20 (not shown) engage slots 62 in a known fashion to selectably couple or release output device 30 and transducer 20 . In the illustrated embodiment, bayonet connector 60 defines four slots 62 (only one of which is shown in FIG. 3) and the slots are evenly spaced apart from one another (or spaced at 90 degree intervals) around end 35 . In this embodiment, the output device 30 may be connected to transducer 20 in any one of four different orientations (i.e., each of the orientations being rotated by 90 degrees from another one of the possible orientations).
In this embodiment, the orientation of cable connector 50 with respect to transducer 20 may be selected simply by coupling the posts of transducer 20 into the appropriate slots 62 of bayonet connector 60 . If it is desired, for example, to rotate the position of cable connector 50 by ninety degrees, the output connector 30 may simply be detached from transducer 20 , rotated ninety degrees, and then reattached via the bayonet connector. It will be appreciated that additional flexibility in selecting the orientation of cable connector 50 may be provided if desired by adding additional slots 62 to bayonet connector 60 (e.g., six slots may be provided with all slots being spaced apart by sixty degrees). The bayonet connection is readily field-adjustable without the use of tools. Once the cable connector 50 has been located in a desired orientation, the electronic display 40 can be independently adjusted, or rotated, to obtain the desired orientation.
The illustrated embodiment provides two-degrees of freedom for adjusting the configuration of an output device for a pressure transducer. Because both the cable connector 50 and the local display 40 are readily adjustable, the output device 30 may be readily adapted to a multitude of installation situations.
An output device constructed in accordance with the present invention may be combined with pressure transducers of any type. The display may be disposed so that it is transverse but not perpendicular to the longitudinal axis of the output device. Although the illustrated embodiment incorporates and is designed to accommodate a sub-D cable connector, embodiments of the present invention could also be constructed using any type of cable connector. Other types of connections, including other type of bayonet connections, for the output device or other types of connections for the electronic display may be used in alternate embodiments. While the present invention has been illustrated and described with reference to particular embodiments thereof, it will be apparent that modifications can be made and the invention can be practiced in other environments without departing from the spirit and scope of the invention, set forth in the accompanying claims. | An output device for a pressure transducer incorporates a cable connector and an electronic display. Both may be selectably positioned relative to the pressure transducer. In one aspect of the invention, the electronic display is rotatable around an axis perpendicular to the plane of the display. In another aspect of the invention, the cable connector is positioned by adjusting the connection of the output device relative to the pressure transducer. In some embodiments, the adjustability of the output device is provided through a bayonet connection between the output device and the pressure transducer. The adjustments to position of the display and of the cable connector may be performed without the use of tools. An output device constructed in accordance with the present invention may be field-configured in a multitude of ways, largely eliminating the need for the preselection of particular output devices for particular installations. | 6 |
This application is a continuation-in-part of application Ser. No. 08/540,280 filed on Oct. 06, 1995, now abandoned.
RELATED APPLICATION
This application is related to applications U.S. Ser. No.: 08/412,474, filed Mar. 28, 1995 entitled "Valve Control System" and U.S. Ser. No.: 08/452,232, filed May 26, 1995 entitled "Multiple Rocker Arm Valve Control System" assigned to the same assignee, Eaton Corporation, as this application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a valve operating apparatus for an internal combustion engine and, more specifically, to apparatus to cause the engine valve to operate or not to operate depending on the energization state of a solenoid actuator.
2. Description of the Prior Art
Variable valve control systems for multiple valve engines wherein the intake and/or exhaust valves can either be selectively actuated or actuated at selected lift profiles, are well known in the art. Example systems are shown in U.S. Pat. Nos. 4,151,817 and 4,203,397 the disclosures of which are hereby incorporated by reference except those portions which also incorporate by reference. U.S. Pat. No. 4,151,817 discloses a primary rocker arm element engageable with a first cam profile, a secondary rocker arm element engageable with a second cam profile, and means to interconnect or latch the primary and secondary arm elements. U.S. Pat. No. 4,203,397 discloses an apparatus to selectively engage or disengage an engine poppet valve so as to connect or disconnect the valve from the rest of the valve gear using a latch mechanism thereby causing the valve to operate or remain stationary.
A particular problem exists in prior art systems which operate a valve train which incorporates hydraulic lash adjusters in that means must be provided to prevent the lash adjuster from overly expanding or "pumping up" when the valve is in its inactive mode and there is essentially no resisting force applied by the valve spring. In prior art systems it has been necessary to provide an auxiliary contact surface on the rocker arm structure which is maintained in engagement with a base circle cam portion formed on the camshaft to prevent the lash adjuster from overly expanding.
Prior art methods and mechanisms tend to be slow in response, bulky, expensive and have high actuation force and are unreliable. Selective valve actuation systems are designed to selectively engage intake and/or exhaust valves to better match the power output of an engine for a motor vehicle to the load for improved efficiency and fuel economy.
SUMMARY OF THE INVENTION
The present invention overcomes the limitations of the prior art by disclosing a valve gear rocker arm which has a selectively latchable rocker arm section that can be disengaged to render the engine poppet valve inoperative or the latchable rocker arm section can be engaged thereby allowing the valve train to operate in a traditional manner.
The present invention discloses a means to solve the hydraulic lifter pump up problem by providing a latchable rocker arm assembly including an inner rocker arm having a roller which contacts the cam; an outer rocker arm which engages the valve, the inner and outer arms being in nesting relation to one another and in pivotal contact with the output plunger of a stationary lash adjuster; and a sliding latch member which is moveable between an active position wherein the inner and outer arms are effectively latched together and operable to actuate the valve, and an inactive position wherein the inner and outer arms are free to move relative to one another and the valve is not actuated. The assembly further includes a biasing spring acting between the inner and outer arms to bias the inner arm into engagement with the cam and into engagement with the plunger of the lash adjuster while the outer arm is engaged with the engine poppet valve. The nested relationship between the inner and outer arms is effective to counteract the plunger spring force to insure that the lash adjuster does not pump up when the rocker arms are in their unlatched condition.
A new type of sliding latch member is disclosed which is slidingly supported on the outer rocker arm which controls the activation of the engine poppet valve by sliding into and out of engagement with the inner rocker arm thereby connecting the inner and outer rocker arms. Contact shoes are formed on the latch member and provide a contact surface against which a pivoted arm (bellcrank) operates to cause the sliding latch member to move against a latch return spring when the camshaft in the base circle position so as to unload the valve train. The bellcrank is moved by means of an electromagnetic solenoid which is powered by a control unit. In this manner, an engine popper valve can be activated or deactivated by a signal from the control unit to optimize engine operations to improve fuel economy and/or emissions.
If the solenoid is energized and the latch member cannot be moved because the cam is not in a base circle position and the valve train is loaded, then a lost motion spring device positioned on an actuator shaft is compressed so that when the valve train unloads, the spring device causes the pivoted arm to move the latch member to deactivate the engine poppet valve.
Other objects and advantages of the invention will be apparent from the following description when considered in connection with the accompanying drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view of the engine poppet valve control system of the present invention installed in a valve train;
FIG. 2 is a cross sectional view of the actuator and an alternate embodiment of the bellcrank of the present invention;
FIG, 3 is a partial perspective view of the rocker arm assembly of the present invention;
FIG. 4 is a plan view of the rocker arm assembly of the present invention;
FIG. 5 is a front elevational view of the rocker arm assembly of FIG. 4;
FIG. 6 is an elevational view of the actuator and rocker arm assembly of the present invention;
FIG. 7 is a front elevational view of the outer rocker arm of the present invention;
FIG. 8 is a sectional view of the outer rocker arm taken along line VIII--VIII of FIG. 7;
FIG. 9 is a sectional view of the outer rocker arm taken along line IX--IX of FIG. 7;
FIG. 10 is a plan view of the inner rocker arm of the present invention;
FIG. 11 is a top elevational view of the inner rocker arm of FIG. 10;
FIG. 12 is an end elevational view of the inner rocker arm of FIG. 10;
FIG. 13 is a sectional view of the inner rocker arm of FIG. 10 taken along line XIII--XIII;
FIG. 14 is a plan view of the latch member of the present invention;
FIG. 15 is a top elevational view of the latch member of FIG. 14;
FIG. 16 is a plan view of the return spring of the present invention;
FIG. 17 is a top elevational view of the return spring of FIG. 16.
FIG. 18 is a cross-sectional view of the link pin of the present invention;
FIG. 19 is an end view of the link pin of the present invention; and
FIG. 20 is a partial cross-sectional view of the inner rocker arm supported on the link pin and the plunger of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Now referring to FIG. 1 of the drawings, a cross-sectional view of the engine poppet valve control system 2 of the present invention installed as part of the valve train on an internal combustion engine is shown. A portion of an engine cylinder head 10 of an internal combustion engine of the overhead cam type is shown along with the camshaft 4, the hydraulic lash adjuster 5, the engine poppet valve 6, the valve spring 7 and the valve cover 8.
As illustrated herein, the engine poppet valve control system 2 is of the type which is particularly adapted to selectively activate or deactivate an engine poppet valve 6 and comprises a rocker arm assembly 14 which is shiftable between an active mode wherein it is operable to open the engine poppet valve 6, and an inactive mode wherein the valve is not opened; and an actuator assembly 16 which is operable to shift the rocker arm assembly 14 between its active and inactive modes through a bellcrank 44.
The rocker arm assembly 14 comprises an inner rocker arm 18 which is engageable with the valve actuating camshaft 4 at the cam lobe 20 supported on the cam base shaft 23 and the cylinder head 10 of the engine, an outer rocker arm 22 which is engageable with an engine poppet valve 6 which is maintained normally closed by a valve spring 7, a biasing spring 26 acting between the inner and outer rocker arms 18 and 22 to bias the inner rocker arm 18 into engagement with the camshaft 4 through the roller follower 24 and the outer rocker arm 22 into engagement with the plunger 30 which rides in the main body 32 of lash adjuster 5. The construction and the function of the lash adjuster 5 are well known in the art and will not be described in detail herein. The biasing spring 26 applies sufficient force to the plunger 30 to keep the lash adjuster 5 operating in its normal range of operation at all times.
A latch member 28 is slidably received on the outer rocker arm 22 and biased into a "latched" condition by latch spring 29, the latch member 28 is effective to latch the inner and outer rocker arms 18 and 22 so that they rotate together to define the active mode of the engine poppet valve control system 2 of the present invention or to unlatch them where the inner and outer rocker arms 18 and 22 are free to rotate relative one to the other to define the inactive mode. A link pin 33 passes through coaxial apertures formed in the outer rocker arm 22 and through an elongated link pin aperture 21 formed in the latch member 28 and provides a pivotal support to the outer rocker arm 22 where the inner rocker arm 18 pivots on the link pin 33 which in turn pivots on lash adjuster 5. In the preferred embodiment of the invention, the inner rocker arm 18 is pivotally mounted on link pin 33 and the outer rocker arm 22 pivotally engages the link pin 33 which supports the inner rocker arm 18 and indirectly by the plunger 30 of the lash adjuster 5. The link pin 33 passes through coaxial apertures 61A and 61B formed in the outer rocker arm (see FIG. 11) and through a link pin aperture 21 formed in the latch member 28 and provides pivotal support to the outer rocker arm 22 where the link pin 33 pivots on the plunger 30. In the preferred embodiment of the invention, the inner rocker arm 18 is pivotally supported on the link pin 33 and the outer rocker arm 22 is nonrotatably mounted on link pin 33 where the link pin 33 is pivotally supported by plunger 30 of lash adjuster 5. In other words, the link pin 33 holds the inner and outer rocker arms 18 and 22 and the latch member 28 in the proper orientation while allowing relative rotation between the inner and outer rocker arms 18 and 22, and axial motion of the latch member 28 due to the elongated link pin aperture 21 formed in both sides of latch member 28. The link pin 33 extends through the latch member 28 and the outer rocker arm 22 while the inner rocker arm 18 pivots on link pin 33 at the saddle portion 50 (see FIGS. 8, 18-20) and retains the inner rocker arm 18 and the outer rocker arm 22 and the latch member 28.
The outer rocker arm 22 is an elongated rectangular structure having opposed side walls, and a first end 22A for engaging a biasing spring 26 and a second end 22B having a valve engagement surface 22C formed thereon. The valve engagement surface 22C is in contact with the engine poppet valve 6. The inner rocker arm 18 is an elongated rectangular structure received between the opposed side walls of the outer rocker arm 22 (see FIG. 3). The inner rocker arm has a contact surface 18A formed thereon engageable with the latch member 28 when the rocker arm assembly 14 is in the normal active mode.
A nonenergized electromagnetic actuator assembly 16 allows the latch spring 29 to force the latch member 28 into a position to provide actuation of the engine poppet valve 5 by the camshaft 4 through the rocker arm assembly 14 known as the active mode. When energized by the control unit 51, the actuator assembly 16 applies a spring force to the bellcrank 44 through actuator spring 39 thereby forcing the latch member 28 into a position to provide for a loss motion between the inner and outer rocker arm 18 and 22 so that there is no mechanical actuation of the engine poppet valve 6 by the camshaft 4 known as the inactive mode as shown in FIG. 1.
The actuator assembly 16 consists of a circular armature 35 which is electromagnetically attracted toward the electromagnet 37 when an electrical current is supplied to the coil 27 by the control unit 51. The circular armature 35 is attached to an armature shaft 38 which is connected to a bellcrank 44 through a compression actuator spring 39. The actuator spring 39 pilots on the armature shaft 38 and is retained in a static position on the armature shaft 38 by retainers 40 and 43 where retainer 40 is secured to the armature shaft 38 and retainer 43 is free to slide along the armature shaft 38 while contacting the bellcrank 44 so as to apply a pushing force against the bellcrank 44 when the actuator assembly 16 is energized and the armature 35 contacts the electromagnet 37. In this manner, if the latch member 28 is vertically loaded by a clamping force generated by the inner and outer rocker arms 18 and 22 and unable to be moved into an inactive mode upon energization of the electromagnet 37, the electromagnet 37 can simply load the actuator spring 39 which provides for lost motion between the actuator 16 and the bellcrank 44 and forces the bellcrank 44 against the latch member 28. Thus, the armature 35 moves to contact the electromagnet 37 and the retainer 40 moves to compress the actuator spring 39 and apply a preload force against the bellcrank 44 through the retainer 43. As soon as the latch member 28 becomes unloaded, the preloaded actuator spring 39 forces it into a position so that the rocker arm assembly 14 is in the inactive mode. The bellcrank 44 pivots on arm pin 46 and is secured to the armature shaft 38 by retention plug 42. The bellcrank 44 contacts the latch member 28 at latch shoes 31 which are formed as part of the latch member 28 where the contact mechanism is biased toward a position to activate the engine poppet valve 6 (active mode) by the latch spring 29 which acts upon the latch shoe 31 and is secured at one end through holes formed in the link pin 33.
The biasing spring 26 is preloaded to maintain a load between the roller follower 24 rotating on roller pin 25 and the camshaft 4 sufficient to keep the lash adjuster 5 operating in its normal range of adjustment. Changes in the preload on the biasing spring 26 can be made by changing the position of the preload adjuster 47.
FIG. 1 illustrates the valve control system 2 in an inactive position where the actuator assembly 16 is energized and the armature 35 is magnetically attracted and moved to come in contact with the electromagnet 37. Armature shaft 38 acts against the actuator spring 39 pushing against the bellcrank 44 which in turn pushes against both latch shoes 31. If the rocker arm assembly is in an unloaded condition where the cam lobe 20 is contacting the roller follower 24 on the base circle, than the latch member 28 is moved against latch spring 29 so as to cause the inner rocker arm assembly 18 to become disconnected from the outer rocker arm assembly 22 so that the engine poppet valve 6 remains closed (i.e. inactive mode).
The bellcrank 44 acts as a bellcrank mechanism pivoted at one end where a pivot 45 rotating at arm pin 46 is used to translate motion supplied by an actuator to the rocker arm assembly 14. In this manner, the travel of the actuator does not have to match that required by the latch member 28 of rocker arm assembly 14 and an actuator with a low displacement can be used to supply the required motion to the latch member 28 using the bellcrank 44 to amplify the displacement.
Now referring to FIG. 2, an alternative embodiment bellcrank 44' is shown where a pivot 45' has been moved to be positioned between the actuator armature shaft 38 and the latch member 28. The bellcrank arm 44A is shorter than the bellcrank arm 44B to provide for travel amplification of the actuator assembly 16 in the same proportion as the ratio of the length of bellcrank arm 44B to the length of bellcrank arm 44A. Thus, using the present invention, an actuator with high force capability but low travel can be used to provide the travel required by the latch member 28 to shift the rocker arm assembly 14 from an active to an inactive position. The actuator assembly 16 is shown as an electromagnetic solenoid having a coil 27 and a armature 35 and actuator shaft 38. Other types of actuators could be used in conjunction with the bellcrank 44 to move the latch member 28 to change the operational status of the engine poppet valve 6. For example, hydraulic or pneumatic powered actuators could be used to supply the required force input to the bellcrank 44.
Reference to FIG. 3 is now made to provide a better understanding of the operation of the rocker arm assembly 14. The perspective view of the rocker arm assembly 14 as shown in FIG. 3 illustrates the inner rocker arm 18 surrounded by the outer arm 22 where the inner rocker arm 18 contacts and pivots on the lash adjuster 5 (see FIG. 1) while the outer rocker arm 22 contacts and actuates the engine poppet valve 5 when the latch member 28 is in the active position. The cam roller follower 24 rotates on roller pin 25 which is supported in the inner rocker arm 18. The latch member 28 is biased into the active position by the latch spring 29 which is compressed to act to press against the latch shoes 31 which are formed as part of the latch member 28.
The two ends of latch spring 29 engage a hole formed at each end of the link pin 33 respectively and retain the latch spring 29 in place. The link pin 33 also holds the inner and outer rocker arms 18 and 22 and the latch member 28 in the proper orientation while allowing relative rotation between the inner and outer rocker arms 18 and 22, and axial motion of the latch member 28 due to the elongated link pin aperture 21 formed in both sides of latch member 28. The link pin 33 extends through the latch member 28 and the outer rocker arm 22 and the inner rocker arm 18 and retains the latch spring 29 on both sides of the latch member 28.
The latch member 28 has an contact plate 41, the position of which determines when the rocker arm assembly 14 is in an active or inactive mode. When the latch member 28 is moved toward the inner rocker arm 18, the rocker arm assembly 14 is in the active mode and the latch member 28 provides a mechanical link between the inner and outer rocker arms 18 and 22 to open the engine poppet valve 6 in response to the camshaft 4 acting on the roller follower 24. When the latch member 28 is moved away from the inner rocker arm 18, the rocker arm assembly 14 is placed in an inactive mode where the inner arm 18 is not linked to the outer arm 22 and the engine poppet valve 6 is closed. As the contact plate 41, as part of the latch member 28, is moved toward the inner rocker arm 18, the contact plate 41 catches an edge of the inner rocker arm 18 and thereby mechanically links the inner and outer rocker arms 18 and 22 causing the engine poppet valve 6 to open and close in response to the cam lobe 20. As the contact plate 41 is moved away from the inner rocker arm 18, the inner rocker arm 18 no longer contacts the contact plate 41 and the inner rocker arm 18 moves in response to the camshaft 4 but its motion is not transferred to the outer rocker arm 22 or the engine poppet valve 6. When the rocker arm assembly is in the inactive mode, the inner rocker arm 18 pivots on the lash adjuster 5 at the plunger 30 and compresses the biasing spring 26 which is supported at one end by the inner rocker arm 18 and at a second end by the outer rocker arm 22. Thus, the biasing spring 26 functions to maintain contact between the cam roller follower 24 and the cam lobe 20 and to provide the proper compression load on the lash adjuster 5. The initial preload on the biasing spring 26 can be changed with the preload adjuster 47.
Now referring to FIGS. 4 and 5, both top and end views of the rocker arm assembly 14 of the present invention are shown. The inner rocker arm 18 is generally surrounded by the outer rocker arm 22 where the latch member 28 is moved to cause the contact plate 41 to contact the inner rocker arm 18 for activation of the engine poppet valve 6 (active mode) or to not contact the inner rocker arm 18 for decoupling of the inner rocker arm 18 from the outer rocker arm 22 and deactivation of the engine poppet valve 6 (inactive mode). The latch spring 29 contacts the latch shoes 31, one formed on each side, and provides a spring bias to move the latch member 28 and specifically the contact plate 41 toward the inner rocker arm 18. Thus, the latch member 28 is spring biased toward the active mode. FIG. 5 clearly shows the functioning of the preload adjuster 47 which moves the lower spring support 43 of the inner rocker arm 18 away from or closer to the outer rocker arm 22, thereby altering the preload on biasing spring 26 and the force on the roller follower 24 against the cam lobe 20. The biasing spring 26 is held between the lower spring support 43 which is part of the inner rocker arm 18 and the outer rocker arm 22.
FIG. 6 is an end view of the actuator assembly 16 connected to the rocker arm assembly 14 of the present invention. The armature 35 is shown circular in shape although a variety of shapes and configurations could be utilized as practiced in the solenoid art. Any type of actuator that responds to an electrical command signal could be used to move the bellcrank 44 as pivoted on pivot 45 and arm pin 46 toward and away from the latch shoes 31 so as to activate or deactivate the rocker arm assembly 14. Separate actuators could be used, one for each of the latch shoes 31.
As described previously, the armature 35 is magnetically attracted to the electromagnet 37 when the coil 27 is energized by the contact plate 41. The armature 35 is connected to a armature shaft 38 which pushes against the actuator spring 39 through the retainer 40 which is attached to the armature shaft 38. In this manner, when the latch member 28 cannot be moved due to the clamping forces generated when the cam lobe 20 is opening the engine valve 6 between the inner and outer rocker arm 18 and 22 on the contact plate 41, the latch member 28 is preloaded by the actuator spring 39, which has been compressed against the bellcrank 44, to move the rocker arm assembly 14 into an inactive mode as soon as the roller follower 24 encounters the base circle of the camshaft 4. Likewise, the camshaft 4 must be rotated such that the cam roller follower is on the base circle for the rocker arm assembly 14 to be shifted into the active mode since the latch member 28 must be moved so that the contact plate 41 is positioned to engage both the inner and outer rocker arm 18 and 22.
FIG. 7 is an elevational view of the inner rocker arm 18 of the present invention. The inner rocker arm 18 consists of two side walls 53, 54 and a web portion 52 connecting the side walls 53, 54. The lower spring support 43 is attached and formed as part of the web portion 52.
FIG. 8 is a cross-sectional view of the inner rocker arm 18 of FIG. 7 taken along line VIII--VIII. The web portion 52 of the inner rocker arm 18 is shown having an oil drain 49 formed in a location coinciding with the area of the inner rocker arm 18 that contacts and pivots on the plunger 30 (see FIG. 1). A pin aperture 55 is formed in both of the side walls 53 and 54 to provide for support of the roller pin 25. A saddle portion 50 contacts and pivots on the link pin 33 which in turn contacts and pivots on the plunger 30. An end portion 58 contacts the contact plate 41 (see FIG. 2) at contact surface 18A when the rocker arm assembly 14 is in the active mode (actuator assembly 16 is not energized and the latch spring 29 moves the latch member 28 into engagement).
FIG. 9 is a cross-sectional view of the inner rocker arm 18 of FIG. 7 taken along line IX--IX. The web portion 52 extends to form the lower spring support 43 on which the biasing spring 26 rides. Also the preload adjuster 47 contacts the side of the lower spring support 43 opposite to that of the biasing spring 26 to provide for adjustment of the relative length between the inner rocker arm 18 and the outer rocker arm 22 where the biasing spring 26 is mounted thereby altering the preload on the biasing spring 26.
Referring now to FIGS. 10-13, various views of the outer rocker arm 22 of the present invention are shown. FIG. 10 is a side elevational view of the outer rocker arm 22 where a link pin aperture 61B is formed in both side walls 67 and 68 to provide support for the link pin 33. At the first end 22A of the outer rocker arm 22, an upper spring support 57 is formed which, in conjunction with the lower spring support 43 found in the inner rocker arm 18 provides a secure mounting arrangement for the biasing spring 26. Thus, the biasing spring 26 provides a separation force between the inner and outer rocker arms 18 and 22 and forces the roller follower 24 into contact with the cam lobe 20 and loads the plunger 30 of the lash adjuster 5. A valve contact pad 59 is provided at the second end 22B of the outer rocker arm 22 for contacting the top of the valve stem of engine poppet valve 6 at valve engagement surface 22C.
FIG. 11 is a top view of the outer rocker arm 22 of FIG. 10 more clearly showing the side walls 67 and 68 and both link pin apertures 61A and 61B. FIG. 12 in an end view of the outer rocker arm 22 of FIG. 10 more clearly showing the valve contact pad 59 which contacts the end of the engine poppet valve 6 at the valve engagement surface 22C thereby transferring the motion provided by the camshaft 4 and the inner rocker arm 18 to the engine poppet valve 6 when the rocker arm assembly 14 is in an active mode. It also illustrates how the side wall 68 is formed to provide a support portion 69 for the preload adjuster 47 (see FIGS. 1 and 5). FIG. 13 is a cross-sectional view of the outer rocker arm 22 of FIG. 10 taken along line XIII--XIII. FIG. 13 shows how the support portion 69 extends to provide a provision for the retention of the preload adjuster 47. The adjuster opening 70, formed in the support portion 69 can be drilled and tapped to provide the required method of retention. Note that only the side wall 68 is shown since the side wall side wall 67 does not extend to the area of the preload adjuster 47.
FIG. 14 is an elevational view of the latch member 28 of the present invention showing the contact plate 41 and one of the latch shoes 31A. A link pin aperture 21 allows the link pin 33 to extend therethrough and provides a location function to the latch member 28. The link pin aperture 21 is elongated to provide clearance for the movement of the latch member 28 to the active and inactive positions. FIG. 15 is a top view of the latch member 28 of FIG. 14 showing the side walls 73 and 75 which are joined at one end to form the contact plate 41 and their opposite ends are bent to form individual latch shoes 31A and 31B respectively.
FIGS. 16 and 17 illustrates an elevational and top view of the latch spring 29 of the present invention. The latch spring 29 provides a force to the latch member 28 operating against the link pin 33 that pushes the latch shoes 31A and 31B away from the link pin 33 which in turn pulls the contact plate 41 into contact with the inner rocker arm 18 at contact surface 18A which causes the rocker arm assembly 14 to actuate the engine poppet valve 6 (the active mode) when the actuator 16 is non-energized. The contact arms 80A and 80B press against their respective latch shoes 31A and 31B respectively and react through the spring coils 84A, 84B to the link pin 33 where the spring coils 84A, 84B are attached to the link pin 33 by engagement of the extension arms 82A, 82B through engagement holes formed in the ends of the link pin 33 on either side of the latch member 28.
FIG. 18 is a cross-sectional view of the link pin 33 showing the pivoting section 96 where the link pin 33 contacts and pivots on the plunger 30. Also shown is the oil passageway 94 which extends from the pivoting section 96 allowing lubricant from the lash adjuster 5. The extension pins 92A and 92B extend to support and guide the latch member 28. Clip apertures 90A and 90B are formed in the extension pins 92A and 92B respectively and function to retain the latch spring 29 in position to react against the latch shoes 31.
FIG. 19 is an end view of the link pin 33 showing the semicircular shape which allows the saddle portion 50 (see FIG. 8) of the inner rocker arm 18 to pivot on top of the link pin 33.
Now referring to FIG. 20, a cross-sectional view of the inner rocker arm 18 rotatably supported at the saddle portion 50 on the link pin 33 which is rotatably supported on the plunger 30 is shown. A center oil passage 98 formed in the plunger 30 allows lubricant to flow onto the link pin 33 and onto the inner rocker arm 18 for reducing the level of friction when the link pin 33 rotates on the plunger 30 and the inner rocker arm rotates on the link pin 33 and when the inner rocker arm 18 rotates relative to the outer rocker arm 22.
While the invention has been illustrated and described in some detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are to be considered within the scope of the invention and only limited by the following claims. | A valve control system for an internal combustion engine. The system includes an outer rocker arm which is engageable with an engine poppet valve, and an inner rocker arm which is engageable with a cam lobe formed in an engine camshaft and a slidable latch member which mechanically links and unlinks the inner and outer rocker arms. The latch member is axially moveable relative to the inner and outer rocker arms between an active position wherein the inner rocker arm engages the outer rocker arm to transmit a valve opening force from the camshaft to the poppet valve, and an inactive position wherein the inner and outer rocker arms are out of engagement and free to rotate relative to one another. The system is adapted for use in a valve train wherein the engine poppet valve remains closed when the inner and outer rocker arms are unlinked when the latch member is in an inactive position and wherein the engine poppet valve opens and closes in response to the cam lobe when the inner and outer rocker arms are linked together when the latch member is in an active position. An actuator operates a bellcrank mechanism which contacts the latch mechanism to move the latch mechanism to an active and an inactive position. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to high-performance multilayer composite hollow fibers including at least one nonporous membrane layer and suitable for the separation of gases and for other purposes, as well as a method of making the same.
2. Description of the Prior Art
A large number of methods for the separation and purification of substances have been developed and improved from long ago.
The membrane separation technique is one of these methods. On a broad survey of the progress of its improvement, the general trend of technological advancement involves the development of excellent membrane materials, the development of techniques for forming thin membranes serving to enhance separating efficiency and the development of hollow fibers capable of enhancing equipment efficiency.
Among various separating membranes are nonporous membranes useful for the separation of gases and for other purposes. In such a nonporous membrane, the permeation rate for a gas is determined by its diffusion through the membrane, and the diffusion rate of the gas is greatly influenced by the thickness of the membrane. Accordingly, it is common practice to make the nonporous membrane as thin as possible. Moreover, since such a thin nonporous membrane has inadequate strength, attempts have been made to form a composite structure by combining the membrane with a porous layer. As one of such techniques for the formation of a thin membrane, a method is being extensively employed in which a thin membrane is formed on a porous substrate according to the coating or vapor deposition process. However, when a coating material is applied to a porous substrate, it penetrates into the pores of the substrate and fails to form a substantially thin membrane. More specifically, the membrane is sufficiently thin in the regions not corresponding to the pores of the porous substrate, but is undesirably thick in the regions corresponding to the pores. If an attempt is made to overcome this disadvantage by reducing the thickness of the membrane in the regions corresponding to the pores, pinholes will appear. For this reason, it is practically impossible to form a thin membrane of uniform thickness according to this method.
In order to overcome the above-described disadvantage, another method has been proposed in which the pores of a porous substrate are filled with a soluble material in advance, a thin membrane layer is formed on the surface of the substrate, and the soluble material is then leached out of the substrate. However, this method can hardly yield a thin membrane layer of uniform thickness. Moreover, this method is disadvantageous in that the thin membrane layer is liable to be damaged during the leaching process and in that the thin membrane layer tends to peel away from the finished composite membrane. Furthermore, it is difficult to apply this method to the manufacture of hollow fibers.
Still another method for forming a thin separating membrane is the formation of an asymmetric membrane from a polymer solution. For example, reverse osmosis membranes formed of aromatic polyamide and ultrafiltration membranes formed of polyacrylonitrile are being commercially produced by this method.
However, all of these membranes are formed according to such a technique that, in forming a membrane from a polymer solution, the superficial part of the membrane is solidified densely and the internal part thereof is made porous by selection of proper solidifying conditions or by use of the leaching process. Thus, these separating membranes consist of a single material.
Accordingly, the structure of the membranes formed by this method changes continuously from the superficial dense part toward the internal porous part and includes an intermediate structural part performing no important function. This is not so desirable from the viewpoint of filtering efficiency.
Moreover, the thin, nonporous membrane layer performing a separating function is exposed on one side of these composite membranes. This is disadvantageous in that any mechanical force exerted during manufacture or use tends to result in pinholes or cause damage to the nonporous membrane layer.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a novel membrane structure including a very thin, nonporous separating membrane having excellent durability.
It is another object of the present invention to provide hollow fibers including a nonporous separating membrane having excellent separation characteristics.
It is still another object of the present invention to provide a method of making hollow fibers including a very thin, nonporous separating membrane which method permits such hollow fibers to be stably produced on an industrial scale.
According to the present invention, there is provided a multilayer composite hollow fiber comprising at least one nonporous separating membrane layer (A) performing a separating function and two or more porous layers (B) performing a reinforcing function, the layer (A) and the layers (B) being alternately laminated so as to give a structure having inner and outer surfaces formed by the porous layers (B).
According to the present invention, there is also provided a method of making a multilayer composite hollow fiber as described above which comprises the steps of co-spinning a polymer (A') for forming the separating membrane layer and a polymer (B') for forming the porous layers through a spinning nozzle of multiple tubular construction so as to sandwich the polymer (A') between two layers of the polymer (B'), and stretching the resulting hollow fiber so as to make the layers (B) porous while leaving the layer (A) nonporous.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The hollow fibers of the present invention have a structure in which one or each thin separating membrane layer (A) is sandwiched between two highly permeable, porous layers (B).
Specifically, the hollow fibers are composed of at least three layers. The outermost and innermost layers consist of porous layers (B) serving as reinforcements, while the intermediate layer consists of a very thin membrane layer (A) performing a separating function. Basically, a separating membrane layer (A) of single-layer construction will suffice. However, the separating membrane layer (A) may optionally be composed of two or more sublayers according to the intended purpose. By using such a separating membrane layer (A) of multilayer construction, its possible impairment of performance due to pinholes and similar defects can be minimized. Although nothing can be better than the absence of pinholes and similar defects, there is an unavoidable tendency for such defects to increase as the separating membrane is made thinner so as to enhance the separating performance to the utmost. Consequently, such hollow fibers must be produced on the basis of a trade-off among membrane thickness, performance and defect level. From the standpoint of a manufacturer, it is a great advantage that little care is required to prevent the development of defects.
Generally, the layer performing a separating function is the most important of all layers constituting a separating membrane. If this layer is situated on the outermost side of the membrane, there is a risk of causing damage to its surface during handling or the like. In contrast, the hollow fibers of the present invention are desirably free from such a risk because the separating membrane layer (A) performing a separating function constitutes an intermediate layer of a structure consisting of three or more layers.
In the practice of the present invention, a variety of polymers may be used as the polymer (A') for forming the nonporous separating membrane layer (A). Examples of such polymers include silicones, polyurethanes, cellulosics, polyolefins, polysulfones, polyvinyl alcohol, polyesters, polyethers, polyamides and polyimides.
It may be practically impossible to form some of these polymers into a film. However, the present invention only requires that a separating membrane formed of the aforesaid polymer (A') is present in the finished hollow fibers. Accordingly, there may be used any polymer that can have the form of a viscous fluid at the time of spinning.
Thus, the polymer (A') need not be a straightchain polymer having solubility or fusibility.
More specifically, if it is difficult to melt a polymer in itself, it may be used in the form of a solution or in the state of a prepolymer. Alternatively, its fluidity may be controlled by the addition of a suitable plasticizer. The plasticizer can be any of various compounds that are commonly used as plasticizers. However, it is preferable to use a plasticizer selected from phthalic acid esters, fatty acid esters, glycerol, polyethylene glycol and the like.
As the polymer (B') for forming the porous layers (B), there may be used any material that can form hollow fibers. However, judging from the ease of manufacture and the paucity of soluble matter, it is preferable to use a crystalline material which can be formed to the hollow fiber by melt spinning and can be made porous by stretching it at low or ordinary temperatures to create microcrazes between crystals. Among the materials useful for this purpose are crystalline thermoplastic polymers. Specific examples thereof include polyolefins, as typified by polyethylene and polypropylene, polycarbonates, polyesters and the like.
Where the porous layers (B) are formed by stretching, it is to be understood that, under the stretching conditions for forming the porous layers (B) performing a reinforcing function, the separating membrane layer (A) performing a separating function must be amenably stretched so as to remain nonporous.
To this end, a noncrystalline polymer may be used as the polymer (A') for forming the separating membrane layer (A). Alternatively, where a crystalline polymer is used as the polymer (A'), it should have a lower melting point or a greater melt index than the polymer (B') for forming the porous layers (B) performing a reinforcing function. It is a matter of course that, as described above, a solvent or a plasticizer may be added to the polymer (A') so as to enhance its fluidity.
The hollow fibers of the present invention preferably have an internal diameter of 0.1 to 5 mm and a wall thickness of 10 to 1000 μm. From the viewpoint of separating efficiency, the thickness of the separating membrane should preferably be not greater than 5 μm and more preferably not greater than 2 μm.
The hollow fibers of the present invention have a multilayer composite structure in which one or each nonporous separating membrane layer performing a separating function is sandwiched between two porous layers performing a reinforcing function. Thus, no bond is needed between the layers and the materials of the layers may be chosen without consideration for their bonding properties. This is beyond imagination in the case of flat membranes and constitutes one of the distinctive features of hollow fibers.
Now, the present method of making a multilayer composite hollow fiber will be more specifically described hereinbelow in accordance with an embodiment in which the porous layers performing a reinforcing function is formed by melt spinning and subsequent stretching.
As described above, a crystalline thermoplastic polymer is used as the polymer (B') for forming the porous layers performing a reinforcing function, whereas a noncrystalline polymer or a polymer having a lower melting point or a greater melt index than the polymer (B') is used as the polymer (A') for forming the separating membrane layer performing a separating function. Using a spinning nozzle of the multiple tubular construction, a composite hollow fiber is spun in such a way that the polymer (B') forms the outermost and innermost layers and the polymer (A') is sandwiched therebetween.
The spinning nozzle may have three or five concentrially arranged orifices.
For this purpose, it is preferable to employ an extrusion temperature ranging from the melting point of the polymer (B') to a temperature about 80° C. higher than the melting point, and it is also preferable to employ a spinning draw ratio of not less than 30. If the extrusion temperature is higher than the melting point by more than about 80° C., it is difficult to achieve stable spinning. If the spinning draw ratio is less than 30, the melt-spun polymer (B') has a low degree of orientation and cannot be satisfactorily drawn in a subsequent stretching step. As a result, it is difficult to form micropores in the layers (B).
The hollow fiber so formed is preferably annealed at a temperature ranging from the glass transition point to the melting point of the polymer (B'). Thereafter, the hollow fiber is stretched with a stretch ratio of 5 to 150% at a temperature ranging from 0° C. to a temperature 5° C. lower than the melting point of the polymer (B') so as to create microcrazes in the layers (B) consisting of the polymer (B'). Then, the hollow fiber is stretched in one or more stages at a temperature higher than the aforesaid stretching temperature and lower than the melting point of the polymer (B'). This serves to expand the pores formed by the microcrazes and stabilize the shape of the pores. Furthermore, in order to improve its thermal stability, the hollow fiber may be heat-treated under constant-length or relaxed conditions at a temperature ranging from the melting point of the polymer (B') to a temperature 5° C. lower than its melting point.
Where the polymer (A') forming the layer (A) is a noncrystalline polymer or a polymer containing a solvent or a plasticizer, the above-described stretching process does not make the layer (A) porous, but allows it to be amenably stretched with a gradual reduction in thickness. If the polymer (A') forming the layer (A) has a lower melting point than the polymer (B'), the extrusion temperature should be within the aforesaid extrusion temperature range but above a temperature 60° C. higher than the melting point of the polymer (A'), or the first-stage stretching temperature should be within the aforesaid stretching temperature range but above a temperature 70° C. lower than the melting point of the polymer (A'). If the polymer (A') forming the layer (A) is of the same type as the polymer (B') but has a melt index different from that of the polymer (B'), it is preferable to reduce its melt viscosity and thereby decrease the stress applied to the polymer melt for the purpose of suppressing the orientation and crystallization of the polymer (A'). More specifically, the layers (B) alone can be made porous by employing an extrusion temperature above a temperature 30° C. higher than the melting point of the polymer (A').
In the prior art, it has been difficult to form a thin membrane having a uniform thickness of not greater than 5 μm on a porous substrate. However, in the practice of the present invention and especially in its embodiment in which the layers (B) are made porous by stretching, the layers (B) become porous without any reduction in thickness, and the layer (A) alone is stretched at the intended stretch ratio and thereby reduced in thickness. Thus, the present invention make it possible to form a thin membrane having a smaller and more uniform thickness than has been attainable in the prior art.
The present invention is further illustrated by the following examples.
EXAMPLE 1
A hollow fiber was melt-spun from a combination of two different materials by using a spinning nozzle having three concentrically arranged annular orifices. Specifically, polyethylene having a density of 0.968 g/cm 3 and a melt index of 5.5 was melt-extruded through the innermost and outermost orifices of the nozzle, while polyethylene having a density of 0.920 g/cm 3 and a melt index of 5.0 was melt-extruded through the intermediate orifice of the nozzle. This spinning was carried out at an extrusion temperature of 160° C. and an extrusion line speed of 5 cm/min., and the hollow fiber so formed was taken up at a take-up speed of 800 m/min.
The unstretched hollow fiber thus obtained had an internal diameter of 200 μm and consisted of three concentrically arranged layers having thickness of 10, 2 and 10 μm, respectively, from inside to outside.
This unstretched hollow fiber was passed over a roller heated to 115° C. under constant-length conditions so as to bring the hollow fiber into contact with the roller for 100 seconds and thereby effect its annealing. Thereafter, the annealed hollow fiber was cold-stretched at a stretch ratio of 80% by rollers kept at 28° C., hot stretched by rollers in a box heated at 105° C. until a total stretch ratio of 400% was achieved, and then heat-set in a box heated at 115° C. while being relaxed by 28% of the total elongation to obtain a composite hollow fiber.
The hollow fiber thus obtained had an internal diameter of 190 μm and consisted of three concentrically arranged layers having thicknesses of 8, 0.6 and 8 μm, respectively, from inside to outside. Electron microscopic observation revealed that slit-like pores having a width of 0.3 to 0.5 μm and a length of 0.8 to 1.1 μm had been formed in the innermost and outermost layers. On the other hand, measurement of gas permeation rate revealed that the intermediate layer was a homogeneous membrane having neither pores nor pinholes. This composite hollow fiber had an oxygen permeation rate of 4.5×10 -6 cm 3 /cm 2 .sec.cmHg and a nitrogen permeation rate of 1.5×10 -6 cm 3 /cm 2 sec.cmHg, indicating that it was selectively permeable to oxygen and had an excellent permeation rate.
EXAMPLE 2
A hollow fiber was melt-spun from a combination of two different materials by using a spinning nozzle having three concentrically arranged annular orifices. Specifically, polypropylene having a density of 0.913 g/cm 3 and a melt index of 15 was melt-extruded through the innermost and outermost orifices of the nozzle, while poly-4-methylpentene-1 having a density of 0.835 g/cm 3 and a melt index of 26 was melt-extruded through the intermediate orifice of the nozzle. This spinning was carried out at an extrusion temperature of 250° C. and an extrusion line speed of 5 cm/min., and the hollow fiber so formed was taken up at a take-up speed of 400 m/min.
The unstretched hollow fiber thus obtained had an internal diameter of 280 μm and consisted of three concentrically arranged layers having thicknesses of 14, 1.5 and 17 μm, respectively, from inside to outside.
This unstretched hollow fiber was passed over a roller heated to 140° C. under constant-length conditions so as to bring the hollow fiber into contact with the roller for 100 seconds and thereby effect its annealing. Thereafter, the annealed hollow fiber was cold-stretched at a stretch ratio of 20% by rollers kept at 60° C., hotstretched by rollers in a box heated at 135° C. until a total stretch ratio of 200% was achieved, and then heat-set in a box heated at 140° C. while being relaxed by 28% of the total elongation to obtain a composite hollow fiber.
The hollow fiber thus obtained had an internal diameter of 265 μm and consisted of three concentrically arranged layers having thicknesses of 12, 0.7 and 14 μm, respectively, from inside to outside. Electron microscopic observation revealed that slit-like pores having a width of 0.07 to 0.09 μm and a length of 0.2 to 0.5 μm had been formed in the innermost and outermost layers. On the other hand, measurement of gas permeation rate revealed that the intermediate layer consisting of poly-4-methylpentene-1 was a homogeneous membrane having neither pores nor pinholes. This composite hollow fiber had an oxygen permeation rate of 4.7×10 -6 cm 3 /cm 2 .sec.cmHg and a nitrogen permeation rate of 1.5 ×10 -6 cm 3 /cm 2 .sec.cmHg, indicating that it was selectively permeable to oxygen and had an excellent permeation rate.
EXAMPLE 3
A hollow fiber was melt-spun from a combination of two different materials by using a spinning nozzle having three concentrically arranged annular orifices. Specifically, the same polypropylene as used in Example 2 was melt-extruded through the innermost and outermost orifices of the nozzle, while ethyl cellulose having a degree of ethoxylation of 49% was melt-extruded through the intermediate orifice of the nozzle. This spinning was carried out at an extrusion temperature of 205° C. and an extrusion line speed of 4 cm/min., and the hollow fiber so formed was taken up at a take-up speed of 300 m/min.
The unstretched hollow fiber thus obtained had an internal diameter of 290 μm and consisted of three concentrically arranged layers having thicknesses of 16, 1.9 and 18 μm, respectively, from inside to outside.
This unstretched hollow fiber was passed over a roller heated to 130° C. under constant-length conditions so as to bring the hollow fiber into contact with the roller for 180 seconds and thereby effect its annealing. Thereafter, the annealed hollow fiber was cold-stretched at a stretch ratio of 17% by rollers kept at 60° C., hot-stretched by rollers in a box heated at 130° C. until a total stretch ratio of 180% was achieved, and then heat-set in a box heated at 130° C. while being relaxed by 25% of the total elongation to obtain a composite hollow fiber.
The hollow fiber thus obtained had an internal diameter of 273 μm and consisted of three concentrically arranged layers having thicknesses of 14, 0.9 and 16 μm, respectively, from inside to outside. Electron microscopic observation revealed that slit-like pores having a width of 0.07 to 0.09 μm and a length of 0.1 to 0.4 μm had been formed in the innermost and outermost layers. On the other hand, measurement of gas permeation rate revealed that the intermediate layer consisting of ethyl cellulose was a homogeneous membrane having neither pores nor pinholes. This composite hollow fiber had an oxygen permeation rate of 2.3×10 -5 cm 3 /cm 2 sec.cmHg and a nitrogen permeation rate of 0.7×10 -5 cm 3 /cm 2 .sec.cmHg, indicating that it was selectively permeable to oxygen and had a very high permeation rate.
EXAMPLE 4
A hollow fiber was melt-spun from a combination of two different materials by using a spinning nozzle having three concentrically arranged annular orifices. Specifically, polyethylene having a density of 0.965 g/cm 3 and a melt index of 5.2 was melt-extruded through the innermost and outermost orifices of the nozzle, while an ultraviolet-curable silicone resin (commercially available from Toshiba Silicone Co., Ltd., under the trade name of TUV6020) was melt-extruded through the intermediate orifice of the nozzle. This spinning was carried out at an extrusion temperature of 160° C. and an extrusion line speed of 10 cm/min., and the hollow fiber so formed was taken up at a takeup speed of 350 m/min.
The unstretched hollow fiber thus obtained had an internal diameter of 290 μm and consisted of three concentrically arranged layers having thicknesses of 27, 2.5 and 32 μm, respectively, from inside to outside.
This unstretched hollow fiber was passed over a roller heated to 110° C. under constant-length conditions so as to bring the hollow fiber into contact with the roller for 100 seconds and thereby effect its annealing. Thereafter, while being irradiated with an 80 W/cm high pressure mercury vapor lamp from a distance of about 10 cm, the annealed hollow fiber was cold-stretched at a stretch ratio of 50% by rollers kept at 30° C., hot-stretched by rollers in a box heated at 100° C. until a total stretch ratio of 300% was achieved, and then heat-set in a box heated at 115° C. while being relaxed by 10% of the total elongation to obtain a composite hollow fiber.
The hollow fiber thus obtained had an internal diameter of 270 μm and consisted of three concentrically arranged layers having thicknesses of 22, 0.8 and 25 μm, respectively, from inside to outside. Electron microscopic observation revealed that the innermost and outermost layers had been made porous and that slit-like pores having a width of 0.1 to 0.3 μm and a length of 0.5 to 0.9 μm had been formed therein. On the other hand, measurement of gas permeation rate revealed that the intermediate layer consisting of silicone rubber was a homogeneous membrane having neither pores nor pinholes.
This composite hollow fiber had an oxygen permeation rate of 6.2×10 -4 cm 3 /cm 2 .sec.cmHg and a nitrogen permeation rate of 3.1×10 -4 cm 3 /cm 2 sec.cmHg, indicating its excellent selective permeability to oxygen.
EXAMPLE 5
A hollow fiber was melt-spun from a combination of two different materials by using a spinning nozzle having three concentrically arranged annular orifices. Specifically, the same polyethylene as used in Example 1 was melt-extruded through the innermost and outermost orifices of the nozzle, while a mixture of acetylcellulose having a degree of acetylation of 40% and polyethylene glycol used as a plasticizer (in an amount of 50% by weight based on the acetylcellulose) was melt-extruded through the intermediate orifice of the nozzle. This spinning was carried out at an extrusion temperature of 170° C. and an extrusion line speed of 7.5 cm/min., and the hollow fiber so formed was taken up at a take-up speed of 300 m/min.
The unstretched hollow fiber thus obtained had an internal diameter of 285 μm and consisted of three concentrically arranged layers having thicknesses of 25, 0.7 and 25 μm, respectively, from inside to outside.
This unstretched hollow fiber was passed over a roller heated to 110° C. under constant-length conditions so as to bring the hollow fiber into contact with the roller for 180 seconds and thereby effect its annealing. Thereafter, the annealed hollow fiber was cold-stretched at a stretch ratio of 60% by rollers kept at 30° C., hot-stretched by rollers in a box heated at 110° C. until a total stretch ratio of 300% was achieved, and then heat-set in a box heated at 110° C. while being relaxed by 25% of the total elongation to obtain a composite hollow fiber.
The hollow fiber thus obtained had an internal diameter of 260 μm and consisted of three concentrically arranged layers having thicknesses of 18, 0.2 and 19 μm, respectively, from inside to outside. Electron microscopic observation revealed that slit-like pores having a width of 0.1 to 0.2 μm and a length of 0.4 to 0.8 μm had been formed in the innermost and outermost layers. On the other hand, measurement of gas permeation rate revealed that the intermediate layer consisting of acetylcellulose was a homogeneous membrane having neither pores nor pinholes. This composite hollow fiber had an oxygen permeation rate of 1.2×10 -5 cm 3 /cm 2 sec.cmHg and a nitrogen permeation rate of 0.4×10 -5 cm 3 /cm 2 .sec.cmHg, indicating that it was selectively permeable to oxygen and had a very high permeation rate.
EXAMPLE 6
A hollow fiber was melt-spun from a combination of two different materials by using a spinning nozzle having three concentrically arranged annular orifices. Specifically, the same polypropylene as used in Example 2 was melt-extruded through the innermost and outermost orifices of the nozzle, while a mixture of polyvinyl alcohol having a degree of saponification of 99 mole % and a degree of polymerization of 1700 and glycerol used as a plasticizer (in an amount of 50% by weight based on the polyvinyl alcohol) was melt-extruded through the intermediate orifice of the nozzle. This spinning was carried out at an extrusion temperature of 200° C. and an extrusion line speed of 7 cm/min., and the hollow fiber so formed was taken up at a take-up speed of 300 m/min.
The unstretched hollow fiber thus obtained had an internal diameter of 320 μm and consisted of three concentrically arranged layers having thicknesses of 25, 1.2 and 27 μm, respectively, from inside to outside.
This unstretched hollow fiber was passed over a roller heated to 130° C. under constant-length conditions so as to bring the hollow fiber into contact with the roller for 180 seconds and thereby effect its annealing. Thereafter, the annealed hollow fiber was cold-stretched at a stretch ratio of 17% by rollers kept at 60° C., hot-stretched by rollers in a box heated at 130° C. until a total stretch ratio of 150% was achieved, and then heat-set in a box heated at 130° C. while being relaxed by 25% of the total elongation to obtain a composite hollow fiber.
The hollow fiber thus obtained had an internal diameter of 300 μm and consisted of three concentrically arranged layers having thicknesses of 21, 0.5 and 23 μm, respectively, from inside to outside. Electron microscopic observation revealed that slit-like pores having a width of 0.07 to 0.09 μm and a length of 0.1 to 0.3 μm had been formed in the innermost and outermost layers. On the other hand, measurement of gas permeation rate revealed that the intermediate layer consisting of polyvinyl alcohol was a homogeneous membrane having neither pores nor pinholes.
Using composite hollow fibers made in the above-described manner, an aqueous ethanol solution having an ethanol concentration of 90% by weight was separated according to the pervaporation technique. Thus, it was found that the flux was as high as 29 kg/m 2 .hr and the separation factor (αH 2 O/C 2 H 5 OH) was 80, indicating that these hollow fibers were selectively permeable to water. These hollow fibers made it possible to concentrate the aqueous ethanol solution to a concentration higher than 99% by weight. | Disclosed are a multilayer composite hollow fiber comprising at least one nonporous separating membrane layer (A) performing a separating function and two or more porous layers (B) performing a reinforcing function, the layer (A) and the layers (B) being alternately laminated so as to give a structure having internal and external surfaces formed by the porous layers (B), as well as a method of making such a hollow fiber.
In this multilayer composite hollow fiber, the separating membrane can be formed as an ultrathin, homogeneous membrane. Moreover, the separating membrane is not liable to get damaged owing to the unique structure of the hollow fiber. Furthermore, such hollow fibers can be readily and stably produced on an industrial scale. | 3 |
CROSS-REFERENCE TO RELATED APPLCIATIONS
[0001] This application claims the benefit of Swiss Patent Application No. 00928/09, filed Jun. 15, 2009, which is incorporated herein by reference as if fully set forth.
BACKGROUND
[0002] The invention is directed to a placement device and a method for placing decorative elements on a textile or non-textile sheet material.
[0003] Articles of clothing, as well as other textile and non-textile sheet materials can be embellished by applying decorative elements, such as sequins, rhinestones, rivets, and the like. Such applications are realized conventionally by industrial machines constructed especially for each task. Rhinestones are normally covered on the back side with a hot-melt layer. For the industrial production of motifs or arrangements of rhinestones on articles of clothing, the individual rhinestones are typically separated from bulk supplies, arranged, and placed onto the article of clothing. The fixing or connecting process to the article of clothing is performed immediately after the setting process, wherein the hot-melt adhesive is activated, e.g., by supplying energy by an ultrasonic sonotrode. It is also known to apply industrially prefabricated motifs in mirror-inverted representation on transfer films. Here, the rhinestones are placed on this transfer film with the visible side directed toward the self-adhesive transfer film and then covered with an additional protective film. Such arrangements of rhinestones produced as unfinished products can then be purchased and bonded on surfaces in the desired way or connected rigidly to these surfaces by means of conventional flat irons or presses. For guaranteeing high quality, the most uniform possible supply of a certain quantity of energy to each of the rhinestones is advantageous.
[0004] Alternatively, rhinestones could also be applied at home, e.g., individually by tweezers onto a transfer film. Or the rhinestones are held and placed directly onto the article of clothing. Then, through a piston-like applicator with an electrical heating device or an ultrasonic sonotrode, the required energy is fed for heating the adhesive for connecting the rhinestone to the article of clothing. Such applicators can be adapted, e.g., by adapters to different sizes and shapes of the rhinestones.
[0005] Conventionally, the efficient application of individually shaped rhinestone arrangements on articles of clothing is possible only by expensive machines designed for commercial use. These machines are constructed only for the application of rhinestones and are not suitable for other decorative elements.
SUMMARY
[0006] Therefore, the objective of the present invention is to create a device and a method that allow, also in the home, a simple and efficient production of individual rhinestone applications. An additional task of the invention lies in constructing the device and the method so that, as an alternative or addition to rhinestones, other decorative elements, such as, e.g., rivets, sequins, stones, films, stamps, etc., can also be applied onto a sheet material.
[0007] These tasks are achieved by a placement device that can be connected to a sewing machine and by a placement method for textile and non-textile sheet materials according to the invention.
[0008] The invention uses the knowledge that the placement of decorative elements at certain positions of an sheet material has similarities with the construction of sewing stitches by a sewing machine during sewing or embroidery, and that functions of a sewing machine—be it now functions of the electronic sewing machine control or mechanical movement sequences—can be used for the arrangement of decorative elements at certain positions of an sheet material. The placement device according to the invention is connected to a household sewing machine and uses functions of this sewing machine for applying or setting decorative elements at positions that are or can be specified in advance on a textile or non-textile sheet material. For an advantageous construction of the invention, instead of a conventional presser foot, the placement device can be attached to the presser foot bar of the sewing machine. The placement device comprises a placement head that can be controlled by the control of the sewing machine for the sequential application of decorative elements at positions that can be or are specified in advance on the sheet material. For this purpose, the sheet material can be moved relative to the placement device selectively, e.g., by hand or by an embroidery hoop or by a different positioning or transport device, such as, e.g., the feed dog of the sewing machine. Alternatively, the placement device or the sewing machine with the placement device could also be moved equivalently relative to the sheet material.
[0009] The individual set positions can be stored, e.g., analogous to the embroidery positions when embroidering with an embroidery program and can be called up by the sewing machine control.
[0010] According to the construction of the invention, the term “control” can comprise only the sewing machine control itself or also one or more additional control devices interacting with the sewing machine control, for example, control electronics of the placement device or an embroidery hoop or a computer with a higher rank than the sewing machine. The decorative elements are ready-to-use and—in contrast to bulk goods—are stored in a defined way in a storage medium or magazine. Such a magazine could have a different construction. Through the use of a corresponding feeder device, the magazine or parts of this can be moved in a controlled way by the control, such that decorative elements stored in the magazine can be relocated by the placement head from the magazine to the desired positions on the sheet material. Alternatively, the feeder device could also move the decorative elements directly, in order to bring these into a suitable transfer position. The application of the decorative elements can be performed selectively by hand or individually (e.g., triggered by a foot switch) or controlled by a program or automatically (analogous to an embroidery program).
[0011] The placement head can be constructed and act differently consistent with the magazines being used and each feeding device. It could comprise, for example, a shuttle or a collet chuck with which the decorative element is moved in a suitable way to the corresponding support position and then released again at the set position on the sheet material. The placement head can also comprise an element for pressing decorative elements out from a hold of the magazine and/or for pressing decorative elements onto the sheet material, wherein the contact force advantageously can be set or adjusted or controlled. In particular, the placement head could be arranged and constructed so that it can be activated by movements or by the application of force by the needle bar. Alternatively or additionally, other movements of the sewing machine, such as, e.g., those of the sewing foot presser bar or the feed dog (in or perpendicular to the sewing direction) or the application of forces from additional drives (e.g., step motors, magnets, pneumatic suction devices) could also be used to move the placement head so that it takes decorative elements from the magazine and arranges them in the desired way on the sheet material.
[0012] For an advantageous construction of the invention, the magazine is constructed like a kind of cartridge or a parts dispenser. This is lowered at each of the set positions by the movement of the needle bar in the direction of the sheet material. Shortly before reaching the lowermost position, e.g., an activation lever constructed on the magazine contacts a step of the placement device or on the sheet material. For the further lowering of the magazine, a slide or a flap is opened on the magazine, so that an individual decorative element falls from the magazine directly on the sheet material at the provided position. If the placement device is constructed accordingly, the decorative element can also be pressed onto a transfer film. Therefore, a better fixing on the sheet material is possible. Due to the small distance to the sheet material and optionally, e.g., a funnel-like guide constructed on the placement device, the decorative element comes to lie exactly on the desired position or set position on the sheet material. Alternatively, the decorative element could also be transferred in an analogous way to a moving arm or lever or placement device and fed indirectly from this to the provided position.
[0013] Advantageously, the magazines have supporting positions adapted to the geometry of the corresponding decorative elements. These supporting positions can be arranged or lined up relative to each other, e.g., at specified constant or standardized distances. An example here is a transport tape or carrier tape with tubs in an equidistant arrangement as supporting positions. Feeding devices for such magazines could be constructed very easily, because the carrier tape must be advanced by only a given distance between two adjacent supporting positions. For this purpose, for example, the sewing movement (up-and-down movement) or the zigzag movement of the needle bar can be used, wherein, e.g., one or more pins connected to the needle bar engage in a regular perforation arrangement along the carrier tape. For alternative embodiments of the placement device, differently constructed magazines, such as, e.g., revolvers or rotary plates, and/or other drives, such as, e.g., step motors or pneumatic parts operating with an overpressure and/or negative pressure can be used for moving magazines and/or parts of magazines and/or decorative elements supported in magazines. There is also the ability for the magazines to have a refillable construction, such that these can be loaded individually with a desired combination of identical or different decorative elements. For placement, the decorative elements are placed in the specified sequence of support positions at the provided set positions on the sheet material.
[0014] As an alternative to supporting positions lined up in one dimension, magazines could also comprise supporting positions arranged in a defined way like an array in several rows or in a different way. If necessary, additional parameters could be set for individual supporting positions of the magazines or for groups of supporting positions, wherein these parameters can be taken into account by the control for setting the decorative elements. Such parameters can comprise, for example, information on the type, size, color, desired connection technique, etc., of the decorative elements supported at these support positions and/or information on the support positions themselves, e.g., information on their shape, size, arrangement, orientation, and the like. Such parameters can be reported to the control, e.g., by an input terminal and stored in a storage medium. Alternatively, sensors could also be provided for detecting individual, multiple, or all of the parameters to be detected. In particular, for this purpose, an image sensor or a camera could be used in connection with an image-processing device. As an alternative to the direct detection of such parameters, these could also be detected in advance during production or during the filling of the magazines and stored in a suitable storage medium on each magazine. Such storage media are, e.g., stitch codes or RFID tags. They could be detected by a corresponding reading device of the placement device and processed by the control.
[0015] The consideration of such information detected and stored in advance makes the placement process significantly more flexible: with reference to stored parameter values, e.g., a targeted access to supporting positions of difference decorative elements is possible. In this case, it is not necessary to access adjacent supporting positions in a specified sequence.
[0016] The orientation of a decorative element or its positional angle relative to the sheet material can be, according to the construction of the invention, e.g., random or defined by a forced or specified position of the decorative element at or in the supporting positions of the magazine. Thus, the supporting positions could comprise, e.g., springs or other elastically flexible parts, such as coverings that are made from silicon rubber and that hold the decorative elements in a defined position. As an alternative or addition, the placement head could comprise a rotating device that could be used for orienting the decorative element. In connection with a camera, the control can automatically recognize the position and situation of decorative elements at the supporting positions of the magazines and can place the decorative elements in the specified orientation on the sheet material. The invention comprises magazines and feeding devices in different constructions. Advantageously, for moving the feeding device and/or the placement head, drives of the sewing machine are used (e.g., drive for the needle bar movement, the zigzag movement of the needle bar, feed dog drive, lifting movement of the sewing presser foot bar). Alternatively or additionally, motors of an embroidery module (x-y table) connected to the sewing machine or other external actuators that can be controlled by the sewing machine, such as, e.g., magnets or step motors could also be used for this purpose. Suitable magazines are, e.g., carrier tapes, belts, cassettes, cartridges, parts dispensers, capsules connected flexibly or rigidly to each other, rotary plates, and the like.
[0017] With the placement device according to the invention, decorative elements can be placed selectively on textile or non-textile sheet materials. In particular, decorative elements could also be applied to transfer films and later connected to the desired surfaces.
[0018] In addition to setting or arranging the decorative elements, the placement device can also comprise a joining or connecting device for the temporary or permanent connection of the decorative elements to the sheet materials. This connecting device can be constructed for performing one or more different joining techniques. Examples here are hot melt adhesive, gluing, welding, sewing, rivets. The individual decorative elements are advantageously connected to the sheet material during or immediately after the setting, so that they maintain the desired positioning. For this purpose, the connecting device could be formed completely or partially on the placement head.
[0019] For activating a hot-melt adhesive on the decorative element, the required thermal energy can be supplied locally to this element, e.g., in a non-contact method by a laser or through contact with an applied ultrasonic sonotrode or an electrical heating device.
[0020] For bonding decorative elements by other adhesives, the placement device can advantageously comprise a glue dispenser on the placement head. Before placing and pressing a decorative element on the sheet material, a small dose of adhesive is deposited either on the bottom side of the decorative element or on the provided placement site of the sheet material. Alternatively, the bottom sides of the decorative elements could also be equipped with micro-encapsulated adhesive. During placement, these decorative elements are pressed with sufficient force onto the sheet material. In this way, the micro-capsules burst. The released adhesive connects the decorative elements to the sheet material.
[0021] Certain decorative elements, such as, e.g., rivets or deformable foil or stamp parts, can be attached on the sheet material by shaping techniques, such as, riveting or crimping. Perforated decorative elements, such as, e.g., sequins or buttons, could also be sewn tightly on the sheet material. This obviously also applies for textile or other parts that can be pierced by a sewing needle or for fitted parts or parts to be sewn on in some other way. Because the sewing machine is already constructed for this connection technique, it is not necessary to also construct a corresponding connecting device on the placement device. If the placement device is to be used in connection with a sewing process for attaching the decorative elements, then they must be constructed and attached to the sewing machine, so that the sewing process is not hindered. Decorative elements can be sewn tight, e.g., immediately after being set. Alternatively, the decorative elements could also be placed in a first processing step temporarily, e.g., by means of a replaceable double-sided adhesive non-woven material on the sheet material and then sewn tight in a second processing step. Such non-woven materials can also contain adhesives for a permanent connection that can be activated, e.g., by pressure.
[0022] The placement device or parts of this can be connected as described to the sewing machine in the region of the sewing machine head above the sheet material to be processed or alternatively in the region of the bottom arm of the sewing machine underneath the sheet material to be processed. Combinations with interacting, active and/or passive parts on both sides of the sheet material to be processed are also possible. Thus, for example, the placement head could be attached to the sewing foot pressure bar above the sheet material and activated by the movement of the needle bar. The stitch plate of the sewing machine can be replaced, e.g., by a passive work plate that comprises contact zones corresponding to the placement head for pressing the decorative elements. In addition, in the region of the bottom arm or the work plate, templates needed, e.g., for crimping, stamping, or riveting for the shaping or some other processing of the decorative elements could be constructed. Instead of or in addition to such passive elements or connection means, active elements for connecting the decorative elements to the sheet material could also be provided. Examples here are heating devices, ultrasonic sonotrodes, or UV light sources for activating or hardening the adhesive. For alternative embodiments of the placement device, decorative elements could also be placed on the sheet material from the bottom side or on both sides.
BRIEF DESCRIPTON OF THE DRAWINGS
[0023] Two example embodiments of the invention are described in detail with reference to the drawing figures. Shown here are
[0024] FIG. 1 is a schematic representation of a placement device attached to the sewing foot presser bar in a first embodiment.
[0025] FIG. 2 is a schematic representation of a placement device attached to the sewing foot presser bar in a second embodiment for the removal of a rhinestone from a cartridge-like magazine.
[0026] FIG. 3 is a view of the placement device from FIG. 2 , wherein the rhinestone is relocated by a lever mechanism into a position suitable for placement on a transfer film.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] In a schematic representation, FIG. 1 shows a first embodiment of a placement device 3 that is used for decorative elements 5 and that is attached analogously to a presser foot to a material pressure foot or presser foot 1 of a sewing machine. In the illustrated example, these decorative elements 5 are rhinestones 5 a that are held detachably at regular or identical intervals A on a tape-shaped, rolled-up carrier tape 7 a. The carrier tape 7 a is a special construction of a magazine 7 that is constructed for the ordered storage of decorative elements 5 and for feeding these decorative elements 5 to a part of the placement device 3 designated, in general, as placement head 9 . The placement device 3 comprises a base part 11 with a sewing presser foot shaft 13 for holding the normally conical lower end of the sewing pressure foot bar 1 . The base part 11 is connected rigidly to the sewing presser foot bar 1 analogous to a sewing presser foot by a retaining clip 15 . On the base part 11 , a replaceable supply roll 17 and a take-up roll 19 are each supported so that they can rotate. The carrier tape 7 a with the rhinestones 5 a is rolled up on the supply roll 17 . The front end of the carrier tape 7 a is connected to the take-up roll 19 so that the carrier tape 7 a can be unwound from the supply roll 17 onto the take-up roll 19 . Between the supply roll 17 and the take-up roll 19 , the carrier tape 7 a is guided by a convexly curved guide web 21 constructed on the bottom side of the base part 11 under the needle bar 23 of the sewing machine. Advantageously, the carrier tape 7 a is held slightly in tension between the supply roll 17 and the take-up roll 19 , so that it contacts the guide web 21 in a defined way. In the region of the lowest-lying position of the guide web 21 , a continuous borehole 25 is defined coaxial to the needle bar axis, wherein a pin or press plunger 27 is supported so that it can be moved in this borehole in the axial direction. The press plunger 27 is loaded by a restoring spring 28 and held on the guide web 21 or, in general, on the base part 11 , such that its lower-lying contact face 29 does not project beyond the borehole 25 without the action of additional forces. An advantageously impact-damping contact plate 31 is formed on the upper end of the press plunger 27 .
[0028] For performing a lowering movement of the needle bar 23 in the direction of arrow B 1 , as it is otherwise constructed for sewing or embroidering, a feeding device 35 (shown only symbolically by a rectangle for the sake of better clarity) transports the carrier tape 7 a forward by an advance length that corresponds to the distance A between adjacent bearing positions of the carrier tape 7 a. The downward movement of the needle bar 23 is used for driving the feeding device 35 . For this purpose, e.g., a catch (not shown) can extend on the needle bar 23 , wherein this catch comes in contact with a corresponding activation lever (not shown) on the base part 11 for the downward movement of the needle bar 23 . The activation lever is moved at least on one section of the downward movement of the needle bar 23 by the catch and thus drives the feeding device 35 . The feeding device 35 can comprise, e.g., a latch mechanism (not shown) that moves the carrier tape 7 a forward exactly by the desired advance length in the provided feeding direction. Alternatively or additionally, the movement of the needle bar 23 could also be used to rotate the take-up roll 19 and/or the supply roll 17 in a corresponding way or to tension a spring drive (not shown) that keeps the carrier tape 7 a slightly tensioned between the supply roll 17 and the take-up roll 19 . In this position, the decorative element 5 located under the press plunger 27 has a small distance H 1 to the sheet material 39 of, for example, 2 to 4 mm. Advantageously, this distance H 1 is somewhat larger than twice the maximum height H 2 of that of the decorative element 5 to be placed, with the height of this element typically lying, in the case of rhinestones 5 a, on the order of magnitude of approximately one to two millimeters. In this way it is achieved that the sheet material 3 can still be moved freely in a horizontal placement plane even for decorative elements 5 that have been already placed. Alternatively, the feeding device 35 could also be driven by upward movements or by zigzag movements of the needle bar constructed perpendicular to these upward movements. By advancing the carrier tape 7 a, the next support position with the next decorative element 5 to be placed comes to lie directly under the press plunger 27 . In agreement with the advancement of the carrier tape 7 a, the take-up roll 19 and the supply roll 17 rotate in rotational directions specified by the arrows B 2 and B 3 .
[0029] After the decorative element 5 to be placed has been brought into the correct transfer position under the press plunger 27 through the advancing of the carrier tape 7 a, for further lowering of the needle bar 23 , its lower end or the needle holder 33 arranged there contacts the contact plate 31 shortly before reaching the reversing point. For the further downwards movement, the needle bar 23 presses the press plunger 27 downward against the force of the restoring spring 28 . The contact face 29 presses from the back side against the carrier tape 7 a, and, indeed, exactly at the support position with the decorative element 5 to be placed. In this way, the decorative element 5 is released from the carrier tape 7 a and falls onto the sheet material 39 that is located at a small distance underneath and that is tensioned in an embroidery hoop 37 . In the shown example, the sheet material 39 is a self-adhesive transfer film. The flexible carrier tape 7 a comprises an adhesive layer or advantageously isolated adhesive spots at the individual bearing positions on the side facing the sheet material 39 . The back sides of the rhinestones 5 a that are opposite the visible sides and that coated with activatable adhesive are attached in a detachable way on the carrier tape 7 a at their adhesive positions. As an alternative to attaching the rhinestones 5 a by adhesive, the supporting positions of the carrier tape 7 a can also comprise, e.g., receptacles made from silicone or a different elastically spring-like material that surround the decorative elements 5 in a non-positive fit and hold them in a defined position on the carrier tape 7 a. For the back-side pressure of the press plunger 27 , the decorative elements 5 are released from the hold and placed on the sheet material 39 .
[0030] As an alternative to letting the decorative elements 5 fall from a low height, the carrier tape 7 a could also be pressed downward by the stroke of the press plunger 27 (due to the movement of the needle bar 23 up to its lower reversing point) and/or optionally by the vertical lifting movement of the sewing foot presser bar 1 . The lowering movement of the sewing foot presser bar 1 with the base part 11 attached to it is shown in FIG. 1 by the arrow B 4 . The decorative elements 5 are pressed by the press plunger 27 onto the sheet material 39 . If the lowering movement of the spring-mounted sewing foot presser bar 1 is used for pressing the decorative element 5 onto the sheet material 39 , then the decorative elements 5 can be pressed onto the sheet material 39 in a simple way with a contact pressure force that is or can be specified. The sheet material 39 is here supported on a work plate 41 . As the work plate 41 , for simple constructions of the invention, the stitch plate of the sewing machine can be used. In this case, the axes of the needle bar 23 and the press plunger 27 are advantageously arranged slightly offset relative to each other, so that a suitable contact face of the stitch plate without openings or other interfering elements lies directly underneath the press plunger 27 . For alternative constructions, the work plate 41 could also comprise passive or active parts that have a certain function for setting and optionally for connecting the decorative elements 5 to the sheet material 39 . Such parts are passive anvils that are, e.g., flat or adapted to the shape of the decorative elements 5 and to the corresponding connection technique or active stop elements that are formed, e.g., for heating the connection point between the pressed decorative element 5 and the sheet material 39 . Heating can be performed, e.g., by electrical heating elements, laser light, or ultrasound.
[0031] When placing on a transfer film, normally no active parts are required on the side of the work plate 41 . For a corresponding stroke of the press plunger 27 and the sewing foot presser bar 1 , the decorative elements 5 could also be pressed onto the adhesive layer of the transfer film with a specified force. If the decorative elements 5 are likewise attached with adhesive on the carrier tape 7 a, then the adhesion there should be lower than for the adhesive of the transfer film. For contact with the transfer film, the decorative elements thus remain bonded to the transfer film, if the needle bar 23 and thus also the press plunger 27 moves upward again.
[0032] The sewing machine control or a computer with a higher rank than this control controls the embroidery module connected to the sewing machine with the movable embroidery hoop 37 and the sheet material 39 tensioned in this hoop and the placement device 3 analogous to an embroidery program in the way that, instead of sewing stitches, decorative elements 5 are placed on the sheet material 39 and temporarily or finally connected to this. In the case of sheet materials 39 in the form of transfer films, mirror-inverted patterns or arrangements of decorative elements 5 can be created that are then transferred in an additional processing step that is independent of the placement, e.g., through fusing by means of heat as a whole onto an article of clothing or onto a different sheet material 39 and attached to this clothing or material.
[0033] Alternatively, decorative elements 5 , such as, e.g., rhinestones 5 a , could be arranged and attached with the placement device 3 according to the invention also directly on the final sheet material 39 —for example, on an article of clothing. In this case, the individual rhinestones 5 a are placed on the sheet material 39 directly with the back side opposite the visible side. The attachment on the sheet material 39 is realized directly after setting each rhinestone 5 a, wherein, e.g., micro-adhesive capsules on the back side of the rhinestones 5 a are crushed by the pressure of the press plunger 27 . In this way, the adhesive is released and the rhinestones 5 a are finally bonded with the sheet material 39 . Alternatively, adhesives can be activated, e.g., also through the supply of thermal energy or through light, in order to connect the decorative elements 5 to the sheet material 39 . In particular, there is also the ability to deposit an adhesive only directly before the application of each decorative element 5 onto this element or onto the corresponding connection point on the sheet material 39 . For this purpose, an adhesive cartridge (not shown) could be arranged, e.g., on the placement device 3 . Prior to setting the decorative element 5 , the control can trigger the dosing of a specified amount of adhesive from the adhesive cartridge onto the desired position, e.g., through a zigzag pivoting motion of the needle bar 23 . If necessary, for depositing the adhesive, the sheet materials 39 tensioned in the embroidery hoop 37 can be temporarily shifted into a different position corresponding to the adhesive cartridge and then shifted back again.
[0034] The placement device 3 according to the invention can also be constructed for feeding and attaching decorative elements 5 to sheet materials 39 by means of other connection techniques, such as, e.g., sewing, riveting, stamping, crimping, etc. (not shown).
[0035] For an additional embodiment of the invention, as shown in FIG. 2 , the magazine 7 is constructed as a cartridge 7 b or frame and is placed detachably on the base part 11 or is connected to this part in some other way. A first leg 11 a of the base part 11 is attached like in the embodiment according to FIG. 1 to the sewing foot presser bar 1 . The cartridge 7 b is attached to a second leg 11 b of the base part 11 , wherein the two legs 11 a, 11 b enclose an obtuse angle a of, e.g., 120° .
[0036] Rhinestones 5 a or other decorative elements 5 are stacked in an ordered way in a holding sleeve 43 of the cartridge 7 b adapted to the size of these decorative elements 5 . The schematic representation in FIG. 2 shows, for the sake of better clarity, only a few of the stacked rhinestones 5 a. A front-side removal opening 45 of the holding sleeve 43 can be covered by a closing mechanism. Advantageously, this closing mechanism comprises closing flaps 47 that are held by spring force in a closed position. On the back, a magazine spring 49 presses the stacked decorative elements 5 in the receiving sleeve 43 forward, wherein the front-most decorative element 5 is queued at the closed closing flaps 47 . Alternatively—for sufficient inclination of the second leg 11 b —instead of a magazine spring 49 , the force of gravity of the decorative element 5 can be used for its advance within the magazine 7 . In an arrangement according to FIG. 2 , the placement head 9 comprises angled transport lever 51 that can pivot about a first pivot axis Z 1 on the base part 11 with a take-up device 53 for transferring the front-most decorative element 5 from the cartridge 7 b and for transporting this element to the placement position on the sheet material 39 . In the representation in FIG. 2 , the transport lever 51 is in a loading position, wherein the take-up device 53 is arranged under the removal opening 45 of the cartridge 7 b. By lowering the needle bar 23 , first the closing flaps 47 are opened against the closing spring force. As a drive, here the needle bar movement is used in connection with a feeding device 35 shown schematically only as a rectangle for the sake of simplicity. In this way and through the application of force of the magazine spring 49 , the lowermost decorative element 5 is transferred from the cartridge 7 b to the take-up device 53 . It is held tight there predominantly, e.g., pneumatically, by negative pressure or with a spring-mounted clamp (not shown). For further downward movement of the needle bar 23 , the feeding device 35 closes the closing flaps 47 again. Through further downward movement of the needle bar 23 up to the lower reversing point, the placement head 9 is activated and here pivots the transport lever 51 with the decorative element 5 held on this lever into a placement position, as shown in FIG. 3 .
[0037] In FIGS. 2 and 3 , the arrows designated with B 1 show the lowering movement of the needle bar 23 , the arrows designated with B 5 show the pivoting movement of the transport lever 51 about the first pivot axis Z 1 , and the arrows designated with B 6 show the pivoting movement of a guide rod 55 that is held on the base part 11 so that it can pivot about a second pivot axis Z 2 . When the needle bar 23 is lowered and raised, its movement is transferred by a coupling element 57 to the guide rod 55 . This realizes a pivoting movement about the second pivot axis Z 2 . This movement is in turn transmitted by one or more hinges 59 supported on the transport lever 51 so that they can move, such that the placement head 9 rotates from the loading position according to FIG. 2 to the placement position according to FIG. 3 or vice versa. In the placement position, the decorative element 5 —similar to the embodiment according to FIG. 1 —is placed at the desired position on the sheet material 39 and attached to this material. For the subsequent raising of the needle bar 23 , the placement head 9 pivots back into the loading position, in order to receive the next decorative element 5 from the magazine 7 .
[0038] In addition to these two precisely described embodiments, the invention comprises a plurality of additional placement devices 3 that can be mounted on a sewing machine and that can be used in connection with the control of the sewing machine or a control with a higher rank than or interacting with this control for setting and optionally for fixing decorative elements 5 on sheet materials 39 . Advantageously, this sheet material 39 is tensioned in an embroidery hoop 37 or a different tensioning device and can be oriented relative to the placement head 9 in a way controlled by the control. In this way, functions (control functions and/or mechanical functions) of the sewing machine and/or accessory parts of the sewing machine can be used for placing decorative elements 5 . In particular, control functions of embroidery programs and movements of parts of the sewing machine can be used, in order to arrange decorative elements 5 or, in general, arbitrary individual parts on the sheet material 39 .
LEGEND OF THE REFERENCE SYMBOLS
[0000]
1 Sewing foot presser bar
3 Placement device
5 Decorative elements
5 a Rhinestones
7 Magazine
7 a Carrier tape
7 b Cartridge
9 Placement head
11 Base part
13 Sewing foot shaft
15 Retaining clip
17 Supply roll
19 Take-up roll
21 Guide web
23 Needle bar
25 Borehole
27 Press plunger
28 Restoring spring
29 Contact face
31 Contact plate
33 Needle holder
35 Feeding device
37 Embroidery hoop
39 Sheet material
41 Work plate
43 Take-up sleeve
45 Removal opening
47 Closing flaps
49 Magazine spring
51 Transport lever
53 Take-up device
55 Guide rod
57 Coupling element
59 Hinge | A placement device ( 3 ) for placing decorative elements ( 5 ) on a textile or non-textile sheet material is connected to a sewing machine. The decorative elements ( 5 ) are stored in an ordered way in magazines ( 7 ) and are fed in a controlled way by the control of the sewing machine to the appropriate set positions on the sheet material ( 39 ) and are connected to this material. | 3 |
This application is a continuation of prior application Ser. No. 08/708,795, filed Sep. 9, 1996, now U.S. Pat. No. 5,737,619, which application was a continuation-in-part of prior application Ser. No. 08/543,876, filed Oct. 19, 1995, now U.S. Pat. No. 5,572,643.
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates generally to computer networks and more particularly to methods for enhancing the operation of a client browser operating in a multi-server computer environment.
2. Description of the Related Art
The worldwide network of computers commonly known as the “Internet” has seen explosive growth in the last several years. Mainly, this growth has been fueled by the introduction and widespread use of so-called “web” browsers, which allow for simple graphical user interface (GUI)-based access to network servers, which support documents formatted as so-called “web pages”. The “World Wide Web” (WWW) is that collection of servers of the Internet that utilize the Hypertext Transfer Protocol (HTTP). HTTP is a known application protocol that provides users access to files (which can be in different formats such as text, graphics, images, sound, video, etc.) using a standard page description language known as Hypertext Markup Language (HTML). HTML provides basic document formatting and allows the developer to specify “links” to other servers and files. Use of an HTML-compliant client browser involves specification of a link via a Uniform Resource Locator or “URL”. Upon such specification, the client makes a tcp/ip request to the server identified in the link and receives a “web page” (namely, a document formatted according to HTML) in return.
There is a finite time period between the time the user initiates the link and the return of the web page. Even when the web page is returned quickly, there is an additional time period during which formatting information must be processed for display on the display interface. For example, most web browsers display inline images (namely images next to text) using an X bit map (XBM) or .gif format. Each image takes time to process and slows downs the initial display of the document. The user typically “sees” an essentially unrecognizable “image” on the display screen which only gradually comes into focus. It is only after the entire image is downloaded from the server and then processed by the browser that the user can fully access the web page itself. This “waiting” period is even longer when the client machine has a relatively slow modem, and often the user will have to wait many seconds before being able to see the in-line image and/or begin using the web page. This problem will be exacerbated when the next generation browser technology (such as Netscape Navigator 2.0) becomes more widely implemented because such browsers are being designed to handle much more complex download formats (for more interactive, dynamic displays).
BRIEF SUMMARY OF THE INVENTION
It is thus a primary object of the invention to enhance the operation of a web browser by causing the display of some useful information to the user during the period of user “downtime” that otherwise occurs between linking and downloading of a hypertext document identified by the link. Such information may include, without limitation, advertisements, messages, fill-in forms, notices from a service provider, notices from another Internet service (such as receipt of an e-mail message), or some third party notice.
It is another more particular object of the invention to use an Hypertext Markup Language comment (e.g., via an HTML comment tag) in a web page to store an information object related to a link and then formatting and displaying such information when the link is activated.
It is still another object of the invention to embed an information object within an existing web page so that the object is masked until a link to another web page is activated. Upon activation, the object is displayed to the user effectively as a “mini” web page while the browser calls the link and awaits for a reply and download.
For example, in one particular embodiment, the information object includes copyright management information for a hypertext document associated with a link in a currently-displayed page. Such information may include the name or other identifying information of a copyright owner, terms and conditions for uses of the work within the hypertext document, and such other information as may be prescribed or desired. When the user “hits” the link in the current page, the copyright management information (which is already present in the browser) is displayed as the new document is being accessed and downloaded. The copyright management information, for example, may inform the user of the terms and conditions of how the copyrighted content being downloaded can then be reused. The “time” period normally associated with the download is thus productive for both the user (since he or she no longer has to sit and wait for the display) as well as to the content provider.
According to the preferred embodiment, there is described a method of browsing the World Wide Web of the Internet using an HTML-compliant client supporting a graphical user interface and a browser. The method begins as a web page is being displayed on the graphical user interface, the web page having at least one link to a hypertext document preferably located at a remote server. In response to the user clicking on the link, the link is activated by the browser to thereby request downloading of the hypertext document from the remote server to the graphical user interface of the client. While the client waits for a reply and/or as the hypertext document is being downloaded, the browser displays one or more different types of informational messages to the user. Such messages include, without limitation, advertisements, notices, messages, fill-in forms, copyright information and the like. Preferably, the message information is in some way related to the hypertext document being accessed and downloaded, as in the case of copyright management information perhaps warning the user that the material being downloaded is subject to certain use restrictions of the copyright owner. Where the displayed information is related to the link, it is desirable that such information be embedded within the web page from which the link is launched. The information is preferably “hidden” within the web page using a hypertext markup comment tag.
The invention is preferably implemented in a computer having a processor, an operating system, a graphical user interface and a HTTP-compliant browser. In such case, the novel and advantageous features of the invention are achieved using a first means, responsive to activation of a link from a web page, for retrieving an information object masked within the web page, and a second means for displaying information from the information object on the graphical user interface as the browser establishes the link. Preferably, the information object is masked by an HTML comment tag, which may include other HTML tags nested therein to format the information in the object. This enables the support of complex “mini” web pages that are displayed and accessible to the viewer during otherwise non-productive periods when the browser is busy processing links to other documents or web sites.
The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention as will be described. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the following Detailed Description of the preferred Embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and the advantages thereof, reference should be made to the following Detailed Description taken in connection with the accompanying drawings in which:
FIG. 1 illustrates a computer network in which the present invention is implemented;
FIG. 2 illustrates a client computer supporting an HTML-compliant World Wide Web browser;
FIG. 3 is a flowchart diagram of a preferred method of the present invention for dynamic display of an information object during linking;
FIG. 4 is a representative graphical user interface illustrating browser navigation tools;
FIG. 5 is a representative web page illustrating a hypertext link;
FIG. 6 is a view of the HTML source code for the web page of FIG. 5;
FIG. 7 is an example of a modified version of the HTML source code for the web page illustrated in FIG. 5, showing an information object embedded therein through a comment tag;
FIG. 8 is a representative screen display illustrating how the information object appears as a “mini” web page upon activation of the hypertext link in the web page of FIG. 5;
FIG. 9 illustrates a computer program product comprising a substrate in which product data is encoded for carrying out various function of the invention when the product is used to control a processor;
FIG. 10 illustrates a portion of the computer network in which this invention is implemented having a master server for use in distributing information objects to a plurality of servers that support hypertext documents; and
FIG. 11 illustrates a preferred method of downloading an information object to a client computer to facilitate pre-caching of the object.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As represented in FIG. 1, the Internet is a known computer network based on the client-server model. Conceptually, the Internet comprises a large network of “servers” 10 which are accessible by “clients” 12 , typically users of personal computers, through some private Internet access provider 14 (such as Internet America) or an on-line service provider 16 (such as America On-Line, Prodigy, Compuserve, the Microsoft Network, and the like). Each of the clients may run a “browser,” which is a known software tool used to access the servers via the access providers. A server 10 operates a so-called “web site” which supports files in the form of documents and pages. A network path to a server is identified by a so-called Uniform Resource Locator or URL having a known syntax for defining a network connection.
The “World Wide Web” (WWW) is that collection of servers of the Internet that utilize the Hypertext Transfer Protocol (HTTP). HTTP is a known application protocol that provides users access to files (which can be in different formats such as text, graphics, images, sound, video, etc.) using a standard page description language known as Hypertext Markup Language (HTML). HTML provides basic document formatting and allows the developer to specify “links” to other servers and files. Use of an HTML-compliant client browser involves specification of a link via the URL. Upon such specification, the client makes a tcp/ip request to the server identified in the link and receives a “web page” (namely, a document formatted according to HTML) in return.
FIGURE 2 shows a block diagram of a representative “client” computer in which the present invention is implemented. The system unit 21 includes a system bus or plurality of system buses 31 to which various components are coupled and by which communication between the various components is accomplished. The microprocessor 32 is connected to the system bus 31 and is supported by read only memory (ROM) 33 and random access memory (RAM) 34 also connected to system bus 31 . The ROM 33 contains among other code the Basic Input-Output system (BIOS) which controls basic hardware operations such as the interaction and the disk drives and the keyboard. The RAM 34 is the main memory into which the operating system and application programs are loaded. The memory management chip 35 is connected to the system bus 31 and controls direct memory access operations including, passing data between the RAM 34 and hard disk drive 36 and floppy disk drive 37 . The CD ROM 42 , also coupled to the system bus 131 , is used to store a large amount of data, e.g., a multimedia program or large database.
Also connected to this system bus 31 are various I/O controllers: the keyboard controller 38 , the mouse controller 39 , the video controller 40 , and the audio controller 41 . The keyboard controller 38 provides the hardware interface for the keyboard 22 , the controller 39 provides the hardware interface for the mouse (or other point and click device) 23 , the video controller 40 is the hardware interface for the display 24 , and the audio controller 41 is the hardware interface for the multimedia speakers 25 a and 25 b . A modem 50 enables communication over a network 56 to other computers over the computer network.
The operating system 60 of the computer may be DOS, WINDOWS 3.x, WINDOWS '95, OS/2, AIX, or any other known and available operating system, and each computer is sometimes referred to as a machine. RAM 34 also supports a number of Internet access tools including, for example, the HTTP-compliant web browser 62 . Known browser software includes Netscape, Netscape Navigator 2.0, Mosaic, and the like. The present invention is designed to operate within any of these known or developing web browsers, which are preferably modified as described herein to achieve the dynamic display of information objects during web site linking activities. RAM 34 may also support other Internet services including simple mail transfer protocol (SMTP) or e-mail, file transfer protocol (FTP), network news transfer protocol (NNTP) or “Usenet”, and remote terminal access (Telnet).
HyperText Markup Language uses so-called “tags,” denoted by the <>symbols, with the actual tag between the brackets. Most tags have a beginning (<tag>) and an ending section, with the end shown by the slash symbol (</tag>). There are numerous link tags in HTML to enable the viewer of the document to jump to another place in the same document, to jump to the top of another document, to jump to a specific place in another document, or to create and jump to a remote link (via a new URL) to another server. Links are typically displayed on a web page in color or with an underscore. In response to the user pointing and clicking on the link, the link is said to be “activated” to begin the download of the linked document or text. For more details on HTML, the reader is directed to the HTML Reference Manual , published by Sandia National Laboratories, and available on the Internet at “http://www.sandia.gov/sci_compute/html.ref.html” or the HTML Quick Reference , published by the University of Kansas, and available_on the Internet at “http://kuhttp.cc.ukans.edu/lynx_help/HTML_quick.html”. Each of these publications are incorporated herein by reference.
A known HTML tag is a “comment,” which typically allows a web page developer to include text that is to be ignored by the browser. The syntax for a “comment” tag is denoted <!—text—>. HTML is an evolving language. Recent standards for new versions of this language propose to add SGML comment syntax to HTML elements. This proposal would begin a comment with a double dash encountered inside any HTML element (but no inside quotes), and treat every thing as comments (including any ““,””, or quote character) until the next occurring double dash. Such syntax allows HTML elements within a comment.
According to the present invention, an information “object” is preferably placed within a comment tag of a web page and thus is “ignored” by the browser in the formatting of the document then being displayed. This information object, however, is also saved to a separate file or cache within the client. A particular web page may have multiple information objects, with one or more objects associated with one or more links in the documents. Thus, for example, if the document has two links, one information object is associated with the first link and a second information object is associated with a second link, and so on. Or, multiple information objects may be associated with a single link. Or, the information object(s) may have no direct relation to the content of any link in the document. While in the preferred embodiment an HTML “comment” tag is used to mask the information object, those skilled in the art will recognize that other HTML commands and tags may be used for this purpose as well, including, for example, a tag dedicated to masking an information object within the currently-displayed page. For example, an information object may be hidden within a clickable image identified with an ismap tag. Also, an information object may be formatted as a “mini” web page by nesting HTML elements within a particular HTML comment tag.
As noted above, a web browser 62 running on the client uses a TCP/IP connection to pass a request to a web server running a HTTP “service” (under the WINDOWS operating system) or “daemon” (under the UNIX operating system). The HTTP service then responds to the request, typically by sending a “web page” formatted in the Hypertext Markup Language, or HTML, to the browser. The browser then displays the web page using local resources (e.g., fonts and colors).
A preferred operation of the inventive method is illustrated in the flowchart of FIG. 3 . The method begins at step 70 as a current web page is being displayed on the graphical user interface of the computer. It is assumed that this web page has embedded therein one or more comment tags, each of which (or perhaps several of which in combination) define an information object. Generally, although not required, each information object will be provided for one or more links in the web page being displayed. However, because the information object is embedded within a comment tag, it is hidden or “masked” and thus is ignored by the display routines of the browser. In step 72 , the method saves or stores the information object in memory or some dedicated portion of the RAM (e.g., a cache) so that it may be easily and quickly obtained. At step 74 , a test is made to determine whether a link associated with the information object has been activated. If so, the method continues at step 76 and issues a tcp/ip request to the network (assuming the link was to a URL). Step 78 represents the handshaking period during which the client waits for the appropriate response from the server. During this period, the client retrieves the information object (at step 80 ) and outputs the information (in step 82 ) to the user on the display. Steps 80 and 82 are shown in parallel to the handshaking and wait step 78 to emphasize the inventive concept of displaying useful information to the viewer during the link process. At step 84 , a test is then performed to determine whether the download and refresh of the display is complete. If so, the routine saves the information object at step 86 and opens up access to the hypertext document at step 88 .
FIG. 4 shows the browser navigation tool prior to download of the U.S. Patent and Trademark Office page (available at http://www.uspto.gov). FIG. 5 shows the web page as it exists on the display. This web page has various links including “Welcome to the United States Patent and Trademark Office.” FIG. 6 shows the HTML source code used to generate the web page of FIG. 5, and FIG. 7 shows this source code modified to include an information object 75 within a comment tag. This object displays the message “The PTO Welcomes You” when the “Welcome to the United States Patent and Trademark Office” link is activated. FIG. 8 shows the effect of this information object when the routine of FIG. 3 is carried out.
Although the invention has been described in terms of a preferred embodiment, those skilled in the art will recognize that various modifications of the invention can be practiced within the spirit and scope of the appended claims. Thus, for example, the information supplied to the user during the period between link activation and downloading of the hypertext document need not be merely a visual output. It is also envisioned that some or all parts of a particular message be conveyed to the user aurally (via a multimedia speaker set, for example) as well as on the display screen. The message itself may be retained on the screen as an in-line image or other text along with the downloaded hypertext document, and the browser includes appropriate means to queue the message to print and/or to save the message or allow the user to compose a response to the message. One such technique for responding to the message uses the HTML “fill-in” form tags. The browser may be suitably programmed to queue the mini web page for background printing whenever the link is activated.
Moreover, although in the preferred embodiment it is envisioned that the hypertext document (associated with the web page link) is located on a remote server, this is not a limitation of the invention. The display of informational messages may be effected whenever a link is activated, regardless of the location of the target document. Also, while the preferred embodiment has been described in the context of an Internet browser, the techniques of the invention apply whether or not the user accesses the Worldwide Web via a direct Internet connection (namely using an Internet access provider) or indirectly through some on-line service provider (such as America On-Line, Prodigy, Compuserve, the Microsoft Network, or the like). Thus the “computer network” in which the invention is implemented should be broadly construed to include any client-server model from which a client can link to a “remote” document (even if that document is available on the same machine or system).
It should also be appreciated that while in the preferred embodiment the information object is formatted and displayed upon activation of a link in a web page being currently displayed, this is not a limitation of the invention either. The information object need not be embedded within an existing web page, but rather may be embedded within the home page of the browser or supported elsewhere within the client itself. Thus, the information object may be displayed whenever a call to a web page is made, such as when a search to a particular URL is initiated, or when a previously-stored URL is launched (e.g., from a “View Bookmark” pull-down menu). Moreover, the client may store random information objects in the form of information advertisements (which in turn may include .gif files to produce images) so that the browser may call any such information at random. The browser may even be programmed to select which of the plurality of information objects to display based on a comparison of the type of web pages accessed by the user. Thus, for example, if the user accesses web pages relating to a particular service, the browser may be programmed to identify this access history and select predetermined information objects that will be of interest to the user (given that history).
The information objects may themselves be HTML “fill-in” forms that are retained on the display screen and may be filled in with information that the browser can then deliver back to some third party service provider. This enables the information objects to be used as mini survey forms for interactive, on-line surveys and the like, which would be especially advantageous for web site providers or other third parties. The information object may include its own embedded link so that the user can link to another URL directly from the object itself. Thus, for example, where the object is an advertisement, a user could read the ad and then hyperlink to the web page of the company that sponsors the ad.
As noted above, the information object may be automatically or selectively queued to the client printer upon display. This would enable the viewer to generate merchandise coupons and the like related to the web page being accessed. Thus the web site provider could offer the viewer some added incentive for accessing its web page by causing the printing of a redeemable coupon or other information token (e.g., a discount card, a receipt, etc.). All of these actions are initiated during the otherwise downtime between web page access and download, thereby significantly increasing the value of the on-line informational content provided to the user.
As used herein, the “information object” or “information” output to the viewer during the link process should be broadly construed to cover any and all forms of messages, notices, text, graphics, sound, video, tables, diagrams, applets and other content, and combinations of any of the above.
One of the preferred implementations of the “browser” of the invention is as a set of instructions in a code module resident in the random access memory of the user's personal computer. Until required by the computer, the set of instructions may be stored in another computer memory, for example, in a hard disk drive, or in a removable memory such as an optical disk (for eventual use in a CD ROM) or floppy disk (for eventual use in a floppy disk drive). As seen in FIG. 9, for example, the invention may be implemented as a computer program product comprising a computer-readable storage medium 90 having a substrate 92 , and program data 94 encoded on the substrate. The program data 94 implements various means for carrying out the above-described functions. The medium 90 may be a separate physical media such as a CD-ROM or floppy diskette, or it may comprise the client computer's hard drive, cache or other available memory, as would be the case if the program data or portions thereof are downloaded via the Internet.
In addition, although the various methods described are conveniently implemented in a general purpose computer selectively activated or reconfigured by software, one of ordinary skill in the art would also recognize that such methods may be carried out in hardware, in firmware, or in more specialized apparatus constructed to perform the required method steps.
The present invention is designed to be implemented with conventional HTML and enhancements thereto (including HTML 2.0, HTML 3.0, HTML with third party-supplied extensions such as NHTML, and the like), by an HTML-compliant browser, such as Netscape, Netscape Navigator 2.0, Mosaic, MSN, as such existing or developed programs are modified to include the functionality of the invention described above. The functionality may be built into the browser or added as a plug-in. Netscape Navigator 2.0 has in-line support for platform-independent application objects (e.g., applets written in Java, from Sun Microsystems). An applet resides on the server associated with a web page and is downloaded to the client browser after a link is established to the web page. The browser includes an engine for executing the downloaded applets. With this type of browser, the invention caches or otherwise stores a downloaded applet and later uses it, preferably when a new, related link is established. Thus, an “information object” according to the invention may include an applet which, for example, may generate an animated figure or icon, some aural output, a scrolling display, or a combination thereof. One of ordinary skill, however, will recognize that the inventive features of the invention, including the masking of “mini” hypertext documents within a web page and display of such documents upon link activation, may be applied to other Internet services as well as to HTTP compliant browsers. Thus, the invention would be useful to provide information to a user during an FTP access, an on-line chat, a posting to a bulletin board, or even during the sending and retrieval of e-mail. All such variations are considered within the scope of the invention.
FIG. 10 illustrates how information objects (e.g., product/service advertisements) may be distributed to one or more servers in the computer network, and FIG. 11 illustrates a preferred technique for downloading a hypertext document (with its associated information object) to the client machine. Turning initially to FIG. 10, a server 100 provides various control functions and includes an associated information warehouse 102 , which is preferably configured as a physically secure electronic repository for the storage of product/service descriptions and associated data. Server 100 may be controlled by an entity that contracts with one or more product/service providers 104 who desire to advertise their products or services through the information objects Entities 104 provide the advertisements, or descriptions and data used to create the advertisements, to the information warehouse preferably in an electronic manner. The information warehouse then electronically delivers the advertisements to one or more of the web servers 106 at which hypertext documents are supported. Advertisements can thus be “refreshed” or updated at any time or at regular intervals irrespective of whether the hypertext documents supported on web servers 106 change. Information objects may then be stored in the web server 106 in a dedicated area or directly embedded or associated with particular hypertext documents stored there.
An information object may include high bandwidth content including high resolution graphics, audio and video. In some instances then, the object may be relatively large in size such that “in-lining” the object an embedded link (e.g., within an HTML comment tag) may not be the most efficient way of downloading. In such case, it will be desirable (although not required) to store the information object in the web server 106 separate from any particular hypertext document so that the object may be downloaded to the client machine (with a hypertext document) by being “appended” at the distal or “backend” of the hypertext document that may be used to bring the object down to the client machine. (Of course, as noted above, information objects may be stored at the client machine in other ways besides being brought down by hypertext documents). This technique is illustrated in FIG. 11 .
The method begins at step 110 by downloading a first (or “source”) hypertext document (which then becomes the “current web page” within the context of FIG. 3 ). This document includes an associated information object, such as an advertising graphic that will be associated with some user-selectable display graphic (e.g., a link) in the first hypertext document. At step 112 , the browser at the client machine displays at least a portion of the first hypertext document (e.g., introductory text) while the download of the document (and the information object) continues at step 114 as a background process. By “background process,” it is meant that the process goes on without being directly or indirectly apparent to the user. This ensures that the user can begin browsing the first hypertext document irrespective of whether the download of the information object is complete. At step 116 , the routine continues by storing the information object in a storage of the client machine (e.g., a dedicated cache) as the user browses the first hypertext document. This technique ensures that delivery of relatively large information objects does not otherwise slow down the browsing session. To complete the routine, the user activates the user-selectable clickable graphic at step 118 to link to a second (or “target”) hypertext object. As discussed above, this retrieves the information object for display on the client interface as the new link is established. This is step 120 .
Under some circumstances, it may be desirable to download the first hypertext document completely and then download the information object separately (e.g., after a time delay), again preferably as a background process. In this manner, the user would not be directly aware that the information object was downloaded as he or she would be browsing the first hypertext document in the foreground. As far as the user is concerned, the first hypertext document is wholly “present” in the client (and is displayed), even though some of the information object is still being downloaded. Thus, as used herein, the concept of “appending” the information object to a hypertext document should be broadly construed to cover both the direct attachment of the object to the document (either directly or otherwise) as well as the serial transmission of the document and then the object (even if there is some finite time delay between such transmissions).
Delaying the download of the information object in this fashion can be advantageous, especially in the situation where the user receives the first hypertext document but then quickly decides to proceed to a URL that is not associated with a link in the document or to link to another URL (in the displayed document) that does not have an associated information object. In either case, the object would not be downloaded at all because the link with which it is associated would not be activated. Thus, it may be desirable to build in a fixed time delay between downloading of the first hypertext document and the information object(s) associated therewith so that if one or more predetermined events occur at the browser (with respect the document), no object download takes place.
Alternatively, information objects may be conveniently downloaded to the browser whenever there is “idle” time during the connection between the client and a server. Thus, an information object need not be appended to a hypertext document at all, but merely downloaded to the client during a period when the user is browsing the current page. Information objects downloaded in this manner are preferably stored in cache in a background process and may or may not be associated with a particular link in the current page. Upon link activation or some other event, however, an object is displayed to the user to provide seamless browsing.
Having thus described my invention, what I claim as new and desire to secure by Letters Patent is set forth in the following claims. | A method of display as a user of the Internet uses a client machine during an Internet transaction (e.g., e-mail, file transfer, bulletin board, chat or browsing). The client machine supports a graphical user interface and mechanisms that provide such Internet services. The method locally stores information content served during idle periods when the user's connection to the network is live. During a given Internet transaction, the information content is retrieved and displayed to provide entertainment or information as the user waits for the Internet transaction to be completed. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a control circuit for a construction machine for switching a plurality of actuators.
[0003] 2. Description of the Related Art
[0004] Conventionally, a hydraulicexcavator equipped with a boom swing apparatus is known, for excavating a small place at the corner by swinging a boom left and right around a vertical axis. As an operating means for operating a boom swing cylinder, there is an operating means in which a foot pedal is used. Such an equipment with the foot pedal limits space in foot side. Also, equipment with a nibbler or a breaker as an option increases the number of pedals and makes operations thereof complex.
[0005] For this reason, an operation lever can be used, which performs together operation of the boom swing cylinder and operation of an actuator, for example a revolving motor that is not operated in combination of boom swing.
[0006] In this case, when after switching from revolving to boom swing, if the switching operation is not recognized, there is a problem that mis-operation can occur that the revolving is derived from the operation carried out for a boom swing purpose.
SUMMARY OF THE INVENTION
[0007] An object of the present invention is to provide a control circuit for a construction machine capable of certainly preventing wrong operation in a case that a plurality of actuators are operated by means of only one control lever.
[0008] The control circuit for a construction machine according to the present invention has following constitution.
[0009] The present invention comprises: a control lever for carrying out operations of a first actuator and a second actuator in common; a switching valve or a selector valve for supplying pilot pressure output from a remote control valve by means of operation of the control lever to a control port in any one of the first and the second actuators; a control member for supplying a switching signal to the switching valve; a detector for detecting whether the pilot pressure is output from the remote control valve or not; and a switching controller for switching a change-over position in the switching valve from the first actuator to the second actuator when the switching signal is output from the control member and holding the position at the second actuator when output of the pilot pressure is detected by the detector.
[0010] According to the present invention, if the control member is operated, the switching valve switches a pilot pressure supply place to which the pilot pressure is output from the remote control valve of the control lever, from the first actuator to the second actuator, and then the detector detects the pilot pressure if the pilot pressure appears in a pilot line by means of operation of the control lever. The switching control means holds the switching valve at the second actuator when the switching signal is output from the control member and when output of the pilot pressure is detected by the detector. Thereby, switching from the first actuator to the second actuator does not occur as long as the control member is not operated. Also, when the control lever is operated in a state that the control member is operated to switch the position of switch to the second actuator, the position cannot be switched to the first actuator even if the control member is off, as long as the control lever is not restored in neutral position. Therefore, wrong operation can be prevented in switching. Also, even if a finger is taken off the control member during operation, a bad situation that the position of switch is switched to other actuator can be prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a diagram showing a control circuit for a construction machine according to one embodiment of the present invention;
[0012] [0012]FIG. 2 a is a plan view of the construction machine for explaining boom swing operation and FIG. 2 b is a side view thereof;
[0013] [0013]FIG. 3 is a circuit diagram showing constitution of a switching control circuit shown in FIG. 1; and
[0014] [0014]FIG. 4 is a schematic view showing operations of a control lever.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Now, the present invention will be explained on the basis of embodiments shown in the drawings. These embodiments are only preferred embodiments of the present invention and the present invention is not limited to them.
[0016] [0016]FIG. 1 shows one embodiment of a control circuit for a construction machine according to the present invention.
[0017] In FIG. 1, a variable capacity type of hydraulic pump 2 and a pilot pump 3 are operated, respectively, by means of driving of an engine 1 equipped in an upper rotating body of the construction machine.
[0018] Hydraulic oil discharged from the hydraulic pump 2 is supplied to a right traveling control valve 4 , a boom control valve 5 , a bucket control valve 6 , a boom swing control valve 7 and a control valve 8 for a crusher/breaker as an option apparatus, arranged in a center bypass line LC on the left of FIG. 1. The hydraulic oil is also supplied to a left traveling control valve 9 , a revolving control valve 10 and an arm control valve 11 , arranged in a center bypass line RC on the right of FIG. 1. The hydraulic oil discharged from the pilot pump 3 is used as a pressure source for various controllers.
[0019] A straight traveling valve 12 provided upstream in the traveling control valve 4 , 9 has positions of switch comprised of a, b and is normally held at the position a.
[0020] At the position a, the hydraulic oil from the hydraulic pump 2 is independently supplied to the left center bypass line LC and the right center bypass line RC. If, in a state that the right and left traveling levers are operated to the same position, for example the boom or the arm is operated, then the straight traveling valve 12 is switched from the position a to the position b. Accordingly, the hydraulic oil from the hydraulic pump 2 flows in parallel to the left center bypass line LC and the right center bypass line RC. At that time, even if a combined operation is carried out such that the boom is risen and fallen while a traveling motor 16 is driven, the hydraulic oil from the hydraulic pump 2 is supplied equally to the left and the right traveling motors. By means of this, the straight traveling can be kept. Also, in the drawing, 13 is a conflux valve for increasing the boom-up speed and 14 is a cut valve for making the hydraulic oil flow in the left center bypass line LC.
[0021] Next, switching operation of the control lever will be explained with reference to FIG. 4. As shown in FIG. 4, by operating a switch 51 provided at upper grip part of a left control lever sq, revolving of an upper rotating body and boom swing are switched. That is, by means of revolving operation, the operation in {circle over (1)} direction becomes right revolving and the operation in {circle over (2)} direction becomes left revolving. When the switch 51 is pushed, the operation in {circle over (1)} direction makes boom right swing and the operation in {circle over (2)} direction makes boom left swing. For reference, operations of lever for arm releasing and excavating, boom rising and falling, or bucket excavating and releasing are exemplified in FIG. 4. That is, in the left control lever, {circle over (1)} indicates right revolving, {circle over (2)} indicates left revolving, {circle over (3)} indicates arm releasing and {circle over (4)} indicates arm excavating. Also, in the right control lever, {circle over (5)} indicates boom falling, {circle over (6)} indicates boom rising, {circle over (7)} indicates bucket excavating and {circle over (8)} indicates bucket releasing.
[0022] Also, in a case that the switch 51 is a toggle switch, a tumbler switch or the like, the switch is fixed to either the boom swing or the revolving whenever the switch 51 is operated. Also, in a case that the switch 51 is an automatic restoring type of push button switch, it is switched to the boom swing only when pushed with fingers. Here, the present invention is not limited to the switching mode of the control lever as described above.
[0023] Now, a switching operational circuit of the revolving motor (as first actuator) and the boom swing cylinder (as second actuator) related to the present invention will be explained. Explanation for operation of actuators except for them will be omitted for simplification.
[0024] The boom swing cylinder 15 is connected to the boom control valve 7 . If the control valve is switched from the neutral position to the position c, the hydraulic oil is supplied to a head side of the boom swing cylinder 15 . At that time, as shown in FIGS. 2 a and 2 b , the boom 30 can be swung, for example, right (e direction in the drawing) around the vertical axis VA. If the control valve is switched to the position d, the hydraulic oil is supplied to rod side of the boom swing cylinder 15 . At that time, the boom 30 can be swung left (f direction in the drawing) around the vertical axis VA.
[0025] The revolving motor 16 is connected to the revolving control valve 10 . If switched from the neutral position to the position e, the revolving motor 16 is rotated in g direction to rotate the upper rotating body 31 (see FIG. 2 b ), for example, right. Also, if switched to the position f, the upper rotating body can be rotated left.
[0026] The pilot line of the boom control valve 7 and the pilot line of the revolving control valve 10 are connected to the outlet port of the switching valve 17 , respectively.
[0027] This switching valve 17 is normally positioned at the position i, and is connected to the control port of the revolving control valve 10 . If switching signals is received from the switching control circuit 18 as a switching controller, the switching valve 17 is switched to the position j by means of hydraulic signal sent via the electromagnetic valve 17 a . Accordingly, the pilot pressure is supplied to the control port of the boom swing cylinder 15 .
[0028] The inlet port of the switching valve 17 is connected to the remote control valve 19 of the left control lever 50 (see FIG. 4). If the left control lever 50 is shifted in {circle over (1)} direction, the pilot pressure is derived from the remote control valve 19 a . Also, if the lever is shifted in {circle over (2)} direction, the pilot pressure is derived from the remote control valve 19 b . These pilot pressures flow through the respective pilot lines 20 a and 20 b to the inlet port of the switching valve 17 .
[0029] These pilot lines 20 a and 20 b are provided with pressure switches 21 a and 21 b as detector, respectively. If any one of the pilot lines 20 a and 20 b detects the pilot pressure, the signal is output to the switching control circuit 18 .
[0030] Therefore, in the present invention, the detector is comprised of pressure switches provided in the pilot lines passing from the remote control valve to the switching valve. In this case, because the detector is constructed with the conventional pressure switch for detecting operational pressure from the remote control valve, the control circuit of the present invention can be embodied without new sensor required.
[0031] Next, construction of the switching control circuit 18 will be explained with reference to FIG. 3.
[0032] First, if the push-button switch (control member) 51 provided in grip of the left control lever 50 is pushed, an electromagnetic coil R 3 of the relay 180 is excited. As a result, the contact point R 3-a is closed. Thereby, the solenoid of the electromagnetic valve 17 a is turned on and the electromagnetic valve 17 a is switched from the intercepting position k to turn-on position or conducting position 1 .
[0033] If the hydraulic signal is applied to the control port of the switching valve 17 via the electromagnetic valve 17 a , the switching valve 17 is switched to the position j. As a result, the pilot lines 20 a and 20 b are connected to the control port of the boom swing control valve 7 . Accordingly, {circle over (1)} and {circle over (2)} operations by the left control lever 50 function as the boom swing operations.
[0034] If the contact point R 3-a is closed, current flows through the signal line 180 a to the relay 181 . As a result, the electromagnetic coil R 2 is excited and the contact point R 2-a is closed. In this state, if the left control lever 50 is shifted in any of {circle over (1)} direction and {circle over (2)} direction, the pressure switch 21 a or 21 b is closed to turn on electricity and to make current flow. This current flows via the contact point R 2-a and diode 182 to the electromagnetic coil R 3 . As a result, the relay 180 is self-held. That is, even when fingers are taken off the switch 51 , the switching valve 17 is held at the position j. Accordingly, the boom swing operation is continued.
[0035] Also, if the revolving operation is carried out when the switch 51 is not pushed, the electromagnetic coil R 1 of the relay 183 is excited to open the contact point R 1-a . As a result, even when the switch 51 is pushed, the relay 180 and 181 do not function and the switching valve 17 is never switched to the boom swing control valve 7 . That is, when the switch 51 is not pushed, the operation mode is always fixed to the revolving operation. Only when the switch 51 is pushed, the operation mode is switched to the boom swing operation.
[0036] In the present invention, a relay is provided between the control member and the switching valve, the relay being constructed to be self-held with signal output from the detector. In this case, the control circuit of the present invention can be embodied with a simple construction such that a relay circuit is added.
[0037] As described above, in the control circuit of the present embodiment, the operation mode is not switched to the boom swing operation as long as the switch 51 is not pushed. Moreover, after the operation mode is switched to the boom swing operation, the boom swing operation is continued as long as the left control lever 50 is not restored to the neutral position. As a result, the revolving operation and the boom swing operation can be switched surely and safely. Also, even when fingers are taken off the switch 51 during the boom swing operation, the operation mode is never switched to the revolving operation.
[0038] Moreover, although the relay is used to control in sequence in the above embodiment, the switching control means of the present invention is not limited to it and a microcomputer may be used to control in software.
[0039] Also, the first actuator and the second actuator in the present invention are comprised of a revolving motor for revolving the upper rotating body and a boom swing cylinder for swinging the boom left and right around the vertical axis, respectively, in the above embodiment. In addition, the first actuator may be the revolving motor and the second actuator may be an offset cylinder for offsetting the boom in machine-width direction.
[0040] In this case, when the revolving operation and the boom swing operation are carried out by means of only one control lever, the revolving operation of the upper rotating body can be carried out during the control member is not operated. Also, only when operation of the control member is carried out, the boom swing operation can be carried out. Even when operation of the control member is released during the boom swing operation, the boom swing operation can be continued as long as the control lever is not restored to the neutral position. As a result, a trouble that the upper rotating body is revolved rapidly by means of wrong operation can be prevented.
[0041] In brief, if it is combination of actuators without combined operation, for example, any lever operation in standard operating mode prescribed with ISO and lever operation of option apparatus can be combined.
[0042] As described above, although one embodiment of the present invention is disclosed, the scope of the protection of the present invention is not limited to it. | The present invention is a control circuit for a construction machine for using a control lever for revolving and boom swing in common and switching pilot pressure via a switching valve, comprising: a switch for supplying a switching signal to the switching valve; a pressure switch for detecting whether the pilot pressure is output from a remote control valve or not; a switching control circuit for switching a position of switch to a position for a boom swing cylinder when the switching signal is output from the switch and holding the position of switch at the position for the boom swing cylinder when the pilot pressure is detected by the pressure switch, to thereby prevent wrong operation in switching. | 4 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.